How did dog breeds changed their appearance so much in such a short time of evolution?
how did dog breeds changed their appearance so much in such a short time of evolution ? I mean there are very significant differences between dog breeds e.g. chiwawa vs great dane. It sais that people selected and breed them in the last thousands of years. A few thousands of years seems a very short period to me for such big differences.
That is the power of artificial selection. Breeders selected for the traits that were desired and only those dogs reproduced. Look at the Siberian Fox experiment. All it took was 10 generations for domesticated foxes to emerge. Imagine how much more changes could be selected for over centuries.
The miniature breeds share a mutation near a gene for a growth factor receptor. A common mutation may result in a common trait.
That is the power of artificial selection. Breeders selected for the traits that were desired and only those dogs reproduced. Look at the Siberian Fox experiment. All it took was 10 generations for domesticated foxes to emerge. Imagine how much more changes could be selected for over centuries.
The miniature breeds share a mutation near a gene for a growth factor receptor. A common mutation may result in a common trait.
References :
http://en.wikipedia.org/wiki/Domesticated_silver_fox
http://www.nature.com/scitable/content/leader-of-the-pack-gene-mapping-in-700103
Strong natural or artificial selection leading to marked adaption.
But note that all remain dogs. Adaption can result in separate species; i.e. they can’t interbreed; but the animals do not change from one kind to another. Dogs remain dogs. Bacteria do not evolve into humans.
The current state of many of the dog breeds shows what happens when selection is taken too far. These dogs, far from being more perfect, ‘evolved’, animals, were described as “a parade of mutants” by one critic … Because they are over-specialized, they are more prone to disease and shorter-lived than their ‘mongrel’ relatives. It is clear that both artificial and natural selection work by decreasing the amount of genetic information in a population, which is the exact opposite of what evolution would require [1]
References :
[1] http://creation.com/mutant-parade-purebred-dogs