Woolly Mammoth Genome Sequenced
A team of international scientists has published the genome of the Woolly Mammoth (M. primigenius). Their work has been published in the latest edition of the journal “Current Biology”.
The genome is an organism’s complete set of DNA, the information needed to build, maintain and sustain an organism. The genome includes all the genes involved with coding proteins and all the non-coding elements of the DNA or RNA. In the case of the Woolly Mammoth, the genome is very long, consisting of several billion base pairs or nucleotides. The four chemical building blocks of DNA are adenine (A), cytosine (C), guanine (G) and thymine (T). The G’s always pair up with the C’s, whilst the adenine always links up with the thymine (A’s to T’s).
Scientists have Mapped the Genome of the Woolly Mammoth
Picture Credit: Swedish Museum of Natural History/Current Biology
In fact, the complete genome of two Woolly Mammoths have been sequenced. The first to be sequenced comes from a Mammoth that died just 4,300 years ago on the remote Wrangel Island in the Arctic Ocean. Wrangel island is believed to where the very last Mammoths roamed. The second Mammoth to have its genome sequenced came from north-eastern Siberia and dates from approximately 44,800 years ago.
This research is not linked to the “de-extinction” of the Woolly Mammoth but a better mapped genome will prove very helpful to geneticists with plans to breed Asian elephants with Woolly Mammoth traits. The research was undertaken to help scientists to understand better the stress the last population of Woolly Mammoths was under prior to the extinction of this species. The genome reveals a significant amount of inbreeding taking place in the last of the Mammoths. A sign of a reducing population. The genome from the Late Pleistocene specimen, when compared to the much more recent Wrangel Island genome, is helping scientists to calibrate the molecular clock for this ancient elephant.
What is a Molecular Clock?
The molecular clock for an organism is an extremely simple but useful concept. It is assumed that the rate of mutation (genetic change) is relatively constant, if this is the case, then by comparing the DNA of two organisms that died at very different geological times will provide scientists with an accurate method of dating those specimens. The study shows that over the history of the species, the Woolly Mammoth population was reduced dramatically (genetic variation declined) on at least two occasions. A decline in the genetic variation of an organism could be an indicator of population decline. Although this is not always the case, for example, the species of extant great ape with the least genetic variation is also the most numerous on our planet. That species is our own – Homo sapiens.
For museum quality models of Woolly Mammoths and other Ice Age creatures for use in schools: Ice Age Models