Mammoth Meltdown!

(Wooly mammoths near the Somme River, AMNH mural. Credit: Charles R. Knight, Public Domain, Wikimedia Commons)

In a previous lecture, we examined the dangers of inbreeding and the potential for the accumulation of detrimental and lethal alleles. Here is an example of this.

In a study conducted by Rebekah Rogers and Montgomery Slatkin of the University of California, Berkeley, the genomes of two different mammoths were analyzed. One sample was taken from a mammoth who lived 45, 000 years ago to one that lived 4, 300 years ago. What they found was shocking. It’s important to note that 45, 000 years ago, mammoths were plentiful. This abundance translated to genetic diversity within this species. The more recent sample, however, came from a mammoth who lived on an isolated island with about 300 other mammoths; they constituted one of the last surviving members of this species. Thus, by comparing the two genomes, the younger mammoth was found to have a significant number of harmful mutations, including a loss of olfactory receptors, urine proteins used in social status and mating, and a translucent coat. It was concluded that inbreeding amongst this small population led to an accumulation of these lethal alleles that mathematical models suggested were too extreme to have arose from other sources. 

Among the main takeaways from this article was validation of the negative effects of consanguineous mating, dangers of using small isolated samples in conservation efforts, and a warning for researchers trying to bring back the woolly mammoth to watch out for an accumulation of harmful mutations in their samples. I particularly was intrigued by the insight into the challenges faced by conversationalists working with dwindling populations. 

Here is the article, which contains a link to the article (which includes a link to the actual paper it was based on): 

Read more at: https://phys.org/news/2017-03-woolly-mammoths-experienced-genomic-meltdown.html#jCp