Evolution: Ancient proteins unravel back
story of ‘strange’ mammals *IMAGES*
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Nature
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Evolution
Embargo
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London: Wednesday 18 March 2015 18:00 (GMT)
New York: Wednesday 18 March 2015 14:00 (EDT)
Tokyo: Thursday 19 March 2015 03:00 (JST)
Sydney: Thursday 19 March 2015 05:00 (AEDT)
The evolutionary history of South American native ungulates, which Darwin called the
strangest animals ever discovered, is revealed in Nature this week. The study, which focuses
on ancient proteins, also highlights the potential of proteomics to greatly enhance our
understanding of the history of life on earth.
The South American native ungulates were a large, diverse, group of mammals that included
Macrauchenia, a leggy, long-necked tapir-like animal and Toxodon, a beast with a
rhinoceros-like body and a hippopotamus-like head. Despite their relatively recent extinction
we know little about their evolutionary back story.
Ian Barnes and colleagues show that Macrauchenia and Toxodon are descended from an
ancient group of placental mammals called the condylarths and are a sister group to
Perissodactyla, the collection of animals that includes horses, tapirs and rhinos. They are not,
as some had suggested, related to Afrotheria, the group of animals, of African origin, that
includes aardvarks and elephants.
The team arrived at their conclusions by studying collagen, a common, structural protein
found in connective tissue. Collagen is a particularly durable protein that can sometimes be
recovered from bone long after any DNA has degraded. Thus, the study of ancient proteins is
an attractive method for unravelling the evolutionary past because it has the potential to reach
much further back in time than can studies of ancient DNA.
Article and author details
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Ancient proteins resolve the evolutionary history of Darwin's South
American ungulates
Corresponding Author
Ian Barnes (Natural History Museum, London, UK)
Email: I.Barnes@nhm.ac.uk, Tel: +44 7912 093181
DOI
10.1038/nature14249
Online paper*
http://dx.doi.org/10.1038/nature14249
* Please link to the article in online versions of your report (the URL will go live after the embargo
ends).
IMAGES
Image 1
Caption: Macrauchenia, a humpless camel with an extended snout.
Credit: Illustration by Peter Schouten from the forthcoming book "Biggest, Fiercest,
Strangest" W. Norton Publishers (in production)
Image 2
Caption: The hippo-like Toxodon.
Credit: Illustration by Peter Schouten from the forthcoming book "Biggest, Fiercest,
Strangest" W. Norton Publishers (in production)