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Life copes: The horses that adapted to massive climate change in just 800 years

Posted By Joanne Nova On November 27, 2015 @ 3:02 am In Biology,Global Warming | Comments Disabled

Biology, adaption, climate change, horse

In evolutionary terms, it’s a blink. Around 1200-1400AD a bunch of people bought a few domestic horses to far east freezing Siberia, where the temperature sometimes falls below -70. Somehow the horses have already become physiologically and genetically well adapted to the extreme climate. The panic-merchants would have us believe that the climate is changing “faster than evolution”, but biology and genes turn out to be amazingly flexible. (Who knows, maybe 4 million years of swinging ice ages has that effect on gene pools?)

DNA studies revealed that these horses were all derived from distant domestic horses, even though wild unrelated horses lived in the region til 5,000 years ago. This is pretty spectacular.

Dr. Ludovic Orlando: “This is truly amazing as it implies that all traits now seen in Yakutian horses are the product of very fast adaptive processes, taking place in about 800 years. This represents about a hundred generations for horses. That shows how fast evolution can go when selective pressures for survival are as strong as in the extreme environment of Yakutia.”

Analyzing the genomes shows that it’s not driven by mutations in genes as much as by changes to the regulatory parts of the genome. In other words, the instructions about the instructions changed. Useful genes (like fur) get expressed more often, less useful ones become dormant. Imagine all mammal species, say, carry a similar toolkit. It’s not a question of inventing fur, just of making it thicker, or stick around longer. A bit like building houses — if we change the instructions – the same tools and types of materials can make good houses in both Darwin and Greenland. A brick is a brick, but you can have lots of bricks, high walls, thicker walls, and empty spaces. A small change in the plans makes all the difference.

Humans, mammoths and horses appear to have separately picked up changes in things like shivering, or fur thickness that help them adapt to the extreme cold. It’s called “convergent” evolution.

It doesn’t prove that all species will adapt to big changes, but it shows that things are (yet again) a lot better than the apocalyptic scenarios suggest. It’s possible that life can adapt.

To believe that a slight climate-change,
Could destroy life on Earth is most strange,
When in fact what we find,
Is that beasts and mankind,
Can adapt through a vast climate range.

                          — Ruairi

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Adapting to -70 degrees in Siberia: a tale of Yakutian horses

FROM COLD TO COLDER

From an evolutionary perspective it happened almost overnight. In less than 800 years Yakutian horses adapted to temperatures of -70 degrees found in the extreme environments of eastern Siberia. The adaptation mechanisms involved the same genes found in humans as well as the extinct wooly mammoth.

In a new scientific study, the comparison of the complete genomes of nine living and two ancient Yakutian horses from Far-East Siberia with a large genome panel of 27 domesticated horses reveals that the current population of Yakutian horses was founded following the migration of the Yakut people into the region in the 13-15th century AD. Yakutian horses, thus, developed their striking adaptations to the extreme cold climate present in the region in less than 800 years. This is one of the fastest examples of adaptation within mammals.

A horse-centered lifestyle

Horses have been essential to the survival and development of the Yakut people, who migrated into the Far-East Siberia in the 13-15th century AD, probably from Mongolia. There, Yakut people developed an economy almost entirely based on horses. Horses were indeed key for communication and keeping population contact within a territory slightly larger than Argentina, and with 40 % of its surface area situated north of the Arctic Circle. Horse meat and hide have also revealed crucial for surviving extremely cold winters, with temperatures occasionally dropping below -70C.

Horses have been present in Yakutia for a long time as 30,000 year-old Late Pleistocene fossils from the region show. Yet, Dr. Ludovic Orlando and his team now reveal that ancient horses of this region were not the ancestors of the present-day Yakutian horses.

A divergence as deep as the origin of modern humans

The genome sequence obtained from the remains of a 5,200 year-old horse from Yakutia appears within the diversity of a now-extinct population of wild horses that the team discovered last year in Late Pleistocene fossils from the Taymir peninsula, Central Siberia. This new finding extends by thousands of kilometers eastwards the geographical range of this divergent horse population, which became separated from the lineage leading to modern horses some 150,000 years ago. It also extends its temporal range up to 5,200 years ago, a time when woolly mammoths also became extinct. Dr. Ludovic Orlando says:

- This population did not appear on any radar until we sequenced the genomes of some of its members. With 150,000 years of divergence with the lineage leading to modern horses, this makes the roots of this population as deep as the origins of our human species.

The full press release: Adapting to -70 degrees in Siberia: a tale of Yakutian horses

Credit Science Daily

REFERENCES

Librado et al (2015) Tracking the origins of Yakutian horses and the genetic basis for their fast adaptation to subarctic environments. Proceedings of the National Academy of Sciences, 2015; 201513696 DOI: 10.1073/pnas.1513696112

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