darwin collection

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When Charles Darwin was off observing wildlife in the Galápagos Islands, he wasn’t just looking at finches. In fact, one of the most striking creatures that Darwin found was the Marine Iguana (Amblyrhynchus cristatus). To Darwin, this species was strikingly…stupid.

Marine Iguanas are necessarily dumb, but when Darwin and his fellow shipmates reached the Galápagos, the iguana species was so far removed from human contact that it didn’t consider them a threat. One of my favorite Darwin anecdotes is about the famed naturalist repeatedly throwing a single iguana into the ocean, only to have it swim right back to rest in the same place.

These are huge, huge lizards, reaching over a meter in length, so the idea of one being tossed into the sea is a bit of a strange one. It really does make one wonder what other animal species might be like without the constant threat of predation or disturbance.

Photo credit: Ash Boudrie

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In vitro fertilization (IVF) has been used successfully in many animals — including, notably, humans — for decades. But despite numerous attempts, scientists had never been able to figure out IVF for dogs. 

This year, for the first time, seven puppies (five beagles and two “bockers,” or beagle-cocker spaniel mixes) were born through IVF. That’s cool. And cute. And also very exciting for the people trying to save other canine species that are in decline because of habitat destrcution:

ISLAND FOX, Urocyon littoralis (Southern California)
~4000 left
They live on only six of the eight Channel Islands (less than 400 square miles).

ETHIOPIAN WOLF, Canis simensis (Ethiopian Highlands)
360 - 440 adults left
The Ethiopian wolf sometimes team up with monkeys to hunt alpine rodents.

AFRICAN WILD DOGLycaon pictus (from Algeria to South Africa)
~5,000 left
They hunt antelope by chasing them to exhaustion. 

RED WOLF, Canis Rufus (North Carolina)
~150 left

Their population once fell to just 14 individuals.

MANED WOLFChrysocyon brachyurus (central South America)
~17,000 left
Maned wolves need wide uninterrupted territory to survive.

DHOLECuon alpinus (China, India, Southeast Asia)
4,500-10,500 left
These pack hunters use “whistles” to communicate with one another while hunting much larger prey. 

DARWIN’S FOXLycalopex fulvipes (Chile)
less than 250 left
So-called because Darwin collected a specimen in 1834. 200 of the remaining population live on on Chiloé Island.

MEXICAN GRAY WOLFCanis lupus baileyi (Mexico, the southeastern US)
~360 left
All the Mexican gray wolves alive today are all descendants of five wolves captured in 1973.

Currently, efforts to increase these species rely on natural breeding programs. The Smithsonian’s maned wolf breeding program ships males from South America to their facility in Front Royal, Virginia. It would be great if they could just ship sperm. And using samples collected from multiple individuals could greatly increase the genetic diversity of a population, instead of relying on a few captive mating pairs. Exciting!

When Darwin first noted his famous finches in the Galapagos, he didn’t know that they were all finches. Darwin himself was not an expert ornithologist, and he was only going off of the characteristics that he knew. As far he was concerned, birds with the kind of beak seen above were warblers, so that is what he decided that these were.

Turns out, ‘Darwin’s assorted birds’ all became known as Darwin’s finches once a more experienced eye got a look at them. The finches above are known as Green Warbler-Finches (Certhidea olivacea). They do share many characteristics with warblers, so I suppose we can forgive Darwin his confusion.

Photo credit: Ash Boudrie

Study Finds Relationship Between Glyptodonts, Modern Armadillos

New research using a novel technique to recover ancient DNA reveals that the evolutionary history of glyptodonts—huge, armored mammals that went extinct in the Americas at the end of the last ice age—is unexpectedly brief.

The work, published this week in the journal Current Biology by an international team of researchers, confirms that glyptodonts likely originated less than 35 million years ago from ancestors within lineages leading directly to one of the modern armadillo families.

Numerous species of glyptodonts lived in dense forests, open grasslands, and a variety of other ecosystems, occupying a range that stretched from what is now the southern part of the United States to the Patagonia region of South America.

“Although their disappearance has been blamed on human depredation as well as climate change, some species persisted into the early part of the modern epoch, long after the disappearance of mammoths and saber-toothed cats,“ saidRoss D.E. MacPhee, an author on the study and curator in the Museum’s Department of Mammalogy. "Like the loss of giant ground sloths, mastodons, and dozens of other remarkable mammalian species, the precise cause of the New World megafaunal extinctions remains uncertain.”

Although scientists including Charles Darwin collected partial remains of glyptodonts in the early 19th century, at first nobody knew what kind of mammal they represented. It was eventually accepted that glyptodonts must be related in some way to armadillos, the only other New World mammals to develop a protective bony shell. However, because of the many physical differences between these two groups, most paleontologists have held the view that they must have separated very early in their evolutionary history.

To try and clarify this poorly understood history, researchers Frédéric Delsuc of the French National Center for Scientific Research at the University of Montpellier and Hendrik Poinar of McMaster University worked alongside MacPhee to learn what genetic information on these ancient armored animals could reveal.

As is often the case in ancient DNA investigations, fossil genomic material is poorly preserved, and only one sample worked—a carapace fragment of an undetermined species of Doedicurus, a gigantic glyptodont that lived until about 10,000 years ago. Using a novel approach to recover genetic information from ancient specimens, the team successfully assembled the complete mitochondrial genome of Doedicurus and compared it to that of all modern xenarthrans, a group of mammals including armadillos, sloths, and anteaters.

The researchers found that instead of representing a very early, independent branch of armored xenarthrans, glyptodonts likely had a much later origin, from ancestors within lineages leading to the modern armadillo family Chlamyphoridae.

More surprising still, the study finds that the closest relatives of glyptodonts—some species of which may have weighed 2 tons or more—include not only the giant armadillo (Priodontes maximus), which can weigh up to 25 pounds, but also the 4-ounce pink fairy armadillo, or pichiciego (Chlamyphorus truncatus).

“Contrary to what is generally assumed about the distinctiveness of glyptodonts, our analyses indicate that they originated only some 35 million years ago, well within the armadillo radiation,” Delsuc said. “Taxonomically, they should be regarded as no more than another subfamily of armadillos, which we can call Glyptodontinae.”

This post was originally published on the Museum blog. 

Happy Birthday to Charles Darwin.

I know we don’t often feature things from the Rare Book collection but I thought it would be a good time to show a letter, hand written by Darwin, from our collection.

© The Field Museum, GN90989d and GN90990d

October 31, 1868 letter from (Charles) C. Darwin to B.D. Walsh of Rock Island Illinois. Darwin was interested in American periodical cicadas and states his opinion on 13 and 17 year cicadas. Front and back of letter.

Scan of original document.

This Fossil Friday is all in the family…the armadillo family, that is! 

This is Panochthus frenzelianus, a giant glyptodont that lived in South America, just before the extinction of the glyptodonts, at the end of the last ice age, about 30,000 years ago. Some glyptodonts grew to be over 10 feet long and may have weighed as much as a ton, including the shell. 

Although scientists including Charles Darwin collected partial remains of glyptodonts in the early 19th century, at first nobody knew what kind of mammal they represented. It was eventually accepted that glyptodonts must be related in some way to armadillos, the only other New World mammals to develop a protective bony shell. However, because of the many physical differences between these two groups, most paleontologists have held the view that they must have separated very early in their evolutionary history.

Just this week, new research by an international team of researchers, including Ross MacPhee from AMNH, that used a novel technique to recover ancient DNA revealed that instead of representing a very early, independent branch of armored xenarthrans, glyptodonts likely had a much later origin, from ancestors within lineages leading to the modern armadillo family Chlamyphoridae.

“Contrary to what is generally assumed about the distinctiveness of glyptodonts, our analyses indicate that they originated only some 35 million years ago, well within the armadillo radiation,” said researcher Frédéric Delsuc of the French National Center for Scientific Research. “Taxonomically, they should be regarded as no more than another subfamily of armadillos, which we can call Glyptodontinae.”

Learn more about this new research

all songs that remind me of myself

the kids don’t stand a chance / vampire weekend

be calm / fun.

sarah smiles / panic! at the disco

radar detector / darwin deez

oh no! / marina and the diamonds

please be patient with me / wilco

rosie / the kooks

no hope / the vaccines

arabella / arctic monkeys

here comes the anxiety / the wombats

don’t save me / haim

hard out here / lily allen

the purple bottle / animal collective

trying to be cool / phoenix

i wanna get better / bleachers

wannabe / spice girls

rill rill / sleigh bells

waves / electric guest

who needs you / the orwells

monday morning / death cab for cutie

like or like like / miniature tigers

pizza party / l'homme run

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