Wooly Mammoths Experienced 'Genomic Meltdown' Before Extinction

A new study details the severe evolutionary changes that affected the wooly mammoth shortly before it went extinct. Among those changes, researchers have found that wooly mammoths experienced a great reduction in their ability to smell, as well as changes that produced a satin fur coat and other things. The changes took place in a small popular of wooly mammoths living in isolation on Wrangel island.

The study was recently published in the journal PLOS, where researchers detail substantial genetic changes experienced by wooly mammoths 'just prior' to the species extinction. These changes are referred to as a 'genomic meltdown,' and include things like mutations, deletions, and retro genes in the creature's genetic code.

Researchers found this in genetic material acquired from a 4300-year-old specimen and compared it to a specimen that dates back 45,000 years to a time when the wooly mammoth was plentiful and healthy. The younger specimen comes from Wrangel island, where researchers say a small population was present.

According to the study, 'These extreme differences in effective population size offer a rare opportunity to test nearly neutral models of genome architecture evolution within a single species.' The low population, it turns out, led to a growing number of 'detrimental mutations.'

The genetic data indicate the wooly mammoths who lived on this island close to extinct had unusual shiny coats and decreased olfactory senses, and more. These genetic changes may also have influenced mating selection, further reinforcing the eventual 'genomic meltdown.'

SOURCE: PLOS