Shelf Life 16: Tales From the Cryptic Species

Shelf Life #16 - Tales From the Cryptic Species - Visual Cue Transcript

[PLUCKING STRINGS]

A woman walks through a dimly lit room and sits down at a desk.

EVON HEKKALA: I like to think of myself as a creative thinker about museum collections.

She reaches to turn on a light...

[SOUND OF SWITCH, ELECTRIC SIZZLE]

A network of circles containing natural history specimens populates across the screen. A drawer containing a crocodile skull pulls down from the top of the screen.

HEKKALA: I was doing my dissertation research on crocodiles,

Hands in black rubber gloves hold a tray of sampling instruments, and pull open a drawer with a large crocodile skull.

HEKKALA: and I started to collect data.

[SCRAPING AND SCRATCHING]

Hekkala scrapes small samples from various crocodile skull specimens, and puts them into plastic vials.

HEKKALA: And as I started collecting DNA,

Seven different crocodiles appear at different spots over a satellite map of Africa.

HEKKALA: I realized that there were a lot of places where you couldn't get samples anymore because crocodiles had gone extinct in those sites.

Four of the crocodiles fade into white silhouettes. The others disappear from the map.

HEKKALA: And so I thought, "Maybe I can use museum specimens to fill in some of these gaps."

Circles containing different crocodile specimens pop up. Lines are drawn between the silhouettes and specimens.

[STEAM WHISTLE BLOWS, WATER CHURNS]

A steamship crosses the screen. A red line traces the route of the Congo expedition over mainland Africa. Map text reads, "Congo Expedition of the American Museum of Natural History. May 1909 to November 1915."

HEKKALA: I found that there was this expedition to the Congo from 1909 to 1915,

Archival images of expedition leader James Chapin standing in a pith helmet and sitting next to a tent are superimposed on the map.

HEKKALA: conducted by the American Museum of Natural History.

Different colored circles containing archival images of crocodile skulls pop up across the map.

HEKKALA: And those explorers had collected crocodile specimens from the Upper Congo.

Tweezers pull a tiny sample from a crocodile specimen.

HEKKALA: I extracted samples

Animated DNA helix spins and many Gs, As, Ts, and Cs of various colors move across the screen.

HEKKALA: and I was dumbfounded when I looked at the DNA sequence.

Evon Hekkala holds a crocodile skull in the Herpetology collections, and looks at camera.

HEKKALA: I'm Evon Hekkala, and I'm a research associate at the American Museum of Natural History.

[MUSIC PLAYS]

Shelf Life title sequence. Specimens and artifacts from the Museum's collections fade in and out.

[MUSIC PLAYS]

Old book opens to the title page of Linnaeus's Systema Naturae. Species names on specimen tags, file cards, and DNA sample vials.

JOEL CRACRAFT: Scientists have named and described approximately one and a half million species of organisms.

Curator Joel Cracraft speaks in Ornithology collections room.

CRACRAFT: Yet, everybody agrees that that is a tiny portion of the biodiversity that's out there.

Cracraft stands in front of specimen cabinets.

CRACRAFT: I'm Joel Cracraft. I'm a curator of ornithology here at the American Museum of Natural History.

Black and white archival images of Congo rainforest.

CRACRAFT: The knowledge that we have about the rainforests around the world has been basically built up over the last 100 years or more of exploration.

Evon Hekkala pulls a crocodile skull out of a drawer in the Herpetology collection.

CRACRAFT: But now, new, younger scientists are going out and they are looking at diversity in these forests from a genetic point of view.

Hekkala points at a small river on a large, old map of Africa.

HEKKALA: So, this site right here—Faradje—is where they collected two specimens of crocodiles on either side of this little river.

Close-ups of two crocodile specimens with numbered tags.

HEKKALA: And it turned out that one specimen had one DNA sequence, and the other specimen had another DNA sequence.

Hekkala sits at desk next to two crocodile skulls.

HEKKALA: And they were completely different.

The phrase "cryptic species" is revealed from behind a tangle of red lines.

HEKKALA: And I started thinking, "There must be a cryptic species here."

Two butterflies appear in silhouette with species names—Perichares poaceaphaga and Perichares geonomaphaga.

CRACRAFT: Two very distinct species can look exactly the same.

Silhouettes dissolve into photos of butterflies that look extremely similar. Then, as genetic sequence appears in Gs, Cs, As, and Ts, a blue circle appears behind one butterfly, and a yellow circle behind the other.

CRACRAFT: But when you look at them genetically then you find out that, in fact, they're very different.

Cracraft speaks in Ornithology collections room.

CRACRAFT: And so, we call those things cryptic species.

Silhouettes of various animals – a fish, a cat, a snake, etc. – appear in colored circles over an archival photo of the Congo rainforest.

CRACRAFT: And we are finding that we've underestimated species diversity in virtually all organisms in these forests.

The species name "Crocodylus niloticus" appears in a black circle, on top of a twisting strand of DNA. It is surrounded by images of crocodiles.

HEKKALA: It turned out that one specimen represents the Nile crocodile species that we all know and love from the Nile.

The black circle splits in two—Crocodylus niloticus goes off to the right, and a new black circle appears with the species name Crocodylus suchus and other images of crocodiles.

HEKKALA: And the other represents a completely separate species of crocodiles. In fact, they're so distinct, they're not even each other's closest relatives.

Hekkala sits at desk next to two crocodile skulls.

HEKKALA: They haven't exchanged genes in millions of years.

Camera pushes in to Hekkala standing over an old field notebook in the Herpetology archives.

[PLUCKING STRINGS]

HEKKALA: Once I started looking into the documentation that went along with those crocodiles,

Close-up of Hekkala's finger pointing to the word "crocodile" in old Lang-Chapin field notebook. Hekkala reads through other old field notebooks.

HEKKALA: I realized there must be other specimens from their expedition that also represent cryptic species.

Hekkala speaks in front of large map of Africa.

HEKKALA: This is a great opportunity for species discovery.

Tortoise shell and bones in plastic container.

HEKKALA: So, we started looking at tortoises.

Drawer pulls open to reveal monitor skull and specimen boxes.

HEKKALA: And we started looking at monitor lizards.

Hekkala speaks in front of large map of Africa.

HEKKALA: We started finding similar patterns there.

Series of archival images with pangolin, okapi, and elephant shrew.

HEKKALA: We were planning on looking into pangolins, the okapi, elephant shrews...

Hekkala speaks in front of large map of Africa.

HEKKALA: But the one that sort of jumped out at me right away was the African leopard.

Leopard jaw, coat, and specimen tag reading "The American Museum of Natural History" No. 52025 [male symbol] Date, 24 Nov 1913. Panthera pardus iturensis."

HEKKALA: Everyone's assumed that they're all one species recently,

Red specimen tag reads "American Museum 52025, Felis pardus iturensis, TYPE SPECIMEN" Drawer with leopard skull surrounded by a collage of field notes, maps, and a photograph of Herbert Lang. Circles appear with black and white, close up images of leopard coat patterns.

HEKKALA: but in the Lang-Chapin field notes, they describe differences in the coat texture, and pattern, differences in the distribution and the sizes.

The skull of a leopard rotates, as the text "Panthera pardus" appears.

HEKKALA: And so, we thought that would be a really good target species.

Hekkala speaks in front of large map of Africa.

HEKKALA: The most exciting thing with what we found in the leopard data, and it's also the most concerning,

Drawer with leopard skull and field notes. Molecular data diagrams and spreadsheets appear around the skull. A circle expands out with an aerial view of the Congo rainforest, an archival photo of a leopard, and a map indicating a small area in the Congo basin.

HEKKALA: is that our molecular data suggests that one of the leopard subspecies is found only in a tiny little pocket in the forest in the Upper Congo.

Hekkala speaks in front of large map of Africa.

HEKKALA: If we lose this unique little slice of genetic diversity, we're actually losing global biodiversity.

Cracraft speaks in Ornithology collections room.

CRACRAFT: Biological diversity is many things to many people.

A large iguana crawls across rocky landscape. A flower waves in the wind. A flock of flamingoes stand in a lake. A monkey sits in a treetop.

CRACRAFT: One of it is the obvious—how many different kinds of organisms are there out there?

A pipette squirts liquid into a test tube.

CRACRAFT: Another way to look at it is how much genetic diversity does a habitat contain.

Camera trap images of leopards moving through the forest.

HEKKALA: Having a distinct genetic identity may not necessarily mean that you're a distinct species. But having a distinct characteristic of your DNA may be incredibly important because more variation tends to be better in the face of a changing world.

Hekkala speaks in front of large map of Africa.

HEKKALA: And when populations get small and isolated,

Camera trap series of a leopard walking through the forest.

HEKKALA: they don't have the necessary ability to be resilient in the face of change.

Cracraft speaks in Ornithology collections room.

CRACRAFT: The pressures on the forest have increased dramatically.

Hekkala pulls a skull from a drawer in the Herpetology collections and walks towards camera.

CRACRAFT: Knowing what's out there is the first step in saving what's out there.

Hands in black latex gloves scrape a small sample off of a crocodile skull and put it in a vial.

CRACRAFT: And managing the genetic diversity is a key component

Cracraft speaks in Ornithology collections room.

CRACRAFT: to managing endangered species everywhere in the world right now.

Hekkala examines a crocodile specimen in a jar.

HEKKALA: One of the reasons that these historical collections are so valuable and important is because

Camera rises through the treetops of the Congo rainforest. Aerial view as flies over the Congo river towards a thunderstorm. Elephants wade in a shallow pool, surrounded by vegetation.

HEKKALA: today conflict, deforestation, habitat loss, poaching—these are all devastating the flora and fauna of the Congo basin.

Close up of fingers picking up a specimen tag reading "American Museum of Natural History, 10081" that rests on a crocodile skull.

HEKKALA: So, these specimens represent an irreplaceable resource that can never be reacquired.

Close up of the specimen tag reading "TYPE, The American Museum of Natural History, 52025, Panthera pardus iturensis [male symbol], Congo: Niapu. Nov. 24 1913, Lang-Chapin Congo Exp." Hekkala holds a jar containing a crocodile specimen.

[MUSIC PLAYS]

Credits roll.