High incidence of cervical ribs indicates vulnerable condition in Late Pleistocene woolly rhinoceroses.

ABSTRACT: Mammals as a rule have seven cervical vertebrae, a number that remains remarkably constant. Changes of this number are associated with major congenital abnormalities (pleiotropic effects) that are, at least in humans, strongly selected against. Recently, it was found that Late Pleistocene mammoths (Mammuthus primigenius) from the North Sea have an unusually high incidence of abnormal cervical vertebral numbers, approximately ten times higher than that of extant elephants. Abnormal numbers were due to the presence of large cervical ribs on the seventh vertebra, indicating a homeotic change from a cervical rib-less vertebra into a thoracic rib-bearing vertebra. The high incidence of cervical ribs indicates a vulnerable condition and is thought to be due to inbreeding and adverse condi

SUBMITTER: van der Geer AAE 

PROVIDER: S-EPMC5580387 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature