Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates

No large group of recently extinct placental mammals remains as evolutionarily cryptic as the approximately 280 genera grouped as 'South American native ungulates'. To Charles Darwin, who first collected their remains, they included perhaps the 'strangest animal[s] ever discovered...

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Autores principales: Reguero, Marcelo Alfredo, Gelfo, Javier Nicolás
Formato: Articulo
Lenguaje:Inglés
Publicado: 2015
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/127194
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id I19-R120-10915-127194
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Paleontología
Ancient DNA
Macrauchenia
Toxodon
Ungulate
Notoungulata
Laurasiatheria
Afrotheria
Litopterna
Biology
Zoology
spellingShingle Paleontología
Ancient DNA
Macrauchenia
Toxodon
Ungulate
Notoungulata
Laurasiatheria
Afrotheria
Litopterna
Biology
Zoology
Reguero, Marcelo Alfredo
Gelfo, Javier Nicolás
Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates
topic_facet Paleontología
Ancient DNA
Macrauchenia
Toxodon
Ungulate
Notoungulata
Laurasiatheria
Afrotheria
Litopterna
Biology
Zoology
description No large group of recently extinct placental mammals remains as evolutionarily cryptic as the approximately 280 genera grouped as 'South American native ungulates'. To Charles Darwin, who first collected their remains, they included perhaps the 'strangest animal[s] ever discovered'. Today, much like 180 years ago, it is no clearer whether they had one origin or several, arose before or after the Cretaceous/Palaeogene transition 66.2 million years ago, or are more likely to belong with the elephants and sirenians of superorder Afrotheria than with the euungulates (cattle, horses, and allies) of superorder Laurasiatheria. Morphology-based analyses have proved unconvincing because convergences are pervasive among unrelated ungulate-like placentals. Approaches using ancient DNA have also been unsuccessful, probably because of rapid DNA degradation in semitropical and temperate deposits. Here we apply proteomic analysis to screen bone samples of the Late Quaternary South American native ungulate taxa Toxodon (Notoungulata) and Macrauchenia (Litopterna) for phylogenetically informative protein sequences. For each ungulate, we obtain approximately 90% direct sequence coverage of type I collagen α1- and α2-chains, representing approximately 900 of 1,140 amino-acid residues for each subunit. A phylogeny is estimated from an alignment of these fossil sequences with collagen (I) gene transcripts from available mammalian genomes or mass spectrometrically derived sequence data obtained for this study. The resulting consensus tree agrees well with recent higher-level mammalian phylogenies. Toxodon and Macrauchenia form a monophyletic group whose sister taxon is not Afrotheria or any of its constituent clades as recently claimed, but instead crown Perissodactyla (horses, tapirs, and rhinoceroses). These results are consistent with the origin of at least some South American native ungulates from 'condylarths', a paraphyletic assembly of archaic placentals. With ongoing improvements in instrumentation and analytical procedures, proteomics may produce a revolution in systematics such as that achieved by genomics, but with the possibility of reaching much further back in time.
format Articulo
Articulo
author Reguero, Marcelo Alfredo
Gelfo, Javier Nicolás
author_facet Reguero, Marcelo Alfredo
Gelfo, Javier Nicolás
author_sort Reguero, Marcelo Alfredo
title Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates
title_short Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates
title_full Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates
title_fullStr Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates
title_full_unstemmed Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates
title_sort ancient proteins resolve the evolutionary history of darwin’s south american ungulates
publishDate 2015
url http://sedici.unlp.edu.ar/handle/10915/127194
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AT gelfojaviernicolas ancientproteinsresolvetheevolutionaryhistoryofdarwinssouthamericanungulates
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