Its all about selection for flight distance. (Oh, for plants, that's dispersal distance!)
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One of the toughest concepts to grasp about evolution is its lack of direction. Take the classic image of the evolution of man, from knuckle-walking ape to strong, smart hunter:
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Hello everyone! Happy Carnival!
evâoâluâtionâ [ev-uh-loo-shuhn or, especially Brit., ee-vuh-]ânoun1. A gradual process in which something changes into a different and usually more complex or better form. Most of the time, when we think 'evolution', we think about animals and genetic…
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I made a presentation about Belyaev's experiment when I was at school :)
It turns out, that a lot of other changes also took place. For example, size and mass of brain reduced (almost by 20%). Some instincts were lost. And so on.
I still have this presentation, but it's in Russian :)
As soon as I saw this I thought about the transition of wolves to dogs. Of course people bred the more friendly wolves, it makes sense.
Amazing stuff. I wonder too about our feline friends. They've been bred for tame behavior, or more kittenish behavior. Yet I have a red mackerel tabby named Angie sitting right next to me. Oh she's a feisty cat, if she doesn't like something she lets you know.
Great video, having read about these experiments it was great to get a visual.
Of course, this means that the wild fox populations from which the foxes were brought into captivity must have had substantial genetic variation in the genes controlling aggressiveness etc. This in turn probably means that features of their natural environment (physical, social) sometimes favoured the 'domestication' phenotype.
The felines are just waiting for their chance. It will come some day.
Rosie: One can imagine that a fox/wolf that was too 'domesticated' ... because it had the odd combination of traits randomly from among the variation you (correctly) suggest as likely, would be selected against in the wild (but not on the fox farm or by the Cave Kids who insist on keeping the puppy-wolf).
This short movie was far too simple. Susan Crockford has a theory (about thyroid hormones under stress) as an agent of faster evolution.
see: http://www.coconutstudio.com/Iodine%20Human%20Catalyst.htm#Heterochrony
quote:
D.K. Belyaev and his colleagues selected, from local fur farms, about 20% that were less fearful and aggressive, but still could not be handled. After a few generations, some females were in oestrus twice a year instead of just once (although it took time for the males to catch up).
Suddenly, after just twenty generations, novel traits suddenly appeared: curled tails, floppy ears, brown piebald, and classic white piebald coat colourings.
Inexplicably, all of these traits, once they had appeared, inherited in dominant fashion. Their offspring normally had the same traits
It's not limited to selection, but selection for underlying, possibly unknown traits.
regards
Richard
When domesticated dogs are turned loose in the wilds, they quickly revert to wildness, losing their dog-looks and dog-habits, quickly turning wolf-like. It doesn't take long, either.
I was once with some friends hunting in the Mojave Desert when a pack of feral dogs began hunting us. They kept a circle around us, each of them probing for weaknesses, making the best use of terrain. Despite the fact that we were heavily armed, I was never more afraid in my life. The obvious intelligence and cunning of those animals reminded me so much of wild beasts I came to know through David Attenborough.
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