Well, not “evolution,” even though it must be marketed that way.
For many thousands of years, humans have bred dogs, goats, chickens and other animals to make them suitable for use as domestic animals, in a process known as domestication. Humans have selected the individuals that possess desirable traits and bred them with similar individuals, such that the offspring possess the same traits. The genetic material of the animal has partially changed during the development of the species from its wild form to a domesticated one. The opposite process also takes place, when domesticated animals readapt to life in the wild, in a process known as feralization. By investigating what happens in an animal’s genetic material, we can study whether the effects of domestication by humans are long-term or short-term. Can evolution go backwards?
“We wanted to see whether feralization is the same process as domestication, but in the other direction. Our results show that this is not the case. It is largely separate genes that are affected when domesticated chickens return to the wild,” says Dominic Wright.
Life in freedom brings with it greater threats from predators and disease, but it means that a chicken can choose freely who to mate with. Traits that make an individual attractive, such as an impressive comb, play a role in the selection of partners.
“Sexual selection is important in wild animals, and so it’s logical that genes that control comb size and similar traits are affected when an animal returns to the wild. Paper. (public access) – M. Johnsson, E. Gering, P. Willis, S. Lopez, L. Van Dorp, G. Hellenthal, R. Henriksen, U. Friberg, D. Wright. Feralisation targets different genomic loci to domestication in the chicken. Nature Communications, 2016; 7: 12950 DOI: 10.1038/ncomms12950 More.
That’s where the rubbish creeps in. Female animals in the wild usually have little choice of what male animal they mate with. The males see to that. But never mind, we learned something: Different genes are active during feralization. Too bad so much Darwin rubbish gets mixed in.
It’s noteworthy that the authors avoid any question as to whether extreme human variations in the animal create a new “species.”
See also: Can sex explain evolution?
Speciation: Red wold not endangered? A hybrid
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