Tuesday, January 10, 2017

De-Domesticating The Cow

Ten thousands years ago, people in the Fertile Crescent domesticated the wild auroch and the result was the domesticated cow (taurine cattle in the Fertile Crescent) and within a couple of thousand years, zebu cattle were also domesticated from wild auroch's in India. Based upon the mtDNA on domesticated taurine cattle, it appears that all domesticated taurine cattle originated from about 80 wild female aurochs in the Near East.

About 7,200 years ago, domesticated cows reached Europe's Pontic-Caspian steppe, and people who had used to hunt wild aurochs, wild horses (three different species), and wild pigs, turned to domesticated cows, sheep and pigs.

The wild auroch species that give rise to domesticated cows went extinct when the last members of the last remaining herd of their kind died in Poland in 1627.

Now, in an enterprise that is part old school selective breeding and part ecological experiment, Europeans are trying to de-domesticate the cow (a process also called "re-wilding") and return a wild auroch-like species in their forests. The process mirrors efforts to restore bison herds and wolf packs to the American West.
Conservationists now believe the loss of the keystone herbivore was tragic for biodiversity in Europe, arguing that the aurochs' huge appetite for grazing provided a natural "gardening service" that maintained landscapes and created the conditions for other species to thrive. . . . 
Ecologist Ronald Goderie launched the Tauros programme in 2008, seeking to address failing ecosystems. The most powerful herbivore in European history seemed to offer a solution. 
"We thought we needed a grazer that is fully self-sufficient in case of big predators...and could do the job of grazing big wild areas," says Goderie. "We reasoned that this animal would have to resemble an auroch." 
Rather than attempt the type of gene editing or high-tech de-extinction approaches being employed for species from woolly mammoths to passenger pigeons, Goderie chose a method known as back-breeding to create a substitute bovine he named "Tauros." 
Auroch genes remain present in various breeds of cattle around the continent, and the team identified descendants in Spain, Portugal, Italy and the Balkans. Geneticists advised breeding certain species together to produce offspring closer to the qualities of an auroch, and then breed the offspring. 
The animals get closer with each generation, and the team have the advantage of being able to test the offspring's DNA against the complete genome of an auroch, which was successfully sequenced at University College Dublin. 
"You could see from the first generation that apart from the horn size, there was enough wild in the breed to produce animals far closer to the auroch than we would have expected," says Goderie. 
The ecologist had predicted that seven generations would be necessary for the desired outcome, which might be achieved by 2025. The program is now in its fourth generation, and pilot schemes across Europe are offering encouragement. 
The Tauros programme connected with Rewilding Europe early on, a group that supports the restoration of natural processes through projects that range from rebuilding rivers to introducing apex predators. . . . "We see progress not only in looks and behavior but also in de-domestication of the animals," he says. "This is a challenging process as they have to adapt to the presence of large packs of wolves." 
Herds of herbivores are habitually decimated by local wolves at the Croatian site, says Goderie. By contrast, the Tauros learned to defend themselves and suffered few losses. 
. . . . 
"Bovines can shape habitats and facilitate other species because of their behavior, and the more primitive and close to the wild the better because it means that eventually they can become part of the natural system." 
Many European landscapes are in dire need of grazing animals, which can otherwise become uninhabitable for other species. 
"Without grazing everything becomes forest, or barren land when there is agriculture," says [Frans] Schepers [managing director of Rewilding Europe]. "The gradients in between are so important for biodiversity, from open soil to grassland and 'mosaic landscapes. The Rhodope Mountains of Bulgaria are among the richest areas for reptiles such as tortoises, snakes and lizards. But they need open spaces or they lose their habitat." . . .
"Questions abound whether primarily wetland forests like the aurochs used to inhabit still exist, whether it could negatively impact wild or domestic plants or animals, and if it might endanger people." 
The successful introduction of bison in the US shows that such initiatives can have a positive impact, says Dr. Eric Dinerstein of conservation group Resolve, but he adds that one intervention can lead to another. 
"If an ecosystem evolved with large herbivores. . . there is not an alternative and you need something in its functional role," he says. "But to introduce aurochs, you may need predators as well."
Perhaps, humans, one of the main predators of aurochs in the Mesolithic era, will return to that role.

Rewilding is one area where North America has an edge over Europe. It has more open spaces, and is much less far removed in time from an era in which humans had a much milder impact on wild species.

Restoring the bison meant rolling back the clock a century, while the restoration of aurochs depends upon gleaning genes from them that entered domesticated cattle many thousands of years ago and restoring habitats that have likewise changed far more dramatically.

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