Phylogenomic data analyses provide evidence that Xenarthra and Sfrotheria are sister groups

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift


The phylogenetic positions of the 4 clades, Euarchontoglires, Laurasiatheria, Afrotheria, and Xenarthra, have been major issues in the recent discussion of basal relationships among placental mammals. However, despite considerable efforts these relationships, crucial to the understanding of eutherian evolution and biogeography, have remained essentially unresolved. Euarchontoglires and Laurasiatheria are generally joined into a common clade (Boreoeutheria), whereas the position of Afrotheria and Xenarthra relative to Boreoeutheria has been equivocal in spite of the use of comprehensive amounts of nuclear encoded sequences or the application of genome-level characters such as retroposons. The probable reason for this uncertainty is that the divergences took place long time ago and within a narrow temporal window, leaving only short common branches. With the aim of further examining basal eutherian relationships, we have collected conserved protein-coding sequences from 11 placental mammals, a marsupial and a bird, whose nuclear genomes have been largely sequenced. The length of the alignment of homologous sequences representing each individual species is 2,168,859 nt. This number of sites, representing 2840 protein-coding genes, exceeds by a considerable margin that of any previous study. The phylogenetic analysis joined Xenarthra and Afrotheria on a common branch, Attantogenata. This topology was found to fit the data significantly better than the alternative trees.


  • Björn Hallström
  • Morgan Kullberg
  • Maria Nilsson
  • Axel Janke
Enheter & grupper

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Biologiska vetenskaper


Sidor (från-till)2059-2068
TidskriftMolecular biology and evolution
Utgåva nummer9
StatusPublished - 2007
Peer review utfördJa

Relaterad forskningsoutput

Björn Hallström, 2010, 116 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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