Laws of the Lizard (2017) - full transcript
Few creatures have revealed as many biological secrets about the workings of life on Earth as the backyard lizard known as the anole. Join biologists Neil Losin and Nate Dappen on their ...
Neil Losin: PICTURE IN YOUR MIND
THE CREATURES WE STUDY
TO REVEAL HOW LIFE WORKS.
[GROWLS]
WHAT DO YOU SEE?
FRUIT FLIES,
WHICH REVOLUTIONIZED GENETICS?
CHIMPANZEES, WHICH TEACH US
ABOUT THE ORIGINS
OF INTELLIGENCE?
WHAT ABOUT MICE, WHICH HELP US
UNDERSTAND HUMAN DISEASES?
WHATEVER YOU'RE IMAGINING,
IT PROBABLY ISN'T A LIZARD
IN A SUBURBAN BACKYARD.
BUT RESEARCHERS STUDYING
ONE SPECIAL GROUP OF LIZARDS
ARE DISCOVERING ANSWERS
TO BIG QUESTIONS
ABOUT LIFE ON EARTH.
♪
HOW DO ANIMALS ADAPT
TO DIFFERENT ENVIRONMENTS?
HOW CAN SO MANY SPECIES
COEXIST IN ONE PLACE?
AND HOW FAST
CAN EVOLUTION HAPPEN?
Man: WHEN SCIENTISTS
HAVE HAD BIG QUESTIONS
ABOUT THE WORLD AROUND US,
TIME AND TIME AGAIN
OVER THE LAST CENTURY,
THEY'VE TURNED TO ANOLES
TO ANSWER THOSE QUESTIONS.
Neil: MY NAME IS NEIL LOSIN.
Nate Dappen:
AND MY NAME IS NATE DAPPEN.
NEIL AND I ARE BIOLOGISTS
AND WILDLIFE FILMMAKERS.
WE'RE ON A YEAR-LONG JOURNEY,
TRAVELING FROM REMOTE FORESTS
AND TINY ISLANDS
TO HIGH-TECH LABS
AND BIG CITIES,
ALL IN PURSUIT OF THESE LIZARDS
THAT DEFY OUR EXPECTATIONS.
AS THEY BATTLE THEIR RIVALS,
EVADE PREDATORS,
AND SURVIVE
IN HOSTILE ENVIRONMENTS,
THESE LITTLE LIZARDS
SEEM TO MEET EVERY CHALLENGE
WITH AN INGENIOUS ADAPTATION.
IN THE PROCESS,
THEY REVEAL HOW SIMPLE RULES,
WHAT NEIL AND I
CALL THE LAWS OF THE LIZARD,
CAN EXPLAIN
THE COMPLEXITY OF NATURE.
YES, YES, YES, YES, YES!
OH!
YOU GOT HIM!
[LAUGHS]
Neil: ONE OF THE RAREST ANOLES
IN THE WORLD.
Nate: COME WITH US AND DISCOVER
HOW THESE UNASSUMING LIZARDS
ARE CHANGING THE WAY WE THINK
ABOUT LIFE ON EARTH.
♪
Neil: EVERY LIZARD BIOLOGIST
REMEMBERS THEIR FIRST,
THAT IS, THE FIRST LIZARD
THEY EVER STUDIED.
THE LIZARD
THAT TOOK NATE'S INNOCENCE
WAS A STRANGE COSTA RICAN
SPECIES CALLED THE RIVER ANOLE.
NATE AND I BOTH GOT OUR PhDs
STUDYING LIZARDS.
AND OVER THE LAST TEN YEARS,
WE'VE BECOME COLLABORATORS,
BUSINESS PARTNERS,
AND BEST FRIENDS.
THROUGH ALL OF THAT,
NATE HAS NOT SHUT UP
ABOUT THAT RIVER ANOLE,
SO WE'RE STARTING OUR JOURNEY
IN NATE'S OLD STOMPING GROUNDS
IN THE MOUNTAINS OF COSTA RICA
TO FIND THE LIZARD
THAT WAS SO INTERESTING,
IT CONVINCED NATE
TO BECOME A BIOLOGIST.
♪
Nate: IF YOU GET
A CHANCE TO SEE A RIVER ANOLE,
THE FIRST THING THAT IT'LL DO
IS SORT OF MOVE
TO THE OTHER SIDE OF THE ROCK
OR THE BRANCH THAT IT'S ON.
IF IT THINKS
THAT YOU'RE A REAL THREAT,
IT WILL DO SOMETHING AMAZING.
♪
SOMETIMES, RIVER ANOLES
REAPPEAR DOWNSTREAM
AFTER JUST A FEW SECONDS.
IT'S HARD TO PREDICT
EXACTLY WHERE THEY'LL POP UP.
OTHER TIMES,
THEY JUST SEEM TO VANISH.
WHAT ARE THEY DOING
WHEN THEY DISAPPEAR?
Neil: ALMOST AS SOON AS WE GOT
OUR CAMERA UNDER THE WATER,
WE WERE DOCUMENTING A BEHAVIOR
THAT'S ESSENTIALLY
UNKNOWN TO SCIENCE.
Nate: ONE FEMALE CLUNG
TO A ROCK UNDERWATER
FOR ALMOST TEN MINUTES.
WE FIGURED SHE MUST BE
HOLDING HER BREATH,
BUT WHEN WE WATCHED OUR FOOTAGE,
WE SAW SOMETHING
THAT BLEW US AWAY.
LOOK CAREFULLY, AND YOU CAN SEE
A LITTLE AIR BUBBLE
GROWING AND SHRINKING
ON HER HEAD.
IT LOOKS LIKE
SHE'S REBREATHING HER AIR,
LIKE A DEEP-SEA DIVER
RECYCLING HER OXYGEN SUPPLY.
RESEARCHERS
AT THE UNIVERSITY OF TORONTO
ARE NOW TRYING TO UNDERSTAND
THIS REBREATHING BEHAVIOR.
THE FIRST LAW OF THE LIZARD--
EXPECT SURPRISES.
♪
IT'S AN EXCITING START
TO A QUEST WE'VE BEEN THINKING
ABOUT EVER SINCE WE MET.
Neil: I MET NATE DAPPEN IN 2008
IN COSTA RICA
WHEN WE WERE BOTH STUDENTS
ON THE SAME
TROPICAL BIOLOGY COURSE.
Nate: WE WERE SO SIMILAR,
IT WAS KIND OF SPOOKY.
AND SO, WE'RE THE SAME HEIGHT,
SAME SIZE.
WE CAN FIT INTO EACH OTHER'S
CLOTHES IF WE NEED TO.
AND WE WERE BOTH
STUDYING EVOLUTION,
AND WE WERE BOTH
REALLY INTO PHOTOGRAPHY,
AND SO WE EITHER
HAD THE DECISION
TO DESTROY EACH OTHER
OR JOIN FORCES.
Neil: LUCKILY FOR NATE,
WE DECIDED
NOT TO DESTROY EACH OTHER.
INSTEAD, WE STARTED WORKING
TOGETHER ON EXPERIMENTS,
PHOTOGRAPHY PROJECTS,
AND EVENTUALLY ON FILMS.
Nate: AND WE SORT OF HAD
THIS DECISION TO MAKE--
DID WE WANT TO CONTINUE ON
AND BE RESEARCHERS,
OR DID WE WANT
TO GO INTO FILM FULL TIME?
AND WE SORT OF DECIDED TOGETHER
THAT WE WERE GONNA
TAKE THE PLUNGE
AND START MAKING SCIENCE FILMS
PROFESSIONALLY.
Neil: EVER SINCE, NATE AND I
HAVE TRAVELED AROUND THE WORLD
MAKING FILMS
ABOUT WILDLIFE AND SCIENCE.
ONE FILM
WE'VE ALWAYS WANTED TO MAKE
IS THE STORY
OF THESE LITTLE CREATURES
THAT HAVE HAD A HUGE IMPACT
ON OUR UNDERSTANDING OF LIFE.
WE WANTED TO TELL
THE STORY OF ANOLES.
Nate: WE'VE ALL SEEN
DOCUMENTARIES
WITH LIONS AND SHARKS
AND ELEPHANTS,
BUT NONE OF THOSE SPECIES
HAVE HAD REMOTELY
THE SAME KIND OF IMPACT
ON OUR UNDERSTANDING OF BIOLOGY
AS ANOLES HAVE.
Neil: FROM EVOLUTION
TO ECOLOGY, GENETICS,
PHYSIOLOGY,
EVEN CONSERVATION BIOLOGY.
♪
SO, WHAT ARE ANOLES?
THEY'RE A GROUP OF
CLOSELY RELATED LIZARD SPECIES
THAT LIVE
ALL OVER THE AMERICAN TROPICS.
THERE ARE MORE THAN 400 SPECIES
OF ANOLES
WITH A WIDE RANGE OF COLORS,
SIZES, AND BEHAVIORS.
BUT DESPITE ALL THIS VARIATION,
ANOLES SHARE TWO TRAITS THAT SET
THEM APART FROM OTHER LIZARDS,
AND THAT'S THE DEWLAP,
WHICH IS A COLORFUL FLAP OF SKIN
THAT EXTENDS FROM THE THROAT,
AND STICKY, ADHESIVE TOE PADS
ON THEIR FEET,
WHICH ALLOW THEM TO CLIMB
ON SMOOTH SURFACES LIKE LEAVES.
SOME OTHER LIZARDS
HAVE DEWLAPS OR TOE PADS,
BUT ONLY ANOLES HAVE BOTH.
Nate: THE DEWLAP
IS USED TO COMMUNICATE
WITH MEMBERS
OF THE SAME SPECIES.
MALES USE IT
TO TELL OTHER MALES,
"HEY, THIS IS MY TERRITORY.
DON'T MESS WITH ME,"
OR THEY USE IT TO SHOW FEMALES,
"HEY, COME OVER HERE,
I'VE GOT THIS GREAT TERRITORY,
AND I'M REALLY ATTRACTIVE."
Neil: TO WARD OFF
A POTENTIAL RIVAL,
A MALE ANOLE WILL PERFORM
A SORT OF RITUALIZED DISPLAY.
HE'LL DO PUSH-UPS,
AND HE'LL FLASH HIS DEWLAP.
IF THAT DOESN'T
INTIMIDATE HIS RIVAL,
THEIR ENCOUNTER CAN ESCALATE
INTO A VIOLENT BATTLE.
♪
IF THE MALE
CAN DEFEND HIS TERRITORY,
HE'LL HAVE OPPORTUNITIES
TO COURT FEMALES
AND, IF HE'S LUCKY,
A CHANCE TO MATE.
♪
Nate: ANOLES ARE FIERCE
HUNTERS THAT CHASE DOWN AND EAT
ALMOST ANYTHING
THAT FITS IN THEIR MOUTHS...
FROM INSECTS AND SPIDERS
TO OTHER LIZARDS,
EVEN MEMBERS
OF THEIR OWN SPECIES.
♪
ONE THE MOST SURPRISING THINGS
ABOUT ANOLES
IS THAT GENERATIONS
OF SCIENTISTS
HAVE DEDICATED THEIR LIVES
TO STUDYING THESE CRITTERS.
TO UNDERSTAND WHY,
WE NEED TO INTRODUCE YOU
TO THE MAN AT THE CENTER
OF THE ANOLE UNIVERSE.
Man: IF YOU MENTION
ANOLES TO ANYBODY,
THEY'RE GOING TO THINK
OF JONATHAN LOSOS.
Man: FIRST PERSON THAT
JUMPS TO MIND IS JONATHAN LOSOS.
Man: JONATHAN LOSOS.
Man: JONATHAN LOSOS.
Woman: JONATHAN LOSOS.
Man: YEAH, I WOULD SAY
JONATHAN LOSOS IS THE BOB DYLAN
OF ANOLE LIZARD BIOLOGY.
Woman: THE LEONARDO DA VINCI.
Man: THE GODFATHER.
Woman: THE JOHN LENNON.
Man: THE BARACK OBAMA.
Man: THE...
...ALBUS DUMBLEDORE
OF LIZARD BIOLOGY.
Man: AND JONATHAN
HAS LITERALLY WRITTEN THE BOOK
ON, ON ANOLE BIOLOGY.
Jonathan Losos: THE TWO MOST
COMMON WAYS OF PRONOUNCING IT
ARE "AN-OLE" AND "UH-NOLE."
AND THERE'S NO RIGHT OR WRONG.
AND I ACTUALLY GO
BACK AND FORTH, EITHER ONE,
FOR NO PARTICULAR REASON.
Man: I MEAN, HE JUST
REALLY LOVES ANOLIS LIZARDS.
HE JUST ALSO HAPPENS TO BE
A BRILLIANT SCIENTIST.
Nate: WE CAUGHT UP
WITH JONATHAN IN COSTA RICA
TO FIND OUT HOW HIS NAME
BECAME SYNONYMOUS WITH ANOLES.
Jonathan:
THERE'S A PICTURE OF ME
WHEN I WAS ABOUT EIGHT IN MIAMI,
AND I'D JUST CAUGHT
A, A LITTLE GREEN ANOLE.
IT'S A PICTURE OF ME LOOKING
VERY DOOFY WITH A GREEN ANOLE,
SO I GO WAY BACK WITH THEM.
Nate: IT SOUNDED LIKE DESTINY
THAT JONATHAN WOULD BECOME
AN ANOLE RESEARCHER.
Jonathan: AND SO I'VE BEEN
STUDYING ANOLES EVER SINCE.
Nate: AND DO YOU KNOW
ANY GOOD ANOLE PUNS?
Jonathan: WELL, ONLY ONE.
IT'S ANOLE-Y, BUT A GOODIE.
[IMITATES RIMSHOT]
Neil: OH!
Nate: I FIRST MET JONATHAN
WHEN I WAS A GRADUATE STUDENT,
AND HE TRIED TO CONVINCE ME
TO STUDY ANOLES.
Jonathan: I REMEMBER THAT.
I SAID,
THE GUY'S LIVING IN MIAMI,
AND HE WANTS TO GO TO SPAIN
TO DO HIS PhD
WHEN THERE ARE ANOLES
IN HIS BACKYARD.
CRAZY MAN!
Nate: I KNOW, BUT WHAT I DID
INSTEAD IS I CONVINCED THIS GUY.
Neil: HE PAID IT FORWARD.
Jonathan: WELL, ALL RIGHT.
EXCELLENT.
SO, FAILURE, SUCCESS.
THAT'S HOW I LOOK AT IT.
Neil: I SPENT THREE YEARS
STUDYING ANOLES IN MIAMI,
WHERE THEY'RE JUST PART OF LIFE.
YOU'D RUN INTO PEOPLE--
JOGGERS, DOG WALKERS-
AND MOST PEOPLE
HAVE SOME AWARENESS OF ANOLES.
BUT PEOPLE ARE USUALLY SURPRISED
TO LEARN THAT I'M NOT JUST
THIS ONE RANDOM WEIRDO
OUT THERE IN THE PARK,
BUT THERE ARE ACTUALLY
HUNDREDS OF BIOLOGISTS,
INCLUDING SOME OF
THE TOP SCIENTISTS IN THE WORLD,
WHO ARE STUDYING
THESE PARTICULAR LIZARDS.
Jonathan:
IT'S HARD TO KNOW FOR SURE
HOW MANY PAPERS ON ANOLES HAVE
BEEN PUBLISHED OVER THE YEARS.
I WOULD GUESS 5,000,
MAYBE 10,000.
Nate: SO, A LOT OF PEOPLE
STUDY ANOLES,
BUT WHERE DOES
THE ANOLE STORY BEGIN?
A GOOD PLACE TO START IS
THE WORLD'S LARGEST COLLECTION
OF REPTILES AND AMPHIBIANS
AT THE SMITHSONIAN NATIONAL
MUSEUM OF NATURAL HISTORY.
Kevin de Queiroz: WE HAVE
ALMOST 600,000 SPECIMENS
OF AMPHIBIANS AND REPTILES.
OF THOSE 600,000,
ABOUT 18,000 OF THEM
ARE ANOLIS LIZARDS.
Neil: THESE SCIENTIFIC
COLLECTIONS ARE LIKE
A COMBINATION DICTIONARY AND
ENCYCLOPEDIA OF LIFE ON EARTH.
THEY SHOW SCIENTISTS
WHAT SPECIES LOOK LIKE TODAY
AND HOW THEY'VE CHANGED
OVER TIME.
UNFORTUNATELY, ANOLE FOSSILS
ARE INCREDIBLY RARE,
SO, UNTIL RECENTLY, THE FOSSIL
RECORD DIDN'T SHED MUCH LIGHT
ON THE ANCIENT HISTORY
OF ANOLES.
BUT ALL THAT CHANGED
WITH RECENT DISCOVERIES
ON THE ISLAND OF HISPANIOLA.
Kevin: THERE'S A FAMOUS
AMBER INDUSTRY
THAT'S BEEN GOING ON THERE
FOR A LONG TIME.
THEY'RE USED FOR JEWELRY,
BUT OCCASIONALLY YOU FIND
BABY LIZARDS IN THERE, TOO.
Nate: ONE OF THE MOST
BEAUTIFUL THINGS I'VE EVER SEEN
WAS A 20-MILLION-YEAR-OLD ANOLE
TRAPPED IN AMBER.
THERE WERE BUBBLES IN THE STONE
THAT TRULY CONTAINED THE AIR
THAT THAT LIZARD BREATHED.
THESE LIZARDS TRAPPED IN AMBER
SHOW US THAT ANOLES
HAVE BEEN LIVING AND EVOLVING
ON THE ISLANDS OF THE CARIBBEAN
FOR TENS OF MILLIONS OF YEARS.
THAT HISTORY IS PRESERVED
IN THE JARS THAT LINE THE WALLS
OF THESE COLLECTIONS.
LOOK CLOSELY,
AND YOU'LL START TO APPRECIATE
THAT THESE LITTLE LIZARDS
ARE THE KEY TO A BIG STORY--
THE STORY OF LIFE
AND HOW IT EVOLVES.
TO DISCOVER THE SECRETS
THAT ONLY ANOLES CAN REVEAL,
WE NEED TO FOLLOW
IN THE FOOTSTEPS
OF GENERATIONS OF SCIENTISTS.
WE NEED TO GO TO THE CARIBBEAN.
HERE IN PUERTO RICO,
A WORLD OF SURPRISES IS WAITING.
Neil: IN THE CARIBBEAN, LAND
COMES IN ALL SHAPES AND SIZES.
IF YOU VISIT THE BIGGEST ISLANDS
IN THE CARIBBEAN,
THE FIRST THING YOU'LL NOTICE
IS THAT THEY'RE CRAWLING
WITH ANOLES.
LOOK CLOSELY,
AND YOU'LL SEE THAT THESE ANOLES
COME IN ALL SHAPES AND SIZES,
TOO.
AND JUST LIKE BODYBUILDERS
AND BALLERINAS,
AN ANOLE'S ANATOMY
CAN TELL US A LOT
ABOUT HOW IT MAKES A LIVING.
STEP INTO A PUERTO RICAN FOREST,
AND YOU CAN SEE WHAT I MEAN.
YOU WON'T HAVE TO WAIT LONG
TO SEE YOUR FIRST ANOLE.
MAYBE IT'LL BE A BROWN ANOLE
WITH LONG LEGS
ON THE TRUNK OF A TREE.
HIGHER IN THE TREE,
YOU MIGHT FIND A GREEN ANOLE
WITH SHORTER LEGS
CLIMBING IN THE LEAVES
AND BRANCHES.
AND DOWN BY YOUR FEET, AN ANOLE
WITH A LONG TAIL AND STRIPES
THAT DISAPPEARS INTO THE GRASS
IF YOU GET TOO CLOSE.
HIGH IN THE CANOPY,
IF YOU'RE LUCKY,
YOU MIGHT SEE
A MASSIVE GREEN ANOLE
WITH STRONG JAWS
AND HUGE TOE PADS.
AND IF YOU SIT REALLY STILL,
YOU COULD SPOT A TINY ANOLE
WITH A SHORT TAIL
AND STUBBY LEGS
CLINGING TO THE SMALLEST TWIGS
IN THE FOREST.
ALL OF THESE ANOLES
LIVE SIDE BY SIDE
HERE IN PUERTO RICO,
BUT THEY AREN'T JUST
RANDOMLY SCATTERED ALL OVER.
THEY SPECIALIZE,
SO YOU TEND TO FIND EACH TYPE
IN A DIFFERENT PART
OF THE FOREST.
SOME LOW, SOME HIGH.
SOME ON THE TREE TRUNKS
AND OTHERS
OUT ON THE SMALLEST TWIGS.
HOP OVER TO A SECOND ISLAND,
AND THE PATTERN BECOMES CLEARER.
HERE IN THE DOMINICAN REPUBLIC,
THE ANOLE SPECIES ARE DIFFERENT
THAN THE ONES IN PUERTO RICO,
BUT LOOK AROUND,
AND IT'LL FEEL LIKE DEJA VU.
YOU'LL FIND ANOLES
IN ALL THE SAME PLACES
YOU SAW THEM IN PUERTO RICO--
LONG-LEGGED BROWN ANOLES
ON THE TREE TRUNKS,
ANOLES WITH LONG TAILS
AND STRIPES IN THE GRASSES,
GIANT GREEN ANOLES
IN THE CANOPY, AND SO ON.
THE SPECIES PLAYING THESE ROLES
ARE DIFFERENT,
BUT THEY LOOK STRIKINGLY SIMILAR
BETWEEN ISLANDS.
IT'S ALMOST AS IF DIFFERENT
LOOK-ALIKE ACTORS
WERE PERFORMING THE SAME SHOW.
ACROSS THE CARIBBEAN,
ANOLES THAT LIVE
IN THE SAME PART OF THE FOREST
SHARE SIMILAR
ANATOMICAL FEATURES,
NO MATTER WHICH ISLAND
THEY INHABIT.
IT'S SUCH AN UNUSUAL PATTERN
THAT ANOLE RESEARCHERS
INVENTED A WORD TO DESCRIBE IT.
THEY CALLED THESE ANOLE TYPES
THAT REPEAT FROM ISLAND
TO ISLAND "ECOMORPHS."
Jonathan:
THE ECOMORPHS ARE NAMED
FOR WHERE IN THE ENVIRONMENT
YOU USUALLY FIND THEM--
TRUNK GROUND,
TRUNK,
TRUNK CROWN,
THE CROWN GIANT,
TWIG,
AND GRASS BUSH.
Neil: CUBA, HISPANIOLA,
JAMAICA, AND PUERTO RICO
EACH HAVE DIFFERENT SPECIES,
BUT THEY ALL HAVE
THE SAME ECOMORPHS.
THE QUESTION IS, WHY DO LIZARDS
LIVING IN THE SAME HABITAT
BUT ON DIFFERENT ISLANDS
LOOK SO SIMILAR?
Jonathan: WHY DO THE ONES
NEAR THE GROUND HAVE LONG LEGS
AND THE ONES UP IN THE TREES
HAVE SHORT LEGS?
WHY UP IN THE TREE
DO THEY HAVE BIG TOE PADS
AND THEY'RE OFTEN GREEN
AND THE ONES DOWN ON THE GROUND
HAVE SMALLER TOES PADS
AND ARE BROWN IN COLOR?
Nate: JONATHAN SUSPECTED
THAT EACH ECOMORPH'S
ANATOMICAL FEATURES
HELPED IT SURVIVE
IN A PARTICULAR PART
OF THE FOREST.
HE HATCHED AN INGENIOUS PLAN
TO PUT THIS IDEA TO THE TEST.
Jonathan: THE WAY WE TEST THAT
IS BASICALLY BY HAVING
THE LIZARD OLYMPICS.
Nate: JONATHAN CAPTURED
15 DIFFERENT ANOLE SPECIES
IN PUERTO RICO AND JAMAICA,
AND HE BROUGHT THEM INTO THE LAB
TO MEASURE
THEIR SPRINTING SPEED,
JUMPING ABILITY,
AND TOE PAD CLINGING POWER.
THE SPECIES THAT LIVE
HIGH IN THE TREES,
THE TRUNK CROWNS
AND CROWN GIANTS,
HAVE THE BIGGEST TOE PADS.
THESE TOE PADS HELP THEM STICK
TO SMOOTH SURFACES LIKE LEAVES
SO THEY DON'T
FALL OUT OF THE TREES.
TRUNK GROUND ANOLES
HAVE LONG LEGS,
WHICH HELP THEM JUMP FAR
AND RUN FAST ON FLAT SURFACES.
THESE ARE CRITICAL SKILLS
FOR A LIZARD
THAT HAS TO CAPTURE PREY AND
ESCAPE PREDATORS ON THE GROUND.
JONATHAN'S LIZARD OLYMPICS
CONFIRMED WHAT HE SUSPECTED,
THAT EACH ECOMORPH
HAS ADAPTATIONS
THAT HELP IT MOVE THROUGH
A DIFFERENT PART OF THE FOREST.
Jonathan: WE DID FIND
ONE INTERESTING TWIST
WE DIDN'T EXPECT.
WE THOUGHT THAT LIZARDS
WITH SHORT LEGS
WOULD BE FASTER
ON NARROW SURFACES.
TURNS OUT
THEY'RE NOT FASTER AT ALL.
Nate: THEY MAY NOT BE FAST,
BUT THE SHORT-LEGGED ANOLES
OF THE TWIG ECOMORPH
DO HAVE AN ADVANTAGE
ON THIN BRANCHES.
THEY HARDLY EVER FALL.
IN CONTRAST, LONG-LEGGED ANOLES
HAVE REAL TROUBLE
MANEUVERING ON TWIGS.
Jonathan: THEY REACH AROUND
TO GET THE TWIG,
AND SOMETIMES THEY JUST MISS,
AND THEY JUST FALL OFF THE TWIG.
Nate: FOR AN ANOLE,
BEING ABLE TO MOVE QUICKLY AND
CONFIDENTLY THROUGH THE FOREST
MIGHT MEAN THE DIFFERENCE
BETWEEN A FULL BELLY
AND AN EMPTY ONE,
OR EVEN BETWEEN LIFE AND DEATH.
Neil: IMAGINE AN ANOLE SPECIES
LIVING DOWN NEAR THE GROUND.
JUST BY CHANCE, SOME HAVE GENES
THAT GIVE THEM LONGER LEGS
THAN OTHERS.
THESE LONG-LEGGED LIZARDS
CAN RUN FAST,
SO THEY'RE GREAT
AT CATCHING PREY
AND ESCAPING PREDATORS
ON THE GROUND.
ON AVERAGE,
THESE LONG-LEGGED ANOLES
WILL PRODUCE MORE OFFSPRING
THAN SHORT-LEGGED ANOLES,
PASSING MORE OF THEIR GENES
ON TO THE NEXT GENERATION,
SO OVER MANY GENERATIONS,
THE WHOLE SPECIES
WILL EVOLVE LONGER LEGS.
THAT'S EXACTLY
HOW CHARLES DARWIN ENVISIONED
THE PROCESS
OF NATURAL SELECTION,
SO TO JONATHAN,
NATURAL SELECTION
IN DIFFERENT PARTS OF THE FOREST
COULD EXPLAIN WHY EACH ECOMORPH
EVOLVED ITS DISTINCTIVE TRAITS.
THE PROBLEM WAS, NO ONE WAS
THERE TO SEE EVOLUTION HAPPEN.
Jonathan: I ALWAYS COMPARE
STUDYING EVOLUTION
TO BEING LIKE A DETECTIVE STORY.
WE'VE GOT A WHODUNIT.
WHAT HAPPENED IN THE PAST?
WHY DID IT HAPPEN?
WE CAN'T GO BACK IN TIME,
SO WE HAVE TO USE
WHATEVER CLUES WE HAVE
TO PIECE IT ALL TOGETHER
TO FIGURE OUT
WHAT HAPPENED IN THE PAST.
Neil: SINCE EACH ISLAND
HAS DIFFERENT SPECIES
BUT THE SAME ECOMORPHS,
THE BIG QUESTION IS WHETHER
THESE ECOMORPHS EVOLVED ONCE
AND THEN SPREAD
TO THE DIFFERENT ISLANDS
OR EVOLVED SEPARATELY
ON EACH ISLAND.
Jonathan: TO DISTINGUISH
BETWEEN THESE POSSIBILITIES,
WE NEED TO RECONSTRUCT
THE EVOLUTIONARY HISTORY
OF ANOLES IN THE CARIBBEAN.
AN EVOLUTIONARY TREE
IS A DIAGRAM THAT ILLUSTRATES
THE EVOLUTIONARY RELATIONSHIPS
OF A SPECIES.
Neil: LIKE A REAL TREE,
AN EVOLUTIONARY TREE BEGINS
AS A SINGLE STEM,
A SINGLE ANCESTOR SPECIES.
WHEN THAT ONE SPECIES SPLITS
INTO TWO, THE STEM BRANCHES.
AS THE TREE GROWS, SOME BRANCHES
DIE BACK AS SPECIES GO EXTINCT,
BUT OTHERS KEEP GROWING
AND BRANCHING.
FOR A GROUP LIKE ANOLES,
WITH HUNDREDS OF LIVING SPECIES,
FIGURING OUT THE EVOLUTIONARY
TREE IS A DAUNTING TASK.
ONE TYPE OF EVIDENCE
THAT HELPS SCIENTISTS
BUILD EVOLUTIONARY TREES
IS SOMETHING YOU CAN FIND
INSIDE EVERY PLANT AND ANIMAL
ON EARTH--DNA.
Jonathan: DNA CHANGES OVER TIME.
IT EVOLVES.
THE LONGER TWO SPECIES
HAVE BEEN DIVERGING SEPARATELY,
THE GREATER THE DIFFERENCE
WILL BE IN THEIR DNA,
AND SO BY SEQUENCING THE DNA
OF MANY SPECIES,
YOU CAN BUILD
AN EVOLUTIONARY TREE.
Neil: THE SHAPE OF THAT TREE,
ITS PATTERN OF BRANCHING,
CAN HELP US UNDERSTAND
HOW ANOLES EVOLVED
AND SPREAD ACROSS ISLANDS.
AT ONE EXTREME,
ALL THE ECOMORPHS
COULD HAVE EVOLVED JUST ONCE,
THEN SPREAD
FROM ISLAND TO ISLAND.
AT THE OTHER EXTREME,
ANOLES COULD HAVE SPREAD
TO DIFFERENT ISLANDS FIRST,
AND THEN EVOLVED
INTO THE ECOMORPHS SEPARATELY
ON EACH OF THE FOUR ISLANDS.
Nate: JONATHAN AND HIS
COLLEAGUES COLLECTED DNA SAMPLES
FROM 55 SPECIES OF ANOLES
TO BUILD AN EVOLUTIONARY TREE
THAT ENCOMPASSED EVERY ECOMORPH
ON ALL FOUR ISLANDS.
Jonathan: HAD THE ECOMORPHS
TRULY EVOLVED INDEPENDENTLY
ON DIFFERENT ISLANDS?
WELL, THE DNA SHOULD TELL US.
Nate: THE TREE GAVE THEM
AN ASTONISHING ANSWER.
DESPITE ALL THE VARIATION
AMONG THEM,
ANOLES LIVING ON THE SAME ISLAND
WERE MORE CLOSELY RELATED
TO EACH OTHER
THAN TO SPECIES
ON OTHER ISLANDS,
EVEN THE ONES
THAT LOOKED STRIKINGLY SIMILAR.
THIS MEANT THAT ANOLES
HAD COLONIZED
THE DIFFERENT ISLANDS FIRST
AND THEN EVOLVED ON EACH ISLAND
INTO A VIRTUALLY IDENTICAL
COMMUNITY OF ECOMORPHS.
Jonathan: NO ONE COULD EVER
ARGUE ABOUT THAT AGAIN.
THEY EVOLVED INDEPENDENTLY
ON EACH ISLAND.
Nate: THESE SCIENTISTS
HAD REVEALED
ANOTHER LAW OF THE LIZARD--
WHEN THEY LIVE
IN THE SAME TYPE OF ENVIRONMENT,
DIFFERENT SPECIES EVOLVE
SIMILAR TRAITS TO SURVIVE
AGAIN AND AGAIN AND AGAIN.
Jonathan: WELL,
PEOPLE WERE VERY EXCITED
WHEN THIS RESULT CAME OUT
BECAUSE IT SHOWED THAT
EVOLUTION DOES REPEAT ITSELF,
THAT THERE ARE RULES
TO EVOLUTION.
Nate: MANY SCIENTISTS THOUGHT
THAT NATURE WAS SO COMPLEX
AND EVOLUTION UNFOLDED
OVER SUCH LONG TIMESCALES
THAT YOU'D RARELY SEE
THE SAME OUTCOME TWICE.
Jonathan: THEY SUGGESTED
THAT IF YOU COULD SOMEHOW
REPLAY THE TAPE OF LIFE,
YOU WOULD GET
A DIFFERENT OUTCOME EVERY TIME.
BUT HERE YOU GOT THE SAME
OUTCOME FOUR TIMES IN A ROW
ON DIFFERENT ISLANDS.
Nate: JONATHAN DECIDED TO DIG
DEEPER INTO THIS INTRIGUING IDEA
THAT EVOLUTION WAS PREDICTABLE.
Jonathan: IT WOULD BE GREAT
TO ACTUALLY DO AN EXPERIMENT
TO TEST THE HYPOTHESIS
THAT NATURAL SELECTION DRIVES
THE EVOLUTION OF THESE FEATURES.
Nate: JONATHAN WAS
ABOUT TO VENTURE
INTO NEW SCIENTIFIC TERRITORY
AND DISCOVER SOMETHING
THAT DARWIN
NEVER WOULD HAVE IMAGINED.
Jonathan:
IT'S A LITTLE-KNOWN FACT
THAT CHARLES DARWIN
WAS A GREAT EXPERIMENTER,
BUT HE NEVER DID AN EXPERIMENT
ABOUT HIS MOST IMPORTANT IDEA--
THE THEORY OF EVOLUTION
BY NATURAL SELECTION.
AND THE REASON HE DIDN'T DO
AN EXPERIMENT IS OBVIOUS.
HE THOUGHT THAT EVOLUTION
MOVED INCREDIBLY SLOWLY,
GLACIALLY SLOWLY.
HE THOUGHT IT WOULD TAKE
THOUSANDS OF YEARS
TO LEAD TO CHANGES
THAT WE COULD DETECT.
WELL, DARWIN WAS RIGHT ABOUT
AN AMAZING NUMBER OF HIS IDEAS,
BUT THIS IS ONE IDEA
ABOUT WHICH HE WAS WRONG.
Neil: IT TURNS OUT THAT ANOLES
CAN SHOW US SOMETHING
THAT DARWIN
NEVER COULD HAVE IMAGINED--
WHAT EVOLUTION LOOKS LIKE
AS IT'S HAPPENING.
TO SEE IT FOR OURSELVES,
WE'RE HEADING TO THE BAHAMAS.
ON THE FOUR BIGGEST ISLANDS
OF THE CARIBBEAN,
ANOLES HAVE EVOLVED TO THRIVE IN
DIFFERENT PARTS OF THE FOREST,
AND THEIR DNA REVEALS
THAT THEY DID SO INDEPENDENTLY
ON EACH ISLAND.
THESE EVENTS
TOOK MILLIONS OF YEARS,
BUT WHAT IF YOU COULD WATCH
EVOLUTION HAPPEN?
CHARLES DARWIN
THOUGHT THAT THE EARTH
CHANGED GRADUALLY OVER EONS,
AND SINCE PLANTS AND ANIMALS
ADAPT TO THEIR ENVIRONMENTS,
HE THOUGHT
THE PROCESS OF EVOLUTION
HAD TO BE SLOW AS WELL.
BUT SOME ENVIRONMENTS
ARE MUCH MORE DYNAMIC
THAN DARWIN IMAGINED.
THE BAHAMAS
HAVE HUNDREDS OF TINY ISLANDS
THAT OFTEN GET HIT
BY HURRICANES.
HERE, SPECIES COLONIZE AND
GO EXTINCT FROM YEAR TO YEAR.
THAT MAKES THEM
THE PERFECT LABORATORY
TO STUDY
SURVIVAL AND ADAPTATION,
AND THAT'S WHAT BROUGHT
ECOLOGIST ROB PRINGLE HERE.
Rob Pringle: YOU KNOW, IF YOU DO
YOUR BEST MALE LIZARD
IMPERSONATION,
YOU MIGHT GET THE FEMALES
TO COME CHECK YOU OUT.
Neil: OH, YEAH, SHOULD I GET
DOWN AND DO SOME PUSH-UPS?
I WAS HELPING ROB CATCH ANOLES
FOR A MASSIVE EXPERIMENT
ON ANOLE EVOLUTION.
Rob: EASIEST AND BEST WAY TO
CATCH AN ANOLE IS TO NOOSE IT,
WHICH IS BASICALLY, IT'S LAND
FISHING FOR LIZARDS, YOU KNOW?
SO, YOU TAKE A FISHING POLE,
AND YOU TIE A LITTLE SLIPKNOT
AT THE END OF IT,
AND YOU TRY TO LOOP THAT
AROUND THE HEAD OF A LIZARD,
AND THEN YOU PULL,
AND HOPEFULLY YOU HAVE A LIZARD
ON THE END OF YOUR STICK.
♪
Neil: OH, LOOK AT THIS GUY!
Nate: YOU HAVE TO BRING IT UP
TO YOUR FACE.
Neil: OH!
Nate: OH [BLEEP]
YOU ALL RIGHT?
WELL, I GOTTA SAY THAT WAS THE
WORST LIZARD CATCH IN HISTORY!
Neil: SO, I GOT THE LIZARD.
AND I ALSO FELL THIGH-DEEP
INTO A HOLE IN THE LIMESTONE.
BUT ME AND THE LIZARD ARE OKAY.
Rob: OH, THERE WE GO.
Neil: I'LL LEAVE IT TO
THE PROFESSIONALS FROM NOW ON.
Rob: WELL, YOU KNOW.
Neil: ROB AND HIS COLLEAGUES
BRING THE ANOLES
BACK TO THEIR PORTABLE LAB
TO SAMPLE THEIR DNA
AND TAKE X-RAYS
TO MEASURE THE LIZARDS' BONES
WITH PRECISION.
THEY'RE LOOKING FOR SIGNS
OF EVOLUTION
TAKING PLACE NOT OVER MILLENNIA,
BUT DURING AN EXPERIMENT
LASTING JUST A FEW YEARS.
AFTER YOU X-RAY HER
AND TAKE HER MEASUREMENTS,
THEN SHE'S GOING TO COME
RIGHT BACK TO THIS SAME PERCH?
Rob: THAT'S EXACTLY RIGHT.
Neil:
SHE'LL PROBABLY JUST THINK
IT WAS A REALLY WEIRD DREAM.
Rob: IT'LL JUST BE
A WEIRD DREAM,
SOMETHING SHE'LL TELL
HER FRIENDS ABOUT.
LIKE, "YOU GUYS WOULDN'T BELIEVE
WHAT HAPPENED TO ME,"
AND THEN NONE OF THEM
WILL BELIEVE HER.
Nate: ANOLE RESEARCHERS
HAVE BEEN COMING
TO THE BAHAMAS FOR DECADES
BECAUSE IT'S A PERFECT PLACE
TO STUDY LIZARD EVOLUTION.
Jonathan:
IF YOU GET A SMALL ENOUGH ISLAND
THAT YOU CAN STUDY
THE WHOLE POPULATION
AND YET BIG ENOUGH
THAT THEY CAN SURVIVE AND ADAPT,
IT'S ALMOST THE EQUIVALENT
OF A LABORATORY TEST TUBE.
Nate: IN THE 1970s,
ECOLOGIST TOM SCHOENER FOUND
SMALL ISLANDS WITHOUT ANOLES,
AND HE ADDED ANOLES TO STUDY
HOW POPULATIONS GROW, SHRINK,
AND EVENTUALLY GO EXTINCT.
SOME POPULATIONS DEFIED THE ODDS
AND CONTINUED TO THRIVE
YEAR AFTER YEAR.
THESE SURVIVORS GAVE JONATHAN
AN INTRIGUING IDEA.
WOULD THE LIZARDS ADAPT
TO THEIR NEW ISLAND HOMES?
Jonathan: THEY HAD INADVERTENTLY
SET UP AN EVOLUTION EXPERIMENT
BECAUSE THESE ISLANDS DIFFERED
IN THEIR CHARACTERISTICS.
TOM SCHOENER
HAD MOVED BROWN ANOLES
FROM A LARGER ISLAND,
STANIEL CAY,
WHERE THE LIZARDS LIVED
ON LARGE TREES,
TO THESE TINY LITTLE ISLANDS
THAT DIDN'T HAVE TREES.
THEY HAD NARROW BUSHES AND,
AND NARROW-STEMMED VEGETATION.
JUST LIKE TWIG ANOLES HAVING
SHORT LEGS ON NARROW VEGETATION,
WE PREDICTED
THAT THE BROWN ANOLES,
WHEN MOVED FROM A BROAD SURFACE
TO A NARROW SURFACE,
WOULD EVOLVE SHORTER LEGS.
Nate: DID THE SAME RULES
THAT MADE EVOLUTION PREDICTABLE
ON THE LARGE ISLANDS
OPERATE IN THE BAHAMAS, TOO?
AND IF SO, COULD WE WITNESS
EVOLUTION HAPPEN
IN JUST 14 YEARS?
FEW BIOLOGISTS
WOULD HAVE ASKED THIS QUESTION
BECAUSE MOST OF THEM
STILL THOUGHT
THAT ANIMALS EVOLVED TOO SLOWLY
TO OBSERVE IN A HUMAN LIFETIME,
BUT JONATHAN SAW AN OPPORTUNITY
TO PUT THIS CONVENTIONAL WISDOM
TO THE TEST.
Shane Campbell-Staton:
A BIG PART OF BIOLOGY
IS ABOUT CREATIVITY, RIGHT?
AND ABOUT UNDERSTANDING, LIKE,
WHAT IS THE RIGHT QUESTION?
THERE'S AN ARTISTRY THERE.
AND IF THAT'S AN ART,
THEN JONATHAN IS A PICASSO.
Nate: JONATHAN RETURNED
TO TOM SCHOENER'S ISLANDS
IN THE 1990s WITH A NEW PLAN--
TO COMPARE THE ANATOMY
OF THE NEW ISLAND POPULATIONS
AND THE ORIGINAL
SOURCE POPULATION.
IF THE ANOLES WERE DIFFERENT,
THAT WOULD SHOW
THAT THESE POPULATIONS
HAD EVOLVED IN JUST 14 YEARS.
Jonathan: AND THE RESULTS
FLASHED ON THE SCREEN.
THE POPULATIONS WERE DIFFERENT.
THEY HAD EVOLVED!
WELL, NEEDLESS TO SAY,
THIS WAS INCREDIBLY EXCITING.
Nate: THE ANOLES DIFFERED IN
JUST THE WAY JONATHAN EXPECTED.
ON THE ISLANDS
WITH SLENDER BRANCHES,
THE ANOLES
HAD EVOLVED SHORTER LEGS,
AND THEY DID SO
IN JUST 14 YEARS.
EVEN FOR ANOLES, WHICH CAN
REPRODUCE AT ONE YEAR OLD,
14 YEARS IS INCREDIBLY FAST.
Jonathan: OF COURSE, DARWIN
WOULD HAVE BEEN VERY SURPRISED.
HE THOUGHT THAT EVOLUTION
OCCURRED SO SLOWLY
THAT YOU COULDN'T
POSSIBLY SEE IT
UNTIL A THOUSAND YEARS
HAD ELAPSED.
ONCE WE REALIZED THAT ANOLES
WOULD ADAPT RAPIDLY
TO NEW CONDITIONS,
THAT OPENED OUR EYES TO OTHER
EXPERIMENTS WE COULD DO.
Nate: ANOLE RESEARCHERS
COULD NOW ASK NEW QUESTIONS,
LIKE HOW DO PREDATORS
AFFECT EVOLUTION?
AND THEY COULD ANSWER
THOSE QUESTIONS
NOT JUST BY DOING DETECTIVE WORK
ABOUT THE ANCIENT PAST,
BUT BY DOING EXPERIMENTS
AND WATCHING EVOLUTION UNFOLD
IN THE PRESENT.
THAT'S WHAT ROB PRINGLE
AND JASON KOLBE
ARE DOING IN THE BAHAMAS
RIGHT NOW.
Rob: SO, IT'S A,
IT'S A GOOD PLACE TO BE
IF YOU'RE A, A BROWN ANOLE.
Nate: LET'S GO PAINT
SOME LIZARDS!
Rob: LET'S GO
PAINT SOME LIZARDS!
Nate: ALL RIGHT!
ROB SHOWED ME HOW TO MARK ANOLES
WITH NON-TOXIC, WATER-SOLUBLE
PAINT FOR HIS EXPERIMENT.
Rob: YEAH, THERE'S A TON
OF LIZARDS ON THIS ISLAND.
Nate: THIS IS ALSO FUN.
Rob: YEAH, IT'S A LOT OF FUN!
Nate: IT'S LIKE SHOOTIN'
LIZARDS IN A BARREL.
Rob: SHOOTIN' LIZARDS
IN A TREE.
Nate: YES, IT'S KIND OF
EXACTLY LIKE THAT.
[LAUGHTER]
THE LIZARDS
WILL LOSE THESE PAINT MARKS
THE NEXT TIME
THEY SHED THEIR SKINS,
BUT THE PAINT DOESN'T NEED
TO LAST LONG.
BY MARKING ALL THE ANOLES
WE CAN FIND ONE DAY
AND RETURNING TO COUNT
THE MARKED AND UNMARKED ANOLES
THE NEXT DAY,
WE CAN ESTIMATE THE TOTAL NUMBER
OF ANOLES ON AN ISLAND.
Rob: LAST YEAR
WE HAD UPWARDS OF 400 LIZARDS
ON THIS ISLAND.
Nate: THIS POPULATION CENSUS
HELPS THE RESEARCHERS MONITOR
HOW THE ANOLES ARE DOING
ON DIFFERENT ISLANDS.
AND ON SOME ISLANDS,
THE ANOLES ARE IN REAL DANGER
BECAUSE ROB AND JASON HAVE ADDED
ANOTHER LIZARD INTO THE MIX,
ONE OF THE BROWN ANOLE'S
ENEMIES--
THE CURLY-TAILED LIZARD.
♪
♪
Neil: IT TURNS OUT
THAT CURLY-TAILED LIZARDS
DON'T JUST IMPACT THE NUMBERS
OF ANOLES ON ISLANDS.
THEY ACTUALLY CAUSE
NATURAL SELECTION.
Jason Kolbe:
WITHIN THE FIRST SIX MONTHS
OF THE CURLY TAILS BEING THERE,
ANOLES WITH LONGER HIND LIMBS
HAVE BETTER SURVIVAL,
AND PRESUMABLY
THAT'S BECAUSE THEY'RE FASTER
AT RUNNING ON THE GROUND
TO ESCAPE PREDATION
FROM THE CURLY-TAILED LIZARD.
Neil: GRADUALLY,
THE ANOLES BEGIN TO MOVE UP.
THEY SPEND LESS TIME
ON THE GROUND
AND MORE TIME
IN THE SLENDER BRANCHES.
ONCE THEY'RE OUT OF DANGER
FROM THE PREDATOR,
NATURAL SELECTION
HAS A DIFFERENT EFFECT.
Jason: DURING THAT PERIOD,
SELECTION REVERSES
AND FAVORS BROWN ANOLES
WITH SHORTER HIND LIMBS
BECAUSE THEY'RE OCCUPYING
THESE NARROWER BRANCHES,
AND ANOLES WITH SHORTER LIMBS
CAN MOVE BETTER
IN THAT ENVIRONMENT.
Neil: THESE EXPERIMENTS REVEAL
ANOTHER LAW OF THE LIZARD--
NATURAL SELECTION
IS HAPPENING ALL THE TIME,
AND IT'S DRIVEN
NOT ONLY BY THE ENVIRONMENT,
BUT ALSO BY OTHER SPECIES.
ONE SPECIES MORE THAN ANY OTHER
IS SHAPING THE NEXT ERA
OF LIZARD EVOLUTION.
HOW ARE ANOLES ADAPTING
TO THE AGE OF HUMANS?
TO FIND OUT, NATE AND I ARE
HEADING TO MY BACKYARD, MIAMI,
TO DISCOVER
THE ASTONISHING ADAPTATIONS
OF THESE LITTLE LIZARDS
IN THE BIG CITY.
Nate: OUR JOURNEY
HAS ALREADY SHOWN US
THAT ANOLES ARE EVOLVING
TO SURVIVE IN A CHANGING WORLD,
BUT NEVER IN THEIR HISTORY
HAVE ANOLES FACED
A MORE PERILOUS
OR UNCERTAIN ENVIRONMENT
THAN THE WORLD OF HUMANS.
Neil: LIVING IN MIAMI, I SEE
ANOLES AROUND ME EVERY DAY,
BUT A LOT OF THE ANOLES
I SEE IN MIAMI
DIDN'T ACTUALLY ORIGINATE THERE.
THEY COME FROM ISLANDS
ALL OVER THE CARIBBEAN.
Nate: SOUTHERN FLORIDA IS A
MELTING POT OF ANOLE IMMIGRANTS.
FLORIDA HAS ONLY ONE
NATIVE SPECIES OF ANOLE,
BUT EIGHT OTHER SPECIES HAVE
ESTABLISHED POPULATIONS HERE.
Neil: THEY GOT TO MIAMI EITHER
THROUGH THE PET TRADE
OR ACCIDENTALLY IN SHIPMENTS
OF PRODUCE AND OTHER GOODS
COMING FROM THE CARIBBEAN.
Nate: HUMANS DON'T JUST BRING
ANOLES INTO THE CITY.
AS WE CONVERT WILD FORESTS
INTO CONCRETE JUNGLES,
WE ALSO BRING THE CITY
TO ANOLES.
Jason: WHEN ANOLES ARRIVE
IN A NEW AREA,
THEY ENCOUNTER
NOVEL TYPES OF ENVIRONMENTS,
AND SO THERE ARE NEW PREDATORS,
THERE ARE NEW COMPETITORS.
MOST ANOLES LIVE
ON THE TRUNKS OF TREES,
BRANCHES OF TREES,
HIGHER UP IN THE CANOPY.
BUT IN THE URBAN ENVIRONMENT,
MUCH OF THIS VEGETATION
HAS BEEN REPLACED BY BUILDINGS
AND WALLS, LAMPPOSTS.
Nate: THOSE SURFACES CAN BE
SMOOTHER AND HARDER TO CLIMB
THAN TREES AND ROCKS,
AND THAT'S NOT
THE ONLY CHALLENGE OF CITY LIFE.
Jason: BY REPLACING
NATURAL VEGETATION
WITH CONCRETE, ASPHALT, THEY
CHANGE THE THERMAL ENVIRONMENT.
THEY'RE MUCH HOTTER
THAN A COMPARABLE NATURAL AREA.
Nate: SINCE LIZARDS
CAN'T REGULATE
THEIR BODY TEMPERATURES
INTERNALLY,
THE HEAT OF THE CITY COULD ALSO
THREATEN THEIR SURVIVAL.
Jonathan: IN SOME CASES, THE
CHALLENGES ARE TOO OVERWHELMING.
THEY JUST CAN'T DO IT,
BUT SOMETIMES
THEY'RE ABLE TO SURVIVE
AND PERHAPS EVEN ADAPT
TO THESE NEW CONDITIONS.
Neil: ONE OF THESE SURVIVORS IS
THE PUERTO RICAN CRESTED ANOLE,
WHICH THRIVES IN CITIES
THROUGHOUT PUERTO RICO.
RESEARCHERS KRISTIN WINCHELL
AND SHANE CAMPBELL-STATON
WANT TO UNDERSTAND
HOW THIS SPECIES
IS COPING WITH LIFE IN THE CITY.
Kristin Winchell:
THE OVERARCHING QUESTION
MY RESEARCH
IS TRYING TO TACKLE IS
CAN HUMANS INFLUENCE
THE COURSE OF EVOLUTION?
Shane: HOW FAST
CAN THESE ANIMALS CHANGE?
AND CAN THEY KEEP PACE
WITH HUMAN-MEDIATED CHANGES
IN THE ENVIRONMENT?
Kristin: I THINK
A LOT OF PEOPLE DO GET CONFUSED
WHEN I'M WALKING AROUND
IN URBAN AREAS.
I AM WALKING AROUND
WITH A FISHING POLE,
WHICH IS VERY STRANGE.
I'M STICKING MY FISHING POLE
UP TREES AND ON THEIR WALLS,
WHICH IS EVEN STRANGER,
AND SO WE,
WE GET A LOT OF QUESTIONS.
Neil: TO UNDERSTAND
WHETHER LIZARDS
ARE ADAPTING TO CITY LIFE,
KRISTIN AND SHANE COLLECT ANOLES
FROM URBAN AND NATURAL SITES
AND TAKE THEM
BACK TO THEIR FIELD LAB
TO COMPARE THEIR ANATOMY
AND PHYSICAL PERFORMANCE.
KRISTIN FOUND THAT,
COMPARED TO FOREST LIZARDS,
URBAN LIZARDS HAD LONGER LEGS
AND LARGER TOE PADS.
THE QUESTION IS, DO THESE TRAITS
MAKE A DIFFERENCE?
TO FIND OUT, KRISTIN PLANNED
A NEW LIZARD OLYMPICS
TO TEST THE ANOLES' PERFORMANCE
IN THE URBAN ENVIRONMENT.
THE FIRST EVENT
IN THIS COMPETITION?
URBAN AND FOREST LIZARDS
SPRINTED ON RACETRACKS
WITH THREE DIFFERENT SURFACES.
Kristin: WE'RE RUNNING THEM
ON PAINTED CONCRETE,
ON BARK, AND ON UNPAINTED METAL,
AND SO WE'RE
VERY INTERESTED TO SEE
IF THE FOREST LIZARDS CAN RUN
AS FAST AS THE URBAN LIZARDS
ON THESE OTHER SUBSTRATES.
Neil: WHILE KRISTIN'S LIZARDS
SPRINTED
ON MINIATURE RACETRACKS,
SHANE SET UP
A LESS TRADITIONAL OLYMPIC EVENT
TO TEST HOW URBAN ANOLES COPE
WITH THE HEAT OF THE CITY.
Shane: REPTILES
ARE COLD-BLOODED ANIMALS,
AND A LOT OF ASPECTS
OF THEIR BIOLOGY
ARE LINKED TO TEMPERATURE.
TO FIGURE OUT HOW HOT A LIZARD
CAN GET BEFORE IT STOPS WORKING,
WE GRADUALLY WARM THAT LIZARD,
AND WE PERIODICALLY FLIP IT
ONTO ITS BACK.
Neil: SHANE ISN'T HURTING
THE LIZARDS.
AS HE SLOWLY HEATS THEM UP,
THEY EVENTUALLY GET TOO HOT
TO RESPOND.
Shane: THE RIGHTING REFLEX
IS SUCH A GOOD TEST
BECAUSE A LIZARD ALWAYS
WANTS TO BE ON ITS FEET.
Neil: SHANE RECORDS
THE TEMPERATURE
AT WHICH THEY CAN NO LONGER
TURN THEMSELVES BACK OVER,
AND THEN HE QUICKLY HELPS
THE LIZARDS COOL BACK DOWN.
AFTER CAPTURING AND TESTING
HUNDREDS OF ANOLES,
IT WAS TIME
FOR SHANE AND KRISTIN
TO COMPARE THE LIZARDS
FROM THE FOREST AND THE CITY.
ON AVERAGE, URBAN LIZARDS WERE
ABLE TO TOLERATE TEMPERATURES
THAT WERE
ONE DEGREE CELSIUS HOTTER
COMPARED TO FOREST LIZARDS.
Kristin: A DIFFERENCE
OF ONE DEGREE CELSIUS
MIGHT NOT SEEM LIKE A LOT,
BUT FOR A LIZARD,
THIS IS A DIFFERENCE
OF BEING ABLE TO BE ACTIVE
ALL DAY LONG
AND HAVE ACCESS TO ALL OF
THOSE MATES AND ALL OF THAT FOOD
THAT YOU OTHERWISE
WOULD HAVE TO GIVE UP
BECAUSE YOU'RE HIDING IN
THE SHADE TRYING TO COOL DOWN.
Neil: THE URBAN LIZARDS ALSO
HAVE AN ADVANTAGE RUNNING
ON THE SLICK SURFACES FOUND
IN THE CITY ENVIRONMENT.
Kristin: THE URBAN LIZARDS
RUN FASTER ON ALL SUBSTRATES,
AND THESE DIFFERENCES
ARE MOST PRONOUNCED
ON THE VERY SMOOTH
VERTICAL SUBSTRATES,
ON THE METAL
AND ON THE PAINTED CONCRETE.
THE ABILITY TO PERFORM WELL
ON THESE SUBSTRATES
HAS REAL IMPLICATIONS FOR
THEIR SURVIVAL IN THIS HABITAT.
Neil: THESE LITTLE LIZARDS
CONTINUE TO SURPRISE SCIENTISTS
WITH THEIR POWERS OF ADAPTATION,
EVEN IN FAST-CHANGING
ENVIRONMENTS.
KRISTIN AND SHANE'S DISCOVERIES
SHOW THAT THE ANOLES'
ANCIENT EVOLUTIONARY PLAYBOOK
STILL HELPS THEM SURVIVE AND
ADAPT, EVEN IN THE MODERN WORLD.
Nate: JUST WHEN WE THOUGHT
OUR JOURNEY WAS OVER,
WE HEARD ABOUT A NEW DISCOVERY
IN THE DOMINICAN REPUBLIC--
A NEW ANOLE SPECIES,
A TRULY BIZARRE LIZARD
THAT HAD CAUGHT SCIENTISTS
COMPLETELY OFF GUARD.
WE HAD TO SEE IT.
ONE OF THE FEW PEOPLE
WHO KNEW WHERE TO FIND IT
WAS LUKE MAHLER, THE SCIENTIST
WHO FIRST DESCRIBED IT.
Luke Mahler:
IT'S AN UNEXPECTED DISCOVERY.
THIS IS A GIANT ANOLE THAT,
THAT LIVES HIGH IN THE TREES
BUT IS STRIKINGLY SIMILAR
TO A GROUP OF LIZARDS
PREVIOUSLY ONLY KNOWN FROM CUBA,
SO THIS, THIS ANOLE POTENTIALLY
REPRESENTS A NEW ECOMORPH,
AND SO WE'RE HERE
TO LOOK FOR IT.
Neil: LUKE TOOK US TO THE PLACE
WHERE HE FIRST SAW
THIS MYSTERIOUS ANOLE.
Luke: YOU GET
THIS SORT OF NEAT SPOT
WHERE THE TREES
ARE DRY FOREST TREES,
BUT THEN YOU START GETTING
THE SPANISH MOSS,
LOTS OF LICHEN.
Nate: I'VE NEVER SEEN
ANY PLACE LIKE THIS.
THIS IS A TOTALLY BIZARRE,
UNIQUE, COOL PLACE.
Neil: I'M "LICHEN"
THIS ENVIRONMENT.
Nate: YEAH.
Luke: OH! THAT'S, THAT'S GOOD!
[LAUGHTER]
Nate: "I'M LICHEN
THIS ENVIRONMENT."
Neil: LUKE TOLD US THAT
OUR BEST CHANCE
OF FINDING THESE LIZARDS
WAS TO SEARCH FOR THEM AT NIGHT
WHILE THEY WERE SLEEPING.
Nate: I WILL FLIP OUT
IF WE SEE THIS LIZARD TONIGHT.
Neil: IS THAT A GUARANTEE?
Nate: THAT I'LL FLIP OUT?
Neil: IS THAT A PROMISE?
Nate: I PROMISE.
I'LL FLIP OUT.
Neil: AWESOME.
I CAN'T WAIT.
Nate: THIS NEW SPECIES WAS
ONE OF THE MOST MYSTERIOUS
LIZARDS IN THE WORLD,
AND WE WANTED TO BE
THE FIRST FILM CREW TO FIND IT.
EASIER SAID THAN DONE.
Luke: YOU GOTTA BE
IN THE RIGHT SPOT, GET LUCKY,
AND BE LOOKING
FOR THE RIGHT THING.
Nate: FROM LUKE'S DESCRIPTION,
WE KNEW WHAT TO LOOK FOR--
A GRAYISH MOSSY-LOOKING LIZARD
SLEEPING
ON A GRAY MOSSY BRANCH.
I'VE NEVER SEEN
SO MANY TARANTULAS.
Luke: WELCOME TO MY WORLD.
[LAUGHTER]
[SIGHS]
Nate: AFTER SPENDING FIVE HOURS
LOOKING AT TWIGS IN THE DARK,
YOU START SEEING THINGS
THAT AREN'T THERE.
I'M PRETTY SLEEPY.
IT HAS BEEN A LONG,
UNSUCCESSFUL NIGHT.
Neil: OTHER THAN
A FEW HUNDRED TARANTULAS
AND A TON OF BUG BITES,
WE HAD NOTHING.
Nate: I THINK WE'RE
GOING TO FIND IT,
JUST NOT TONIGHT.
Neil: WE STILL HAD ONE MORE
NIGHT IN THE DOMINICAN REPUBLIC,
ONE LAST CHANCE
TO BE THE FIRST FILM CREW
TO CAPTURE FOOTAGE
OF THIS NEW SPECIES,
BUT IT WAS STARTING TO FEEL
LIKE A LONG SHOT.
♪
Nate: IT WAS OUR LAST NIGHT
IN THIS REMOTE CORNER
OF THE DOMINICAN REPUBLIC,
OUR LAST CHANCE
TO FIND AND FILM A LIZARD
THAT WAS BRAND-NEW TO SCIENCE.
WE WERE ALL A LITTLE NERVOUS.
Luke: SO, THE GOAL HERE
IS IF YOU SEE A LIZARD
AND IT DOESN'T SEE YOU,
LOOK AWAY FROM IT,
DON'T SCARE IT WITH YOUR LIGHTS,
FLAG IT, RADIO OVER,
LET EVERYBODY KNOW.
♪
Neil: A FEW HOURS GO BY, AND
LUKE GETS A CALL OVER THE RADIO.
Man on radio:
SO, WE GOT AN ANOLE UP HERE.
Luke: ALL RIGHT,
I'LL BE RIGHT OVER.
OKAY, WHICH, WHICH, WHICH TREE?
YEP, THAT'S,
THAT'S ANOLIS LANDESTOYI.
OKAY, WE GOT ONE.
Nate: A BABY?
Luke: WE GOT ONE.
Nate: WHERE IS IT?
Luke: I'LL SHOW YOU.
SO, WE'RE GOING TO BE CAREFUL
NOT TO SPOOK IT.
UP. YOU CAN SEE
THERE'S THAT WHITE SPOT.
Nate: OH, YEAH!
Luke: THAT'S IT.
IT'S A LITTLE JUVIE HANGING
HEAD-DOWN WITH ITS TAIL UP.
Nate: HOW DID YOU SEE THAT?
Neil: WHOA!
IT'S TOTALLY DIFFERENT-LOOKING
FROM, THAN EVERYTHING ELSE
WE'VE SEEN.
Nate: FIRST
ANOLIS LANDESTOYI, MAN!
YEAH!
ALL RIGHT!
SEEING THIS LIZARD
FOR THE FIRST TIME WAS AMAZING,
BUT THEN REALITY HIT.
IT WAS DANGLING FROM A BRANCH
30 FEET OFF THE GROUND,
WAY TOO HIGH FOR US TO FILM.
OUR ONLY CHANCE
WAS TO WAIT UNTIL SUNRISE
AND HOPE THAT IT MOVED LOW
ENOUGH THAT WE COULD CATCH IT.
HEY, I GOT AN IDEA.
I GOT A GREAT IDEA.
LET'S PULL THE CAR OVER HERE
AND NOOSE HIM
FROM ON TOP OF THE CAR.
Neil: WE BOTH GET ON THE ROOF.
NATE'S LOOKING THROUGH THE
CAMERA SO THAT HE CAN GUIDE ME,
BECAUSE I CAN'T SEE
WHAT I'M DOING.
Nate: NO, I THINK
YOU JUST LOST HIM.
YES, YES, YES, YES, YES!
OH! YOU GOT HIM!
[BLEEP] YOU GOT HIM!
YES!
[LAUGHS]
NEIL!
HANDS DOWN,
THE BEST LIZARD CATCH
THAT I'VE EVER SEEN.
Neil: HERE IS ONE OF THE RAREST
ANOLES IN THE WORLD!
[LAUGHTER]
OH, HE'S LIKE A LITTLE DINOSAUR.
Nate: WHAT?
Neil: HE'S TRYING
TO BITE ME HERE.
Nate: OH, MY GOD!
Neil: I'M PRETTY STOKED.
Nate: THIS IS LIKE
THE WHOLE TRIP,
WE'VE BEEN LOOKING
FOR THIS GUY.
VERY, VERY FEW PEOPLE
WHO ARE INTERESTED IN ANOLES
HAVE SEEN THIS LIZARD,
WHICH MAKES IT SUPER SPECIAL
TO GET TO, TO GET TO HOLD.
AS WE HELD THIS NEW SPECIES
AND FILMED IT
CLIMB BACK INTO THE TREE,
WE COULDN'T HELP BUT REMEMBER
THE FIRST LAW OF THE LIZARD
WE LEARNED ON THIS JOURNEY--
EXPECT SURPRISES.
EVEN ON HISPANIOLA,
AN ISLAND WHERE BIOLOGISTS
HAVE WORKED FOR DECADES,
HERE WAS A STRANGE ANOLE,
TOTALLY UNLIKE
ANYTHING ELSE ON THE ISLAND,
THAT NO ONE HAD EVEN NOTICED
UNTIL A FEW YEARS AGO.
Neil: IT REALLY DROVE HOME
HOW LITTLE WE STILL KNOW,
IN MANY WAYS, ABOUT ANOLES.
BUT EVEN SOME
OF THE MOST COMMON SPECIES,
THE ONES THAT SCIENTISTS
HAVE STUDIED FOR DECADES,
THERE ARE STILL THINGS
ABOUT THEIR LIVES
THAT WE JUST DON'T KNOW.
Jonathan: WHEN I GRADUATED
FROM COLLEGE, I SAID TO MYSELF,
"I'M NEVER GOING TO STUDY ANOLES
AGAIN BECAUSE WE KNOW IT ALL."
OF COURSE, THAT WAS NAIVE.
FAR FROM KNOWING IT ALL, WE'VE
BARELY SCRATCHED THE SURFACE.
♪
Nate: NEIL AND I HAD FOLLOWED
THE ANOLE STORY
FOR MORE THAN A YEAR,
FROM CARIBBEAN RAINFORESTS
TO UNIVERSITY LABORATORIES,
FROM TINY BAHAMIAN ISLANDS
TO THE CITY OF MIAMI.
WE STARTED THIS QUEST
THINKING WE UNDERSTOOD
WHY ANOLES WERE SPECIAL,
BUT OUR JOURNEY LEFT US
WITH SOMETHING MORE PROFOUND.
Neil: GOING AND SEEING
THE DIVERSITY OF ANOLES
IN AN ISLAND
LIKE PUERTO RICO,
IT'S LIKE GOING
TO THE LOUVRE IN PARIS
AND APPRECIATING THE ART THERE.
IT'S SOMETHING THAT'S BEAUTIFUL
AND COMPLEX AND FASCINATING,
COMPLETELY OF ITS OWN ACCORD.
♪
Nate: WHEN I WAS A SCIENTIST
STUDYING LIZARDS,
PEOPLE WOULD ALWAYS ASK ME,
"WHY ARE YOU STUDYING LIZARDS?"
AND I THINK THAT IT'S,
IT'S NORMAL TO BE SKEPTICAL.
IT'S HARD TO UNDERSTAND WHY
IT COULD POSSIBLY BE IMPORTANT
TO DEDICATE ALL THIS EFFORT
INTO UNDERSTANDING HOW
THESE LIZARDS LIVE THEIR LIVES.
BUT LIFE ON EARTH
IS INCREDIBLY COMPLICATED,
AND UNDERSTANDING THE RULES
THAT GENERATED THAT DIVERSITY
IS FUNDAMENTAL TO UNDERSTANDING
WHERE WE FIT
INTO THE BIGGER PICTURE,
AND VERY FEW OTHER ORGANISMS
HAVE TAUGHT US AS MUCH
ABOUT THOSE RULES AS ANOLES.
♪
♪
THE CREATURES WE STUDY
TO REVEAL HOW LIFE WORKS.
[GROWLS]
WHAT DO YOU SEE?
FRUIT FLIES,
WHICH REVOLUTIONIZED GENETICS?
CHIMPANZEES, WHICH TEACH US
ABOUT THE ORIGINS
OF INTELLIGENCE?
WHAT ABOUT MICE, WHICH HELP US
UNDERSTAND HUMAN DISEASES?
WHATEVER YOU'RE IMAGINING,
IT PROBABLY ISN'T A LIZARD
IN A SUBURBAN BACKYARD.
BUT RESEARCHERS STUDYING
ONE SPECIAL GROUP OF LIZARDS
ARE DISCOVERING ANSWERS
TO BIG QUESTIONS
ABOUT LIFE ON EARTH.
♪
HOW DO ANIMALS ADAPT
TO DIFFERENT ENVIRONMENTS?
HOW CAN SO MANY SPECIES
COEXIST IN ONE PLACE?
AND HOW FAST
CAN EVOLUTION HAPPEN?
Man: WHEN SCIENTISTS
HAVE HAD BIG QUESTIONS
ABOUT THE WORLD AROUND US,
TIME AND TIME AGAIN
OVER THE LAST CENTURY,
THEY'VE TURNED TO ANOLES
TO ANSWER THOSE QUESTIONS.
Neil: MY NAME IS NEIL LOSIN.
Nate Dappen:
AND MY NAME IS NATE DAPPEN.
NEIL AND I ARE BIOLOGISTS
AND WILDLIFE FILMMAKERS.
WE'RE ON A YEAR-LONG JOURNEY,
TRAVELING FROM REMOTE FORESTS
AND TINY ISLANDS
TO HIGH-TECH LABS
AND BIG CITIES,
ALL IN PURSUIT OF THESE LIZARDS
THAT DEFY OUR EXPECTATIONS.
AS THEY BATTLE THEIR RIVALS,
EVADE PREDATORS,
AND SURVIVE
IN HOSTILE ENVIRONMENTS,
THESE LITTLE LIZARDS
SEEM TO MEET EVERY CHALLENGE
WITH AN INGENIOUS ADAPTATION.
IN THE PROCESS,
THEY REVEAL HOW SIMPLE RULES,
WHAT NEIL AND I
CALL THE LAWS OF THE LIZARD,
CAN EXPLAIN
THE COMPLEXITY OF NATURE.
YES, YES, YES, YES, YES!
OH!
YOU GOT HIM!
[LAUGHS]
Neil: ONE OF THE RAREST ANOLES
IN THE WORLD.
Nate: COME WITH US AND DISCOVER
HOW THESE UNASSUMING LIZARDS
ARE CHANGING THE WAY WE THINK
ABOUT LIFE ON EARTH.
♪
Neil: EVERY LIZARD BIOLOGIST
REMEMBERS THEIR FIRST,
THAT IS, THE FIRST LIZARD
THEY EVER STUDIED.
THE LIZARD
THAT TOOK NATE'S INNOCENCE
WAS A STRANGE COSTA RICAN
SPECIES CALLED THE RIVER ANOLE.
NATE AND I BOTH GOT OUR PhDs
STUDYING LIZARDS.
AND OVER THE LAST TEN YEARS,
WE'VE BECOME COLLABORATORS,
BUSINESS PARTNERS,
AND BEST FRIENDS.
THROUGH ALL OF THAT,
NATE HAS NOT SHUT UP
ABOUT THAT RIVER ANOLE,
SO WE'RE STARTING OUR JOURNEY
IN NATE'S OLD STOMPING GROUNDS
IN THE MOUNTAINS OF COSTA RICA
TO FIND THE LIZARD
THAT WAS SO INTERESTING,
IT CONVINCED NATE
TO BECOME A BIOLOGIST.
♪
Nate: IF YOU GET
A CHANCE TO SEE A RIVER ANOLE,
THE FIRST THING THAT IT'LL DO
IS SORT OF MOVE
TO THE OTHER SIDE OF THE ROCK
OR THE BRANCH THAT IT'S ON.
IF IT THINKS
THAT YOU'RE A REAL THREAT,
IT WILL DO SOMETHING AMAZING.
♪
SOMETIMES, RIVER ANOLES
REAPPEAR DOWNSTREAM
AFTER JUST A FEW SECONDS.
IT'S HARD TO PREDICT
EXACTLY WHERE THEY'LL POP UP.
OTHER TIMES,
THEY JUST SEEM TO VANISH.
WHAT ARE THEY DOING
WHEN THEY DISAPPEAR?
Neil: ALMOST AS SOON AS WE GOT
OUR CAMERA UNDER THE WATER,
WE WERE DOCUMENTING A BEHAVIOR
THAT'S ESSENTIALLY
UNKNOWN TO SCIENCE.
Nate: ONE FEMALE CLUNG
TO A ROCK UNDERWATER
FOR ALMOST TEN MINUTES.
WE FIGURED SHE MUST BE
HOLDING HER BREATH,
BUT WHEN WE WATCHED OUR FOOTAGE,
WE SAW SOMETHING
THAT BLEW US AWAY.
LOOK CAREFULLY, AND YOU CAN SEE
A LITTLE AIR BUBBLE
GROWING AND SHRINKING
ON HER HEAD.
IT LOOKS LIKE
SHE'S REBREATHING HER AIR,
LIKE A DEEP-SEA DIVER
RECYCLING HER OXYGEN SUPPLY.
RESEARCHERS
AT THE UNIVERSITY OF TORONTO
ARE NOW TRYING TO UNDERSTAND
THIS REBREATHING BEHAVIOR.
THE FIRST LAW OF THE LIZARD--
EXPECT SURPRISES.
♪
IT'S AN EXCITING START
TO A QUEST WE'VE BEEN THINKING
ABOUT EVER SINCE WE MET.
Neil: I MET NATE DAPPEN IN 2008
IN COSTA RICA
WHEN WE WERE BOTH STUDENTS
ON THE SAME
TROPICAL BIOLOGY COURSE.
Nate: WE WERE SO SIMILAR,
IT WAS KIND OF SPOOKY.
AND SO, WE'RE THE SAME HEIGHT,
SAME SIZE.
WE CAN FIT INTO EACH OTHER'S
CLOTHES IF WE NEED TO.
AND WE WERE BOTH
STUDYING EVOLUTION,
AND WE WERE BOTH
REALLY INTO PHOTOGRAPHY,
AND SO WE EITHER
HAD THE DECISION
TO DESTROY EACH OTHER
OR JOIN FORCES.
Neil: LUCKILY FOR NATE,
WE DECIDED
NOT TO DESTROY EACH OTHER.
INSTEAD, WE STARTED WORKING
TOGETHER ON EXPERIMENTS,
PHOTOGRAPHY PROJECTS,
AND EVENTUALLY ON FILMS.
Nate: AND WE SORT OF HAD
THIS DECISION TO MAKE--
DID WE WANT TO CONTINUE ON
AND BE RESEARCHERS,
OR DID WE WANT
TO GO INTO FILM FULL TIME?
AND WE SORT OF DECIDED TOGETHER
THAT WE WERE GONNA
TAKE THE PLUNGE
AND START MAKING SCIENCE FILMS
PROFESSIONALLY.
Neil: EVER SINCE, NATE AND I
HAVE TRAVELED AROUND THE WORLD
MAKING FILMS
ABOUT WILDLIFE AND SCIENCE.
ONE FILM
WE'VE ALWAYS WANTED TO MAKE
IS THE STORY
OF THESE LITTLE CREATURES
THAT HAVE HAD A HUGE IMPACT
ON OUR UNDERSTANDING OF LIFE.
WE WANTED TO TELL
THE STORY OF ANOLES.
Nate: WE'VE ALL SEEN
DOCUMENTARIES
WITH LIONS AND SHARKS
AND ELEPHANTS,
BUT NONE OF THOSE SPECIES
HAVE HAD REMOTELY
THE SAME KIND OF IMPACT
ON OUR UNDERSTANDING OF BIOLOGY
AS ANOLES HAVE.
Neil: FROM EVOLUTION
TO ECOLOGY, GENETICS,
PHYSIOLOGY,
EVEN CONSERVATION BIOLOGY.
♪
SO, WHAT ARE ANOLES?
THEY'RE A GROUP OF
CLOSELY RELATED LIZARD SPECIES
THAT LIVE
ALL OVER THE AMERICAN TROPICS.
THERE ARE MORE THAN 400 SPECIES
OF ANOLES
WITH A WIDE RANGE OF COLORS,
SIZES, AND BEHAVIORS.
BUT DESPITE ALL THIS VARIATION,
ANOLES SHARE TWO TRAITS THAT SET
THEM APART FROM OTHER LIZARDS,
AND THAT'S THE DEWLAP,
WHICH IS A COLORFUL FLAP OF SKIN
THAT EXTENDS FROM THE THROAT,
AND STICKY, ADHESIVE TOE PADS
ON THEIR FEET,
WHICH ALLOW THEM TO CLIMB
ON SMOOTH SURFACES LIKE LEAVES.
SOME OTHER LIZARDS
HAVE DEWLAPS OR TOE PADS,
BUT ONLY ANOLES HAVE BOTH.
Nate: THE DEWLAP
IS USED TO COMMUNICATE
WITH MEMBERS
OF THE SAME SPECIES.
MALES USE IT
TO TELL OTHER MALES,
"HEY, THIS IS MY TERRITORY.
DON'T MESS WITH ME,"
OR THEY USE IT TO SHOW FEMALES,
"HEY, COME OVER HERE,
I'VE GOT THIS GREAT TERRITORY,
AND I'M REALLY ATTRACTIVE."
Neil: TO WARD OFF
A POTENTIAL RIVAL,
A MALE ANOLE WILL PERFORM
A SORT OF RITUALIZED DISPLAY.
HE'LL DO PUSH-UPS,
AND HE'LL FLASH HIS DEWLAP.
IF THAT DOESN'T
INTIMIDATE HIS RIVAL,
THEIR ENCOUNTER CAN ESCALATE
INTO A VIOLENT BATTLE.
♪
IF THE MALE
CAN DEFEND HIS TERRITORY,
HE'LL HAVE OPPORTUNITIES
TO COURT FEMALES
AND, IF HE'S LUCKY,
A CHANCE TO MATE.
♪
Nate: ANOLES ARE FIERCE
HUNTERS THAT CHASE DOWN AND EAT
ALMOST ANYTHING
THAT FITS IN THEIR MOUTHS...
FROM INSECTS AND SPIDERS
TO OTHER LIZARDS,
EVEN MEMBERS
OF THEIR OWN SPECIES.
♪
ONE THE MOST SURPRISING THINGS
ABOUT ANOLES
IS THAT GENERATIONS
OF SCIENTISTS
HAVE DEDICATED THEIR LIVES
TO STUDYING THESE CRITTERS.
TO UNDERSTAND WHY,
WE NEED TO INTRODUCE YOU
TO THE MAN AT THE CENTER
OF THE ANOLE UNIVERSE.
Man: IF YOU MENTION
ANOLES TO ANYBODY,
THEY'RE GOING TO THINK
OF JONATHAN LOSOS.
Man: FIRST PERSON THAT
JUMPS TO MIND IS JONATHAN LOSOS.
Man: JONATHAN LOSOS.
Man: JONATHAN LOSOS.
Woman: JONATHAN LOSOS.
Man: YEAH, I WOULD SAY
JONATHAN LOSOS IS THE BOB DYLAN
OF ANOLE LIZARD BIOLOGY.
Woman: THE LEONARDO DA VINCI.
Man: THE GODFATHER.
Woman: THE JOHN LENNON.
Man: THE BARACK OBAMA.
Man: THE...
...ALBUS DUMBLEDORE
OF LIZARD BIOLOGY.
Man: AND JONATHAN
HAS LITERALLY WRITTEN THE BOOK
ON, ON ANOLE BIOLOGY.
Jonathan Losos: THE TWO MOST
COMMON WAYS OF PRONOUNCING IT
ARE "AN-OLE" AND "UH-NOLE."
AND THERE'S NO RIGHT OR WRONG.
AND I ACTUALLY GO
BACK AND FORTH, EITHER ONE,
FOR NO PARTICULAR REASON.
Man: I MEAN, HE JUST
REALLY LOVES ANOLIS LIZARDS.
HE JUST ALSO HAPPENS TO BE
A BRILLIANT SCIENTIST.
Nate: WE CAUGHT UP
WITH JONATHAN IN COSTA RICA
TO FIND OUT HOW HIS NAME
BECAME SYNONYMOUS WITH ANOLES.
Jonathan:
THERE'S A PICTURE OF ME
WHEN I WAS ABOUT EIGHT IN MIAMI,
AND I'D JUST CAUGHT
A, A LITTLE GREEN ANOLE.
IT'S A PICTURE OF ME LOOKING
VERY DOOFY WITH A GREEN ANOLE,
SO I GO WAY BACK WITH THEM.
Nate: IT SOUNDED LIKE DESTINY
THAT JONATHAN WOULD BECOME
AN ANOLE RESEARCHER.
Jonathan: AND SO I'VE BEEN
STUDYING ANOLES EVER SINCE.
Nate: AND DO YOU KNOW
ANY GOOD ANOLE PUNS?
Jonathan: WELL, ONLY ONE.
IT'S ANOLE-Y, BUT A GOODIE.
[IMITATES RIMSHOT]
Neil: OH!
Nate: I FIRST MET JONATHAN
WHEN I WAS A GRADUATE STUDENT,
AND HE TRIED TO CONVINCE ME
TO STUDY ANOLES.
Jonathan: I REMEMBER THAT.
I SAID,
THE GUY'S LIVING IN MIAMI,
AND HE WANTS TO GO TO SPAIN
TO DO HIS PhD
WHEN THERE ARE ANOLES
IN HIS BACKYARD.
CRAZY MAN!
Nate: I KNOW, BUT WHAT I DID
INSTEAD IS I CONVINCED THIS GUY.
Neil: HE PAID IT FORWARD.
Jonathan: WELL, ALL RIGHT.
EXCELLENT.
SO, FAILURE, SUCCESS.
THAT'S HOW I LOOK AT IT.
Neil: I SPENT THREE YEARS
STUDYING ANOLES IN MIAMI,
WHERE THEY'RE JUST PART OF LIFE.
YOU'D RUN INTO PEOPLE--
JOGGERS, DOG WALKERS-
AND MOST PEOPLE
HAVE SOME AWARENESS OF ANOLES.
BUT PEOPLE ARE USUALLY SURPRISED
TO LEARN THAT I'M NOT JUST
THIS ONE RANDOM WEIRDO
OUT THERE IN THE PARK,
BUT THERE ARE ACTUALLY
HUNDREDS OF BIOLOGISTS,
INCLUDING SOME OF
THE TOP SCIENTISTS IN THE WORLD,
WHO ARE STUDYING
THESE PARTICULAR LIZARDS.
Jonathan:
IT'S HARD TO KNOW FOR SURE
HOW MANY PAPERS ON ANOLES HAVE
BEEN PUBLISHED OVER THE YEARS.
I WOULD GUESS 5,000,
MAYBE 10,000.
Nate: SO, A LOT OF PEOPLE
STUDY ANOLES,
BUT WHERE DOES
THE ANOLE STORY BEGIN?
A GOOD PLACE TO START IS
THE WORLD'S LARGEST COLLECTION
OF REPTILES AND AMPHIBIANS
AT THE SMITHSONIAN NATIONAL
MUSEUM OF NATURAL HISTORY.
Kevin de Queiroz: WE HAVE
ALMOST 600,000 SPECIMENS
OF AMPHIBIANS AND REPTILES.
OF THOSE 600,000,
ABOUT 18,000 OF THEM
ARE ANOLIS LIZARDS.
Neil: THESE SCIENTIFIC
COLLECTIONS ARE LIKE
A COMBINATION DICTIONARY AND
ENCYCLOPEDIA OF LIFE ON EARTH.
THEY SHOW SCIENTISTS
WHAT SPECIES LOOK LIKE TODAY
AND HOW THEY'VE CHANGED
OVER TIME.
UNFORTUNATELY, ANOLE FOSSILS
ARE INCREDIBLY RARE,
SO, UNTIL RECENTLY, THE FOSSIL
RECORD DIDN'T SHED MUCH LIGHT
ON THE ANCIENT HISTORY
OF ANOLES.
BUT ALL THAT CHANGED
WITH RECENT DISCOVERIES
ON THE ISLAND OF HISPANIOLA.
Kevin: THERE'S A FAMOUS
AMBER INDUSTRY
THAT'S BEEN GOING ON THERE
FOR A LONG TIME.
THEY'RE USED FOR JEWELRY,
BUT OCCASIONALLY YOU FIND
BABY LIZARDS IN THERE, TOO.
Nate: ONE OF THE MOST
BEAUTIFUL THINGS I'VE EVER SEEN
WAS A 20-MILLION-YEAR-OLD ANOLE
TRAPPED IN AMBER.
THERE WERE BUBBLES IN THE STONE
THAT TRULY CONTAINED THE AIR
THAT THAT LIZARD BREATHED.
THESE LIZARDS TRAPPED IN AMBER
SHOW US THAT ANOLES
HAVE BEEN LIVING AND EVOLVING
ON THE ISLANDS OF THE CARIBBEAN
FOR TENS OF MILLIONS OF YEARS.
THAT HISTORY IS PRESERVED
IN THE JARS THAT LINE THE WALLS
OF THESE COLLECTIONS.
LOOK CLOSELY,
AND YOU'LL START TO APPRECIATE
THAT THESE LITTLE LIZARDS
ARE THE KEY TO A BIG STORY--
THE STORY OF LIFE
AND HOW IT EVOLVES.
TO DISCOVER THE SECRETS
THAT ONLY ANOLES CAN REVEAL,
WE NEED TO FOLLOW
IN THE FOOTSTEPS
OF GENERATIONS OF SCIENTISTS.
WE NEED TO GO TO THE CARIBBEAN.
HERE IN PUERTO RICO,
A WORLD OF SURPRISES IS WAITING.
Neil: IN THE CARIBBEAN, LAND
COMES IN ALL SHAPES AND SIZES.
IF YOU VISIT THE BIGGEST ISLANDS
IN THE CARIBBEAN,
THE FIRST THING YOU'LL NOTICE
IS THAT THEY'RE CRAWLING
WITH ANOLES.
LOOK CLOSELY,
AND YOU'LL SEE THAT THESE ANOLES
COME IN ALL SHAPES AND SIZES,
TOO.
AND JUST LIKE BODYBUILDERS
AND BALLERINAS,
AN ANOLE'S ANATOMY
CAN TELL US A LOT
ABOUT HOW IT MAKES A LIVING.
STEP INTO A PUERTO RICAN FOREST,
AND YOU CAN SEE WHAT I MEAN.
YOU WON'T HAVE TO WAIT LONG
TO SEE YOUR FIRST ANOLE.
MAYBE IT'LL BE A BROWN ANOLE
WITH LONG LEGS
ON THE TRUNK OF A TREE.
HIGHER IN THE TREE,
YOU MIGHT FIND A GREEN ANOLE
WITH SHORTER LEGS
CLIMBING IN THE LEAVES
AND BRANCHES.
AND DOWN BY YOUR FEET, AN ANOLE
WITH A LONG TAIL AND STRIPES
THAT DISAPPEARS INTO THE GRASS
IF YOU GET TOO CLOSE.
HIGH IN THE CANOPY,
IF YOU'RE LUCKY,
YOU MIGHT SEE
A MASSIVE GREEN ANOLE
WITH STRONG JAWS
AND HUGE TOE PADS.
AND IF YOU SIT REALLY STILL,
YOU COULD SPOT A TINY ANOLE
WITH A SHORT TAIL
AND STUBBY LEGS
CLINGING TO THE SMALLEST TWIGS
IN THE FOREST.
ALL OF THESE ANOLES
LIVE SIDE BY SIDE
HERE IN PUERTO RICO,
BUT THEY AREN'T JUST
RANDOMLY SCATTERED ALL OVER.
THEY SPECIALIZE,
SO YOU TEND TO FIND EACH TYPE
IN A DIFFERENT PART
OF THE FOREST.
SOME LOW, SOME HIGH.
SOME ON THE TREE TRUNKS
AND OTHERS
OUT ON THE SMALLEST TWIGS.
HOP OVER TO A SECOND ISLAND,
AND THE PATTERN BECOMES CLEARER.
HERE IN THE DOMINICAN REPUBLIC,
THE ANOLE SPECIES ARE DIFFERENT
THAN THE ONES IN PUERTO RICO,
BUT LOOK AROUND,
AND IT'LL FEEL LIKE DEJA VU.
YOU'LL FIND ANOLES
IN ALL THE SAME PLACES
YOU SAW THEM IN PUERTO RICO--
LONG-LEGGED BROWN ANOLES
ON THE TREE TRUNKS,
ANOLES WITH LONG TAILS
AND STRIPES IN THE GRASSES,
GIANT GREEN ANOLES
IN THE CANOPY, AND SO ON.
THE SPECIES PLAYING THESE ROLES
ARE DIFFERENT,
BUT THEY LOOK STRIKINGLY SIMILAR
BETWEEN ISLANDS.
IT'S ALMOST AS IF DIFFERENT
LOOK-ALIKE ACTORS
WERE PERFORMING THE SAME SHOW.
ACROSS THE CARIBBEAN,
ANOLES THAT LIVE
IN THE SAME PART OF THE FOREST
SHARE SIMILAR
ANATOMICAL FEATURES,
NO MATTER WHICH ISLAND
THEY INHABIT.
IT'S SUCH AN UNUSUAL PATTERN
THAT ANOLE RESEARCHERS
INVENTED A WORD TO DESCRIBE IT.
THEY CALLED THESE ANOLE TYPES
THAT REPEAT FROM ISLAND
TO ISLAND "ECOMORPHS."
Jonathan:
THE ECOMORPHS ARE NAMED
FOR WHERE IN THE ENVIRONMENT
YOU USUALLY FIND THEM--
TRUNK GROUND,
TRUNK,
TRUNK CROWN,
THE CROWN GIANT,
TWIG,
AND GRASS BUSH.
Neil: CUBA, HISPANIOLA,
JAMAICA, AND PUERTO RICO
EACH HAVE DIFFERENT SPECIES,
BUT THEY ALL HAVE
THE SAME ECOMORPHS.
THE QUESTION IS, WHY DO LIZARDS
LIVING IN THE SAME HABITAT
BUT ON DIFFERENT ISLANDS
LOOK SO SIMILAR?
Jonathan: WHY DO THE ONES
NEAR THE GROUND HAVE LONG LEGS
AND THE ONES UP IN THE TREES
HAVE SHORT LEGS?
WHY UP IN THE TREE
DO THEY HAVE BIG TOE PADS
AND THEY'RE OFTEN GREEN
AND THE ONES DOWN ON THE GROUND
HAVE SMALLER TOES PADS
AND ARE BROWN IN COLOR?
Nate: JONATHAN SUSPECTED
THAT EACH ECOMORPH'S
ANATOMICAL FEATURES
HELPED IT SURVIVE
IN A PARTICULAR PART
OF THE FOREST.
HE HATCHED AN INGENIOUS PLAN
TO PUT THIS IDEA TO THE TEST.
Jonathan: THE WAY WE TEST THAT
IS BASICALLY BY HAVING
THE LIZARD OLYMPICS.
Nate: JONATHAN CAPTURED
15 DIFFERENT ANOLE SPECIES
IN PUERTO RICO AND JAMAICA,
AND HE BROUGHT THEM INTO THE LAB
TO MEASURE
THEIR SPRINTING SPEED,
JUMPING ABILITY,
AND TOE PAD CLINGING POWER.
THE SPECIES THAT LIVE
HIGH IN THE TREES,
THE TRUNK CROWNS
AND CROWN GIANTS,
HAVE THE BIGGEST TOE PADS.
THESE TOE PADS HELP THEM STICK
TO SMOOTH SURFACES LIKE LEAVES
SO THEY DON'T
FALL OUT OF THE TREES.
TRUNK GROUND ANOLES
HAVE LONG LEGS,
WHICH HELP THEM JUMP FAR
AND RUN FAST ON FLAT SURFACES.
THESE ARE CRITICAL SKILLS
FOR A LIZARD
THAT HAS TO CAPTURE PREY AND
ESCAPE PREDATORS ON THE GROUND.
JONATHAN'S LIZARD OLYMPICS
CONFIRMED WHAT HE SUSPECTED,
THAT EACH ECOMORPH
HAS ADAPTATIONS
THAT HELP IT MOVE THROUGH
A DIFFERENT PART OF THE FOREST.
Jonathan: WE DID FIND
ONE INTERESTING TWIST
WE DIDN'T EXPECT.
WE THOUGHT THAT LIZARDS
WITH SHORT LEGS
WOULD BE FASTER
ON NARROW SURFACES.
TURNS OUT
THEY'RE NOT FASTER AT ALL.
Nate: THEY MAY NOT BE FAST,
BUT THE SHORT-LEGGED ANOLES
OF THE TWIG ECOMORPH
DO HAVE AN ADVANTAGE
ON THIN BRANCHES.
THEY HARDLY EVER FALL.
IN CONTRAST, LONG-LEGGED ANOLES
HAVE REAL TROUBLE
MANEUVERING ON TWIGS.
Jonathan: THEY REACH AROUND
TO GET THE TWIG,
AND SOMETIMES THEY JUST MISS,
AND THEY JUST FALL OFF THE TWIG.
Nate: FOR AN ANOLE,
BEING ABLE TO MOVE QUICKLY AND
CONFIDENTLY THROUGH THE FOREST
MIGHT MEAN THE DIFFERENCE
BETWEEN A FULL BELLY
AND AN EMPTY ONE,
OR EVEN BETWEEN LIFE AND DEATH.
Neil: IMAGINE AN ANOLE SPECIES
LIVING DOWN NEAR THE GROUND.
JUST BY CHANCE, SOME HAVE GENES
THAT GIVE THEM LONGER LEGS
THAN OTHERS.
THESE LONG-LEGGED LIZARDS
CAN RUN FAST,
SO THEY'RE GREAT
AT CATCHING PREY
AND ESCAPING PREDATORS
ON THE GROUND.
ON AVERAGE,
THESE LONG-LEGGED ANOLES
WILL PRODUCE MORE OFFSPRING
THAN SHORT-LEGGED ANOLES,
PASSING MORE OF THEIR GENES
ON TO THE NEXT GENERATION,
SO OVER MANY GENERATIONS,
THE WHOLE SPECIES
WILL EVOLVE LONGER LEGS.
THAT'S EXACTLY
HOW CHARLES DARWIN ENVISIONED
THE PROCESS
OF NATURAL SELECTION,
SO TO JONATHAN,
NATURAL SELECTION
IN DIFFERENT PARTS OF THE FOREST
COULD EXPLAIN WHY EACH ECOMORPH
EVOLVED ITS DISTINCTIVE TRAITS.
THE PROBLEM WAS, NO ONE WAS
THERE TO SEE EVOLUTION HAPPEN.
Jonathan: I ALWAYS COMPARE
STUDYING EVOLUTION
TO BEING LIKE A DETECTIVE STORY.
WE'VE GOT A WHODUNIT.
WHAT HAPPENED IN THE PAST?
WHY DID IT HAPPEN?
WE CAN'T GO BACK IN TIME,
SO WE HAVE TO USE
WHATEVER CLUES WE HAVE
TO PIECE IT ALL TOGETHER
TO FIGURE OUT
WHAT HAPPENED IN THE PAST.
Neil: SINCE EACH ISLAND
HAS DIFFERENT SPECIES
BUT THE SAME ECOMORPHS,
THE BIG QUESTION IS WHETHER
THESE ECOMORPHS EVOLVED ONCE
AND THEN SPREAD
TO THE DIFFERENT ISLANDS
OR EVOLVED SEPARATELY
ON EACH ISLAND.
Jonathan: TO DISTINGUISH
BETWEEN THESE POSSIBILITIES,
WE NEED TO RECONSTRUCT
THE EVOLUTIONARY HISTORY
OF ANOLES IN THE CARIBBEAN.
AN EVOLUTIONARY TREE
IS A DIAGRAM THAT ILLUSTRATES
THE EVOLUTIONARY RELATIONSHIPS
OF A SPECIES.
Neil: LIKE A REAL TREE,
AN EVOLUTIONARY TREE BEGINS
AS A SINGLE STEM,
A SINGLE ANCESTOR SPECIES.
WHEN THAT ONE SPECIES SPLITS
INTO TWO, THE STEM BRANCHES.
AS THE TREE GROWS, SOME BRANCHES
DIE BACK AS SPECIES GO EXTINCT,
BUT OTHERS KEEP GROWING
AND BRANCHING.
FOR A GROUP LIKE ANOLES,
WITH HUNDREDS OF LIVING SPECIES,
FIGURING OUT THE EVOLUTIONARY
TREE IS A DAUNTING TASK.
ONE TYPE OF EVIDENCE
THAT HELPS SCIENTISTS
BUILD EVOLUTIONARY TREES
IS SOMETHING YOU CAN FIND
INSIDE EVERY PLANT AND ANIMAL
ON EARTH--DNA.
Jonathan: DNA CHANGES OVER TIME.
IT EVOLVES.
THE LONGER TWO SPECIES
HAVE BEEN DIVERGING SEPARATELY,
THE GREATER THE DIFFERENCE
WILL BE IN THEIR DNA,
AND SO BY SEQUENCING THE DNA
OF MANY SPECIES,
YOU CAN BUILD
AN EVOLUTIONARY TREE.
Neil: THE SHAPE OF THAT TREE,
ITS PATTERN OF BRANCHING,
CAN HELP US UNDERSTAND
HOW ANOLES EVOLVED
AND SPREAD ACROSS ISLANDS.
AT ONE EXTREME,
ALL THE ECOMORPHS
COULD HAVE EVOLVED JUST ONCE,
THEN SPREAD
FROM ISLAND TO ISLAND.
AT THE OTHER EXTREME,
ANOLES COULD HAVE SPREAD
TO DIFFERENT ISLANDS FIRST,
AND THEN EVOLVED
INTO THE ECOMORPHS SEPARATELY
ON EACH OF THE FOUR ISLANDS.
Nate: JONATHAN AND HIS
COLLEAGUES COLLECTED DNA SAMPLES
FROM 55 SPECIES OF ANOLES
TO BUILD AN EVOLUTIONARY TREE
THAT ENCOMPASSED EVERY ECOMORPH
ON ALL FOUR ISLANDS.
Jonathan: HAD THE ECOMORPHS
TRULY EVOLVED INDEPENDENTLY
ON DIFFERENT ISLANDS?
WELL, THE DNA SHOULD TELL US.
Nate: THE TREE GAVE THEM
AN ASTONISHING ANSWER.
DESPITE ALL THE VARIATION
AMONG THEM,
ANOLES LIVING ON THE SAME ISLAND
WERE MORE CLOSELY RELATED
TO EACH OTHER
THAN TO SPECIES
ON OTHER ISLANDS,
EVEN THE ONES
THAT LOOKED STRIKINGLY SIMILAR.
THIS MEANT THAT ANOLES
HAD COLONIZED
THE DIFFERENT ISLANDS FIRST
AND THEN EVOLVED ON EACH ISLAND
INTO A VIRTUALLY IDENTICAL
COMMUNITY OF ECOMORPHS.
Jonathan: NO ONE COULD EVER
ARGUE ABOUT THAT AGAIN.
THEY EVOLVED INDEPENDENTLY
ON EACH ISLAND.
Nate: THESE SCIENTISTS
HAD REVEALED
ANOTHER LAW OF THE LIZARD--
WHEN THEY LIVE
IN THE SAME TYPE OF ENVIRONMENT,
DIFFERENT SPECIES EVOLVE
SIMILAR TRAITS TO SURVIVE
AGAIN AND AGAIN AND AGAIN.
Jonathan: WELL,
PEOPLE WERE VERY EXCITED
WHEN THIS RESULT CAME OUT
BECAUSE IT SHOWED THAT
EVOLUTION DOES REPEAT ITSELF,
THAT THERE ARE RULES
TO EVOLUTION.
Nate: MANY SCIENTISTS THOUGHT
THAT NATURE WAS SO COMPLEX
AND EVOLUTION UNFOLDED
OVER SUCH LONG TIMESCALES
THAT YOU'D RARELY SEE
THE SAME OUTCOME TWICE.
Jonathan: THEY SUGGESTED
THAT IF YOU COULD SOMEHOW
REPLAY THE TAPE OF LIFE,
YOU WOULD GET
A DIFFERENT OUTCOME EVERY TIME.
BUT HERE YOU GOT THE SAME
OUTCOME FOUR TIMES IN A ROW
ON DIFFERENT ISLANDS.
Nate: JONATHAN DECIDED TO DIG
DEEPER INTO THIS INTRIGUING IDEA
THAT EVOLUTION WAS PREDICTABLE.
Jonathan: IT WOULD BE GREAT
TO ACTUALLY DO AN EXPERIMENT
TO TEST THE HYPOTHESIS
THAT NATURAL SELECTION DRIVES
THE EVOLUTION OF THESE FEATURES.
Nate: JONATHAN WAS
ABOUT TO VENTURE
INTO NEW SCIENTIFIC TERRITORY
AND DISCOVER SOMETHING
THAT DARWIN
NEVER WOULD HAVE IMAGINED.
Jonathan:
IT'S A LITTLE-KNOWN FACT
THAT CHARLES DARWIN
WAS A GREAT EXPERIMENTER,
BUT HE NEVER DID AN EXPERIMENT
ABOUT HIS MOST IMPORTANT IDEA--
THE THEORY OF EVOLUTION
BY NATURAL SELECTION.
AND THE REASON HE DIDN'T DO
AN EXPERIMENT IS OBVIOUS.
HE THOUGHT THAT EVOLUTION
MOVED INCREDIBLY SLOWLY,
GLACIALLY SLOWLY.
HE THOUGHT IT WOULD TAKE
THOUSANDS OF YEARS
TO LEAD TO CHANGES
THAT WE COULD DETECT.
WELL, DARWIN WAS RIGHT ABOUT
AN AMAZING NUMBER OF HIS IDEAS,
BUT THIS IS ONE IDEA
ABOUT WHICH HE WAS WRONG.
Neil: IT TURNS OUT THAT ANOLES
CAN SHOW US SOMETHING
THAT DARWIN
NEVER COULD HAVE IMAGINED--
WHAT EVOLUTION LOOKS LIKE
AS IT'S HAPPENING.
TO SEE IT FOR OURSELVES,
WE'RE HEADING TO THE BAHAMAS.
ON THE FOUR BIGGEST ISLANDS
OF THE CARIBBEAN,
ANOLES HAVE EVOLVED TO THRIVE IN
DIFFERENT PARTS OF THE FOREST,
AND THEIR DNA REVEALS
THAT THEY DID SO INDEPENDENTLY
ON EACH ISLAND.
THESE EVENTS
TOOK MILLIONS OF YEARS,
BUT WHAT IF YOU COULD WATCH
EVOLUTION HAPPEN?
CHARLES DARWIN
THOUGHT THAT THE EARTH
CHANGED GRADUALLY OVER EONS,
AND SINCE PLANTS AND ANIMALS
ADAPT TO THEIR ENVIRONMENTS,
HE THOUGHT
THE PROCESS OF EVOLUTION
HAD TO BE SLOW AS WELL.
BUT SOME ENVIRONMENTS
ARE MUCH MORE DYNAMIC
THAN DARWIN IMAGINED.
THE BAHAMAS
HAVE HUNDREDS OF TINY ISLANDS
THAT OFTEN GET HIT
BY HURRICANES.
HERE, SPECIES COLONIZE AND
GO EXTINCT FROM YEAR TO YEAR.
THAT MAKES THEM
THE PERFECT LABORATORY
TO STUDY
SURVIVAL AND ADAPTATION,
AND THAT'S WHAT BROUGHT
ECOLOGIST ROB PRINGLE HERE.
Rob Pringle: YOU KNOW, IF YOU DO
YOUR BEST MALE LIZARD
IMPERSONATION,
YOU MIGHT GET THE FEMALES
TO COME CHECK YOU OUT.
Neil: OH, YEAH, SHOULD I GET
DOWN AND DO SOME PUSH-UPS?
I WAS HELPING ROB CATCH ANOLES
FOR A MASSIVE EXPERIMENT
ON ANOLE EVOLUTION.
Rob: EASIEST AND BEST WAY TO
CATCH AN ANOLE IS TO NOOSE IT,
WHICH IS BASICALLY, IT'S LAND
FISHING FOR LIZARDS, YOU KNOW?
SO, YOU TAKE A FISHING POLE,
AND YOU TIE A LITTLE SLIPKNOT
AT THE END OF IT,
AND YOU TRY TO LOOP THAT
AROUND THE HEAD OF A LIZARD,
AND THEN YOU PULL,
AND HOPEFULLY YOU HAVE A LIZARD
ON THE END OF YOUR STICK.
♪
Neil: OH, LOOK AT THIS GUY!
Nate: YOU HAVE TO BRING IT UP
TO YOUR FACE.
Neil: OH!
Nate: OH [BLEEP]
YOU ALL RIGHT?
WELL, I GOTTA SAY THAT WAS THE
WORST LIZARD CATCH IN HISTORY!
Neil: SO, I GOT THE LIZARD.
AND I ALSO FELL THIGH-DEEP
INTO A HOLE IN THE LIMESTONE.
BUT ME AND THE LIZARD ARE OKAY.
Rob: OH, THERE WE GO.
Neil: I'LL LEAVE IT TO
THE PROFESSIONALS FROM NOW ON.
Rob: WELL, YOU KNOW.
Neil: ROB AND HIS COLLEAGUES
BRING THE ANOLES
BACK TO THEIR PORTABLE LAB
TO SAMPLE THEIR DNA
AND TAKE X-RAYS
TO MEASURE THE LIZARDS' BONES
WITH PRECISION.
THEY'RE LOOKING FOR SIGNS
OF EVOLUTION
TAKING PLACE NOT OVER MILLENNIA,
BUT DURING AN EXPERIMENT
LASTING JUST A FEW YEARS.
AFTER YOU X-RAY HER
AND TAKE HER MEASUREMENTS,
THEN SHE'S GOING TO COME
RIGHT BACK TO THIS SAME PERCH?
Rob: THAT'S EXACTLY RIGHT.
Neil:
SHE'LL PROBABLY JUST THINK
IT WAS A REALLY WEIRD DREAM.
Rob: IT'LL JUST BE
A WEIRD DREAM,
SOMETHING SHE'LL TELL
HER FRIENDS ABOUT.
LIKE, "YOU GUYS WOULDN'T BELIEVE
WHAT HAPPENED TO ME,"
AND THEN NONE OF THEM
WILL BELIEVE HER.
Nate: ANOLE RESEARCHERS
HAVE BEEN COMING
TO THE BAHAMAS FOR DECADES
BECAUSE IT'S A PERFECT PLACE
TO STUDY LIZARD EVOLUTION.
Jonathan:
IF YOU GET A SMALL ENOUGH ISLAND
THAT YOU CAN STUDY
THE WHOLE POPULATION
AND YET BIG ENOUGH
THAT THEY CAN SURVIVE AND ADAPT,
IT'S ALMOST THE EQUIVALENT
OF A LABORATORY TEST TUBE.
Nate: IN THE 1970s,
ECOLOGIST TOM SCHOENER FOUND
SMALL ISLANDS WITHOUT ANOLES,
AND HE ADDED ANOLES TO STUDY
HOW POPULATIONS GROW, SHRINK,
AND EVENTUALLY GO EXTINCT.
SOME POPULATIONS DEFIED THE ODDS
AND CONTINUED TO THRIVE
YEAR AFTER YEAR.
THESE SURVIVORS GAVE JONATHAN
AN INTRIGUING IDEA.
WOULD THE LIZARDS ADAPT
TO THEIR NEW ISLAND HOMES?
Jonathan: THEY HAD INADVERTENTLY
SET UP AN EVOLUTION EXPERIMENT
BECAUSE THESE ISLANDS DIFFERED
IN THEIR CHARACTERISTICS.
TOM SCHOENER
HAD MOVED BROWN ANOLES
FROM A LARGER ISLAND,
STANIEL CAY,
WHERE THE LIZARDS LIVED
ON LARGE TREES,
TO THESE TINY LITTLE ISLANDS
THAT DIDN'T HAVE TREES.
THEY HAD NARROW BUSHES AND,
AND NARROW-STEMMED VEGETATION.
JUST LIKE TWIG ANOLES HAVING
SHORT LEGS ON NARROW VEGETATION,
WE PREDICTED
THAT THE BROWN ANOLES,
WHEN MOVED FROM A BROAD SURFACE
TO A NARROW SURFACE,
WOULD EVOLVE SHORTER LEGS.
Nate: DID THE SAME RULES
THAT MADE EVOLUTION PREDICTABLE
ON THE LARGE ISLANDS
OPERATE IN THE BAHAMAS, TOO?
AND IF SO, COULD WE WITNESS
EVOLUTION HAPPEN
IN JUST 14 YEARS?
FEW BIOLOGISTS
WOULD HAVE ASKED THIS QUESTION
BECAUSE MOST OF THEM
STILL THOUGHT
THAT ANIMALS EVOLVED TOO SLOWLY
TO OBSERVE IN A HUMAN LIFETIME,
BUT JONATHAN SAW AN OPPORTUNITY
TO PUT THIS CONVENTIONAL WISDOM
TO THE TEST.
Shane Campbell-Staton:
A BIG PART OF BIOLOGY
IS ABOUT CREATIVITY, RIGHT?
AND ABOUT UNDERSTANDING, LIKE,
WHAT IS THE RIGHT QUESTION?
THERE'S AN ARTISTRY THERE.
AND IF THAT'S AN ART,
THEN JONATHAN IS A PICASSO.
Nate: JONATHAN RETURNED
TO TOM SCHOENER'S ISLANDS
IN THE 1990s WITH A NEW PLAN--
TO COMPARE THE ANATOMY
OF THE NEW ISLAND POPULATIONS
AND THE ORIGINAL
SOURCE POPULATION.
IF THE ANOLES WERE DIFFERENT,
THAT WOULD SHOW
THAT THESE POPULATIONS
HAD EVOLVED IN JUST 14 YEARS.
Jonathan: AND THE RESULTS
FLASHED ON THE SCREEN.
THE POPULATIONS WERE DIFFERENT.
THEY HAD EVOLVED!
WELL, NEEDLESS TO SAY,
THIS WAS INCREDIBLY EXCITING.
Nate: THE ANOLES DIFFERED IN
JUST THE WAY JONATHAN EXPECTED.
ON THE ISLANDS
WITH SLENDER BRANCHES,
THE ANOLES
HAD EVOLVED SHORTER LEGS,
AND THEY DID SO
IN JUST 14 YEARS.
EVEN FOR ANOLES, WHICH CAN
REPRODUCE AT ONE YEAR OLD,
14 YEARS IS INCREDIBLY FAST.
Jonathan: OF COURSE, DARWIN
WOULD HAVE BEEN VERY SURPRISED.
HE THOUGHT THAT EVOLUTION
OCCURRED SO SLOWLY
THAT YOU COULDN'T
POSSIBLY SEE IT
UNTIL A THOUSAND YEARS
HAD ELAPSED.
ONCE WE REALIZED THAT ANOLES
WOULD ADAPT RAPIDLY
TO NEW CONDITIONS,
THAT OPENED OUR EYES TO OTHER
EXPERIMENTS WE COULD DO.
Nate: ANOLE RESEARCHERS
COULD NOW ASK NEW QUESTIONS,
LIKE HOW DO PREDATORS
AFFECT EVOLUTION?
AND THEY COULD ANSWER
THOSE QUESTIONS
NOT JUST BY DOING DETECTIVE WORK
ABOUT THE ANCIENT PAST,
BUT BY DOING EXPERIMENTS
AND WATCHING EVOLUTION UNFOLD
IN THE PRESENT.
THAT'S WHAT ROB PRINGLE
AND JASON KOLBE
ARE DOING IN THE BAHAMAS
RIGHT NOW.
Rob: SO, IT'S A,
IT'S A GOOD PLACE TO BE
IF YOU'RE A, A BROWN ANOLE.
Nate: LET'S GO PAINT
SOME LIZARDS!
Rob: LET'S GO
PAINT SOME LIZARDS!
Nate: ALL RIGHT!
ROB SHOWED ME HOW TO MARK ANOLES
WITH NON-TOXIC, WATER-SOLUBLE
PAINT FOR HIS EXPERIMENT.
Rob: YEAH, THERE'S A TON
OF LIZARDS ON THIS ISLAND.
Nate: THIS IS ALSO FUN.
Rob: YEAH, IT'S A LOT OF FUN!
Nate: IT'S LIKE SHOOTIN'
LIZARDS IN A BARREL.
Rob: SHOOTIN' LIZARDS
IN A TREE.
Nate: YES, IT'S KIND OF
EXACTLY LIKE THAT.
[LAUGHTER]
THE LIZARDS
WILL LOSE THESE PAINT MARKS
THE NEXT TIME
THEY SHED THEIR SKINS,
BUT THE PAINT DOESN'T NEED
TO LAST LONG.
BY MARKING ALL THE ANOLES
WE CAN FIND ONE DAY
AND RETURNING TO COUNT
THE MARKED AND UNMARKED ANOLES
THE NEXT DAY,
WE CAN ESTIMATE THE TOTAL NUMBER
OF ANOLES ON AN ISLAND.
Rob: LAST YEAR
WE HAD UPWARDS OF 400 LIZARDS
ON THIS ISLAND.
Nate: THIS POPULATION CENSUS
HELPS THE RESEARCHERS MONITOR
HOW THE ANOLES ARE DOING
ON DIFFERENT ISLANDS.
AND ON SOME ISLANDS,
THE ANOLES ARE IN REAL DANGER
BECAUSE ROB AND JASON HAVE ADDED
ANOTHER LIZARD INTO THE MIX,
ONE OF THE BROWN ANOLE'S
ENEMIES--
THE CURLY-TAILED LIZARD.
♪
♪
Neil: IT TURNS OUT
THAT CURLY-TAILED LIZARDS
DON'T JUST IMPACT THE NUMBERS
OF ANOLES ON ISLANDS.
THEY ACTUALLY CAUSE
NATURAL SELECTION.
Jason Kolbe:
WITHIN THE FIRST SIX MONTHS
OF THE CURLY TAILS BEING THERE,
ANOLES WITH LONGER HIND LIMBS
HAVE BETTER SURVIVAL,
AND PRESUMABLY
THAT'S BECAUSE THEY'RE FASTER
AT RUNNING ON THE GROUND
TO ESCAPE PREDATION
FROM THE CURLY-TAILED LIZARD.
Neil: GRADUALLY,
THE ANOLES BEGIN TO MOVE UP.
THEY SPEND LESS TIME
ON THE GROUND
AND MORE TIME
IN THE SLENDER BRANCHES.
ONCE THEY'RE OUT OF DANGER
FROM THE PREDATOR,
NATURAL SELECTION
HAS A DIFFERENT EFFECT.
Jason: DURING THAT PERIOD,
SELECTION REVERSES
AND FAVORS BROWN ANOLES
WITH SHORTER HIND LIMBS
BECAUSE THEY'RE OCCUPYING
THESE NARROWER BRANCHES,
AND ANOLES WITH SHORTER LIMBS
CAN MOVE BETTER
IN THAT ENVIRONMENT.
Neil: THESE EXPERIMENTS REVEAL
ANOTHER LAW OF THE LIZARD--
NATURAL SELECTION
IS HAPPENING ALL THE TIME,
AND IT'S DRIVEN
NOT ONLY BY THE ENVIRONMENT,
BUT ALSO BY OTHER SPECIES.
ONE SPECIES MORE THAN ANY OTHER
IS SHAPING THE NEXT ERA
OF LIZARD EVOLUTION.
HOW ARE ANOLES ADAPTING
TO THE AGE OF HUMANS?
TO FIND OUT, NATE AND I ARE
HEADING TO MY BACKYARD, MIAMI,
TO DISCOVER
THE ASTONISHING ADAPTATIONS
OF THESE LITTLE LIZARDS
IN THE BIG CITY.
Nate: OUR JOURNEY
HAS ALREADY SHOWN US
THAT ANOLES ARE EVOLVING
TO SURVIVE IN A CHANGING WORLD,
BUT NEVER IN THEIR HISTORY
HAVE ANOLES FACED
A MORE PERILOUS
OR UNCERTAIN ENVIRONMENT
THAN THE WORLD OF HUMANS.
Neil: LIVING IN MIAMI, I SEE
ANOLES AROUND ME EVERY DAY,
BUT A LOT OF THE ANOLES
I SEE IN MIAMI
DIDN'T ACTUALLY ORIGINATE THERE.
THEY COME FROM ISLANDS
ALL OVER THE CARIBBEAN.
Nate: SOUTHERN FLORIDA IS A
MELTING POT OF ANOLE IMMIGRANTS.
FLORIDA HAS ONLY ONE
NATIVE SPECIES OF ANOLE,
BUT EIGHT OTHER SPECIES HAVE
ESTABLISHED POPULATIONS HERE.
Neil: THEY GOT TO MIAMI EITHER
THROUGH THE PET TRADE
OR ACCIDENTALLY IN SHIPMENTS
OF PRODUCE AND OTHER GOODS
COMING FROM THE CARIBBEAN.
Nate: HUMANS DON'T JUST BRING
ANOLES INTO THE CITY.
AS WE CONVERT WILD FORESTS
INTO CONCRETE JUNGLES,
WE ALSO BRING THE CITY
TO ANOLES.
Jason: WHEN ANOLES ARRIVE
IN A NEW AREA,
THEY ENCOUNTER
NOVEL TYPES OF ENVIRONMENTS,
AND SO THERE ARE NEW PREDATORS,
THERE ARE NEW COMPETITORS.
MOST ANOLES LIVE
ON THE TRUNKS OF TREES,
BRANCHES OF TREES,
HIGHER UP IN THE CANOPY.
BUT IN THE URBAN ENVIRONMENT,
MUCH OF THIS VEGETATION
HAS BEEN REPLACED BY BUILDINGS
AND WALLS, LAMPPOSTS.
Nate: THOSE SURFACES CAN BE
SMOOTHER AND HARDER TO CLIMB
THAN TREES AND ROCKS,
AND THAT'S NOT
THE ONLY CHALLENGE OF CITY LIFE.
Jason: BY REPLACING
NATURAL VEGETATION
WITH CONCRETE, ASPHALT, THEY
CHANGE THE THERMAL ENVIRONMENT.
THEY'RE MUCH HOTTER
THAN A COMPARABLE NATURAL AREA.
Nate: SINCE LIZARDS
CAN'T REGULATE
THEIR BODY TEMPERATURES
INTERNALLY,
THE HEAT OF THE CITY COULD ALSO
THREATEN THEIR SURVIVAL.
Jonathan: IN SOME CASES, THE
CHALLENGES ARE TOO OVERWHELMING.
THEY JUST CAN'T DO IT,
BUT SOMETIMES
THEY'RE ABLE TO SURVIVE
AND PERHAPS EVEN ADAPT
TO THESE NEW CONDITIONS.
Neil: ONE OF THESE SURVIVORS IS
THE PUERTO RICAN CRESTED ANOLE,
WHICH THRIVES IN CITIES
THROUGHOUT PUERTO RICO.
RESEARCHERS KRISTIN WINCHELL
AND SHANE CAMPBELL-STATON
WANT TO UNDERSTAND
HOW THIS SPECIES
IS COPING WITH LIFE IN THE CITY.
Kristin Winchell:
THE OVERARCHING QUESTION
MY RESEARCH
IS TRYING TO TACKLE IS
CAN HUMANS INFLUENCE
THE COURSE OF EVOLUTION?
Shane: HOW FAST
CAN THESE ANIMALS CHANGE?
AND CAN THEY KEEP PACE
WITH HUMAN-MEDIATED CHANGES
IN THE ENVIRONMENT?
Kristin: I THINK
A LOT OF PEOPLE DO GET CONFUSED
WHEN I'M WALKING AROUND
IN URBAN AREAS.
I AM WALKING AROUND
WITH A FISHING POLE,
WHICH IS VERY STRANGE.
I'M STICKING MY FISHING POLE
UP TREES AND ON THEIR WALLS,
WHICH IS EVEN STRANGER,
AND SO WE,
WE GET A LOT OF QUESTIONS.
Neil: TO UNDERSTAND
WHETHER LIZARDS
ARE ADAPTING TO CITY LIFE,
KRISTIN AND SHANE COLLECT ANOLES
FROM URBAN AND NATURAL SITES
AND TAKE THEM
BACK TO THEIR FIELD LAB
TO COMPARE THEIR ANATOMY
AND PHYSICAL PERFORMANCE.
KRISTIN FOUND THAT,
COMPARED TO FOREST LIZARDS,
URBAN LIZARDS HAD LONGER LEGS
AND LARGER TOE PADS.
THE QUESTION IS, DO THESE TRAITS
MAKE A DIFFERENCE?
TO FIND OUT, KRISTIN PLANNED
A NEW LIZARD OLYMPICS
TO TEST THE ANOLES' PERFORMANCE
IN THE URBAN ENVIRONMENT.
THE FIRST EVENT
IN THIS COMPETITION?
URBAN AND FOREST LIZARDS
SPRINTED ON RACETRACKS
WITH THREE DIFFERENT SURFACES.
Kristin: WE'RE RUNNING THEM
ON PAINTED CONCRETE,
ON BARK, AND ON UNPAINTED METAL,
AND SO WE'RE
VERY INTERESTED TO SEE
IF THE FOREST LIZARDS CAN RUN
AS FAST AS THE URBAN LIZARDS
ON THESE OTHER SUBSTRATES.
Neil: WHILE KRISTIN'S LIZARDS
SPRINTED
ON MINIATURE RACETRACKS,
SHANE SET UP
A LESS TRADITIONAL OLYMPIC EVENT
TO TEST HOW URBAN ANOLES COPE
WITH THE HEAT OF THE CITY.
Shane: REPTILES
ARE COLD-BLOODED ANIMALS,
AND A LOT OF ASPECTS
OF THEIR BIOLOGY
ARE LINKED TO TEMPERATURE.
TO FIGURE OUT HOW HOT A LIZARD
CAN GET BEFORE IT STOPS WORKING,
WE GRADUALLY WARM THAT LIZARD,
AND WE PERIODICALLY FLIP IT
ONTO ITS BACK.
Neil: SHANE ISN'T HURTING
THE LIZARDS.
AS HE SLOWLY HEATS THEM UP,
THEY EVENTUALLY GET TOO HOT
TO RESPOND.
Shane: THE RIGHTING REFLEX
IS SUCH A GOOD TEST
BECAUSE A LIZARD ALWAYS
WANTS TO BE ON ITS FEET.
Neil: SHANE RECORDS
THE TEMPERATURE
AT WHICH THEY CAN NO LONGER
TURN THEMSELVES BACK OVER,
AND THEN HE QUICKLY HELPS
THE LIZARDS COOL BACK DOWN.
AFTER CAPTURING AND TESTING
HUNDREDS OF ANOLES,
IT WAS TIME
FOR SHANE AND KRISTIN
TO COMPARE THE LIZARDS
FROM THE FOREST AND THE CITY.
ON AVERAGE, URBAN LIZARDS WERE
ABLE TO TOLERATE TEMPERATURES
THAT WERE
ONE DEGREE CELSIUS HOTTER
COMPARED TO FOREST LIZARDS.
Kristin: A DIFFERENCE
OF ONE DEGREE CELSIUS
MIGHT NOT SEEM LIKE A LOT,
BUT FOR A LIZARD,
THIS IS A DIFFERENCE
OF BEING ABLE TO BE ACTIVE
ALL DAY LONG
AND HAVE ACCESS TO ALL OF
THOSE MATES AND ALL OF THAT FOOD
THAT YOU OTHERWISE
WOULD HAVE TO GIVE UP
BECAUSE YOU'RE HIDING IN
THE SHADE TRYING TO COOL DOWN.
Neil: THE URBAN LIZARDS ALSO
HAVE AN ADVANTAGE RUNNING
ON THE SLICK SURFACES FOUND
IN THE CITY ENVIRONMENT.
Kristin: THE URBAN LIZARDS
RUN FASTER ON ALL SUBSTRATES,
AND THESE DIFFERENCES
ARE MOST PRONOUNCED
ON THE VERY SMOOTH
VERTICAL SUBSTRATES,
ON THE METAL
AND ON THE PAINTED CONCRETE.
THE ABILITY TO PERFORM WELL
ON THESE SUBSTRATES
HAS REAL IMPLICATIONS FOR
THEIR SURVIVAL IN THIS HABITAT.
Neil: THESE LITTLE LIZARDS
CONTINUE TO SURPRISE SCIENTISTS
WITH THEIR POWERS OF ADAPTATION,
EVEN IN FAST-CHANGING
ENVIRONMENTS.
KRISTIN AND SHANE'S DISCOVERIES
SHOW THAT THE ANOLES'
ANCIENT EVOLUTIONARY PLAYBOOK
STILL HELPS THEM SURVIVE AND
ADAPT, EVEN IN THE MODERN WORLD.
Nate: JUST WHEN WE THOUGHT
OUR JOURNEY WAS OVER,
WE HEARD ABOUT A NEW DISCOVERY
IN THE DOMINICAN REPUBLIC--
A NEW ANOLE SPECIES,
A TRULY BIZARRE LIZARD
THAT HAD CAUGHT SCIENTISTS
COMPLETELY OFF GUARD.
WE HAD TO SEE IT.
ONE OF THE FEW PEOPLE
WHO KNEW WHERE TO FIND IT
WAS LUKE MAHLER, THE SCIENTIST
WHO FIRST DESCRIBED IT.
Luke Mahler:
IT'S AN UNEXPECTED DISCOVERY.
THIS IS A GIANT ANOLE THAT,
THAT LIVES HIGH IN THE TREES
BUT IS STRIKINGLY SIMILAR
TO A GROUP OF LIZARDS
PREVIOUSLY ONLY KNOWN FROM CUBA,
SO THIS, THIS ANOLE POTENTIALLY
REPRESENTS A NEW ECOMORPH,
AND SO WE'RE HERE
TO LOOK FOR IT.
Neil: LUKE TOOK US TO THE PLACE
WHERE HE FIRST SAW
THIS MYSTERIOUS ANOLE.
Luke: YOU GET
THIS SORT OF NEAT SPOT
WHERE THE TREES
ARE DRY FOREST TREES,
BUT THEN YOU START GETTING
THE SPANISH MOSS,
LOTS OF LICHEN.
Nate: I'VE NEVER SEEN
ANY PLACE LIKE THIS.
THIS IS A TOTALLY BIZARRE,
UNIQUE, COOL PLACE.
Neil: I'M "LICHEN"
THIS ENVIRONMENT.
Nate: YEAH.
Luke: OH! THAT'S, THAT'S GOOD!
[LAUGHTER]
Nate: "I'M LICHEN
THIS ENVIRONMENT."
Neil: LUKE TOLD US THAT
OUR BEST CHANCE
OF FINDING THESE LIZARDS
WAS TO SEARCH FOR THEM AT NIGHT
WHILE THEY WERE SLEEPING.
Nate: I WILL FLIP OUT
IF WE SEE THIS LIZARD TONIGHT.
Neil: IS THAT A GUARANTEE?
Nate: THAT I'LL FLIP OUT?
Neil: IS THAT A PROMISE?
Nate: I PROMISE.
I'LL FLIP OUT.
Neil: AWESOME.
I CAN'T WAIT.
Nate: THIS NEW SPECIES WAS
ONE OF THE MOST MYSTERIOUS
LIZARDS IN THE WORLD,
AND WE WANTED TO BE
THE FIRST FILM CREW TO FIND IT.
EASIER SAID THAN DONE.
Luke: YOU GOTTA BE
IN THE RIGHT SPOT, GET LUCKY,
AND BE LOOKING
FOR THE RIGHT THING.
Nate: FROM LUKE'S DESCRIPTION,
WE KNEW WHAT TO LOOK FOR--
A GRAYISH MOSSY-LOOKING LIZARD
SLEEPING
ON A GRAY MOSSY BRANCH.
I'VE NEVER SEEN
SO MANY TARANTULAS.
Luke: WELCOME TO MY WORLD.
[LAUGHTER]
[SIGHS]
Nate: AFTER SPENDING FIVE HOURS
LOOKING AT TWIGS IN THE DARK,
YOU START SEEING THINGS
THAT AREN'T THERE.
I'M PRETTY SLEEPY.
IT HAS BEEN A LONG,
UNSUCCESSFUL NIGHT.
Neil: OTHER THAN
A FEW HUNDRED TARANTULAS
AND A TON OF BUG BITES,
WE HAD NOTHING.
Nate: I THINK WE'RE
GOING TO FIND IT,
JUST NOT TONIGHT.
Neil: WE STILL HAD ONE MORE
NIGHT IN THE DOMINICAN REPUBLIC,
ONE LAST CHANCE
TO BE THE FIRST FILM CREW
TO CAPTURE FOOTAGE
OF THIS NEW SPECIES,
BUT IT WAS STARTING TO FEEL
LIKE A LONG SHOT.
♪
Nate: IT WAS OUR LAST NIGHT
IN THIS REMOTE CORNER
OF THE DOMINICAN REPUBLIC,
OUR LAST CHANCE
TO FIND AND FILM A LIZARD
THAT WAS BRAND-NEW TO SCIENCE.
WE WERE ALL A LITTLE NERVOUS.
Luke: SO, THE GOAL HERE
IS IF YOU SEE A LIZARD
AND IT DOESN'T SEE YOU,
LOOK AWAY FROM IT,
DON'T SCARE IT WITH YOUR LIGHTS,
FLAG IT, RADIO OVER,
LET EVERYBODY KNOW.
♪
Neil: A FEW HOURS GO BY, AND
LUKE GETS A CALL OVER THE RADIO.
Man on radio:
SO, WE GOT AN ANOLE UP HERE.
Luke: ALL RIGHT,
I'LL BE RIGHT OVER.
OKAY, WHICH, WHICH, WHICH TREE?
YEP, THAT'S,
THAT'S ANOLIS LANDESTOYI.
OKAY, WE GOT ONE.
Nate: A BABY?
Luke: WE GOT ONE.
Nate: WHERE IS IT?
Luke: I'LL SHOW YOU.
SO, WE'RE GOING TO BE CAREFUL
NOT TO SPOOK IT.
UP. YOU CAN SEE
THERE'S THAT WHITE SPOT.
Nate: OH, YEAH!
Luke: THAT'S IT.
IT'S A LITTLE JUVIE HANGING
HEAD-DOWN WITH ITS TAIL UP.
Nate: HOW DID YOU SEE THAT?
Neil: WHOA!
IT'S TOTALLY DIFFERENT-LOOKING
FROM, THAN EVERYTHING ELSE
WE'VE SEEN.
Nate: FIRST
ANOLIS LANDESTOYI, MAN!
YEAH!
ALL RIGHT!
SEEING THIS LIZARD
FOR THE FIRST TIME WAS AMAZING,
BUT THEN REALITY HIT.
IT WAS DANGLING FROM A BRANCH
30 FEET OFF THE GROUND,
WAY TOO HIGH FOR US TO FILM.
OUR ONLY CHANCE
WAS TO WAIT UNTIL SUNRISE
AND HOPE THAT IT MOVED LOW
ENOUGH THAT WE COULD CATCH IT.
HEY, I GOT AN IDEA.
I GOT A GREAT IDEA.
LET'S PULL THE CAR OVER HERE
AND NOOSE HIM
FROM ON TOP OF THE CAR.
Neil: WE BOTH GET ON THE ROOF.
NATE'S LOOKING THROUGH THE
CAMERA SO THAT HE CAN GUIDE ME,
BECAUSE I CAN'T SEE
WHAT I'M DOING.
Nate: NO, I THINK
YOU JUST LOST HIM.
YES, YES, YES, YES, YES!
OH! YOU GOT HIM!
[BLEEP] YOU GOT HIM!
YES!
[LAUGHS]
NEIL!
HANDS DOWN,
THE BEST LIZARD CATCH
THAT I'VE EVER SEEN.
Neil: HERE IS ONE OF THE RAREST
ANOLES IN THE WORLD!
[LAUGHTER]
OH, HE'S LIKE A LITTLE DINOSAUR.
Nate: WHAT?
Neil: HE'S TRYING
TO BITE ME HERE.
Nate: OH, MY GOD!
Neil: I'M PRETTY STOKED.
Nate: THIS IS LIKE
THE WHOLE TRIP,
WE'VE BEEN LOOKING
FOR THIS GUY.
VERY, VERY FEW PEOPLE
WHO ARE INTERESTED IN ANOLES
HAVE SEEN THIS LIZARD,
WHICH MAKES IT SUPER SPECIAL
TO GET TO, TO GET TO HOLD.
AS WE HELD THIS NEW SPECIES
AND FILMED IT
CLIMB BACK INTO THE TREE,
WE COULDN'T HELP BUT REMEMBER
THE FIRST LAW OF THE LIZARD
WE LEARNED ON THIS JOURNEY--
EXPECT SURPRISES.
EVEN ON HISPANIOLA,
AN ISLAND WHERE BIOLOGISTS
HAVE WORKED FOR DECADES,
HERE WAS A STRANGE ANOLE,
TOTALLY UNLIKE
ANYTHING ELSE ON THE ISLAND,
THAT NO ONE HAD EVEN NOTICED
UNTIL A FEW YEARS AGO.
Neil: IT REALLY DROVE HOME
HOW LITTLE WE STILL KNOW,
IN MANY WAYS, ABOUT ANOLES.
BUT EVEN SOME
OF THE MOST COMMON SPECIES,
THE ONES THAT SCIENTISTS
HAVE STUDIED FOR DECADES,
THERE ARE STILL THINGS
ABOUT THEIR LIVES
THAT WE JUST DON'T KNOW.
Jonathan: WHEN I GRADUATED
FROM COLLEGE, I SAID TO MYSELF,
"I'M NEVER GOING TO STUDY ANOLES
AGAIN BECAUSE WE KNOW IT ALL."
OF COURSE, THAT WAS NAIVE.
FAR FROM KNOWING IT ALL, WE'VE
BARELY SCRATCHED THE SURFACE.
♪
Nate: NEIL AND I HAD FOLLOWED
THE ANOLE STORY
FOR MORE THAN A YEAR,
FROM CARIBBEAN RAINFORESTS
TO UNIVERSITY LABORATORIES,
FROM TINY BAHAMIAN ISLANDS
TO THE CITY OF MIAMI.
WE STARTED THIS QUEST
THINKING WE UNDERSTOOD
WHY ANOLES WERE SPECIAL,
BUT OUR JOURNEY LEFT US
WITH SOMETHING MORE PROFOUND.
Neil: GOING AND SEEING
THE DIVERSITY OF ANOLES
IN AN ISLAND
LIKE PUERTO RICO,
IT'S LIKE GOING
TO THE LOUVRE IN PARIS
AND APPRECIATING THE ART THERE.
IT'S SOMETHING THAT'S BEAUTIFUL
AND COMPLEX AND FASCINATING,
COMPLETELY OF ITS OWN ACCORD.
♪
Nate: WHEN I WAS A SCIENTIST
STUDYING LIZARDS,
PEOPLE WOULD ALWAYS ASK ME,
"WHY ARE YOU STUDYING LIZARDS?"
AND I THINK THAT IT'S,
IT'S NORMAL TO BE SKEPTICAL.
IT'S HARD TO UNDERSTAND WHY
IT COULD POSSIBLY BE IMPORTANT
TO DEDICATE ALL THIS EFFORT
INTO UNDERSTANDING HOW
THESE LIZARDS LIVE THEIR LIVES.
BUT LIFE ON EARTH
IS INCREDIBLY COMPLICATED,
AND UNDERSTANDING THE RULES
THAT GENERATED THAT DIVERSITY
IS FUNDAMENTAL TO UNDERSTANDING
WHERE WE FIT
INTO THE BIGGER PICTURE,
AND VERY FEW OTHER ORGANISMS
HAVE TAUGHT US AS MUCH
ABOUT THOSE RULES AS ANOLES.
♪
♪