Genomic and morphometric data used in a demographic study of Coragyps vultures

The New World Vulture [Coragyps] occidentalis (L. Miller, 1909) is one of
many species that were extinct by the end of the Pleistocene. To
understand its evolutionary history we sequenced the genome of a
14,000-year-old [Coragyps] occidentalis found associated with
megaherbivores in the Peruvian Andes. occidentalis has been viewed as the
ancestor, or possibly sister, to the extant Black Vulture Coragyps
atratus, but genomic data shows occidentalis to be deeply nested within
the South American clade of atratus. Coragyps atratus inhabits lowlands,
but the fossil record indicates that occidentalis mostly occupied high
elevations. Our results suggest that occidentalis evolved from a
population of atratus in southwestern South America that colonized the
High Andes 300 to 400 kya. The morphological and morphometric differences
between occidentalis and atratus may thus be explained by ecological
diversification following the natural selection imposed by this new and
extreme, high-elevation environment. The sudden evolution of a population
with significantly larger body size and different anatomical proportions
than atratus thus constitutes an example of punctuated evolution.