imported_Kat Posted October 30, 2003 Posted October 30, 2003 At the moment I'm doing my literature review for my thesis on the evolution of canine social behaviour. Now I know we had a dewclaw debate a little while ago, so here is some fascinating scientific evidence to confirm that dogs do not need dew claws. Sit back and relax for a history lesson! 60 million years ago arboreal animals called Miacids roamed the earth. From miacids diverged the line of Cynodictis which eventually evolved to a line including Tomarctus species which resembled a long legged wolf with the body of a weasel. Now, Miacids were tree-dwelling (arboreal) and had 5 toes on both fore and hind feet. As they diverged to eventually become Tomarctus, arboreal behaviour evolved to terrestrial (this was due to the need to exploit a much wider environment for food and survival and also because dinosaurs began to die out so predation was decreased). As they evolved to become terrestrial animals, fossil records show that the 5th toe (dew claw) was significantly reduced in size, and eventually became vestigial (of no use as they were no longer needed due to the behaviour and habitat change). The paw pad also reduced in size. Dogs today have dewclaws just like wolves but these dwclaws are unecessary, unless any of you have dogs that climb trees! Natural selection isn't allowed to take place due to humans interfering continually and breeding, but if it were, then dogs today wouldn't even have dewclaws. Why have something you don't need? Hope this proves to be fascinating for the rest of you as it was for me :wink: Quote
Guest Anonymous Posted October 31, 2003 Posted October 31, 2003 [quote name='Kat']As they evolved to become terrestrial animals, fossil records show that the 5th toe (dew claw) was significantly reduced in size, and eventually became vestigial (of no use as they were no longer needed due to the behaviour and habitat change). The paw pad also reduced in size. Dogs today have dewclaws just like wolves but these dwclaws are unecessary, unless any of you have dogs that climb trees! Natural selection isn't allowed to take place due to humans interfering continually and breeding, but if it were, then dogs today wouldn't even have dewclaws. Why have something you don't need? [/quote] hmm, somewhere there seems to be a gap in that explanation tho. if it were that simple, why do wolves and other wild canids still have dewclaws? i'd say they have as much (or as little) use of them as domestic dogs do and humans haven't interfered in their evolution. Quote
Rowie-the-Pooh Posted October 31, 2003 Posted October 31, 2003 [quote name='Anonymous'][quote name='Kat']As they evolved to become terrestrial animals, fossil records show that the 5th toe (dew claw) was significantly reduced in size, and eventually became vestigial (of no use as they were no longer needed due to the behaviour and habitat change). The paw pad also reduced in size. Dogs today have dewclaws just like wolves but these dwclaws are unecessary, unless any of you have dogs that climb trees! Natural selection isn't allowed to take place due to humans interfering continually and breeding, but if it were, then dogs today wouldn't even have dewclaws. Why have something you don't need? [/quote] hmm, somewhere there seems to be a gap in that explanation tho. if it were that simple, why do wolves and other wild canids still have dewclaws? i'd say they have as much (or as little) use of them as domestic dogs do and humans haven't interfered in their evolution. [/quote] Good point, Guest! :) Thanks for the post, Kat! :) Quote
imported_Kat Posted October 31, 2003 Author Posted October 31, 2003 Well in response to your question the wolves were the first canids after Tomarctus so to speak. From extinct wolf species, other animals like jackals and Coyotes evolved. Foxes evolved on a different linage. Wolves started to undergo domestication shortly after diverging from Tomarctus, so unfortunately we can't go back millions of years and find out the real truth, but the picture has been put together from fossil records. It would appear that domestication and a form of artificial selection whereby wolves were kept as companions, was responsible for the interference in the dewclaw evolution. Food for thought! :wink: Quote
Guest Anonymous Posted October 31, 2003 Posted October 31, 2003 not all wolves (or other canids) were domesticated or bred to domesticated ones though, so i still think it can't be the whole story. just think how many people lived on this planet some thousand years ago, and how many animals. if that theory were without gaps, no wolves today would have dewclaws. i do not believe that the relatively small ratio of domesticated animals would have been able to influence a gigantic wild population to that extent. Quote
Guest Anonymous Posted November 2, 2003 Posted November 2, 2003 Hmmm... I don't know if I'd believe the bit about dogs not even having dew claws today if it weren't for selective breeding... but I fully understand about the dew claw remaining from what was once a functional claw, and not being of any use today. Just because it is there doesn't mean it is there for a reason. Quote
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