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Author Topic:   Transitional fossils not proof of evolution?
Dr Adequate
Member (Idle past 396 days)
Posts: 16113
Joined: 07-20-2006


Message 190 of 223 (333772)
07-20-2006 3:46 PM


for me a "transitional fossil" is a fossil that's part say fish and part frog.
How much fish and how much frog? Along that line of development we have such varying delights as Achoania, Osteolepis, Styloichthys, Eusthenopteron, Panderichthys, Crassigyrinus, Tiktaalik, Ichthyostega, Acanthostega, and Triadobachtratus. Take your pick.
Edited by Dr Adequate, : To make it prettier.

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Dr Adequate
Member (Idle past 396 days)
Posts: 16113
Joined: 07-20-2006


Message 208 of 223 (341323)
08-19-2006 8:48 AM
Reply to: Message 203 by Chiroptera
08-18-2006 9:54 PM


No, i think you don't understand what i'm saying. We have lots of fossils of horseshoe crabs, and we have live ones that match the fossils. Now sure, there could be changes in the DNA, but humans look different than their supposed ancestors. (according to the theory of evolution) Now, the time between humans and their ancestors is much shorter than the time between the million year old horseshoe crab, and the ones alive today.
Evolution doesn't happen just 'cos time passes (well, apart from boring old neutral drift). Adaptive evolution happens because there's a selective pressure acting on the variation in the gene pool. If you think that some lineage of horseshoe crabs should have evolved into something else --- then what? And how? Into what vacant niche?
By contrast, in the case of humans the origin of grasslands opened up a niche in which adaptation for bipedalism was advantageous ('cos in open country it allows you to see further: it is interesting to note that even monkeys will adopt a bipedal posture when they come down from the trees into open spaces.) There is your vacant niche: it was certain that some animals would adapt to living on the savanahs. See for example Bobe andBehrensmeyer, "The expansion of grassland ecosystems in Africa in relation to mammalial evolution and the origin of the genus Homo", Palaeogeography, Palaeoclimatology, Palaeoecology 207: 399-420. (2004).
Our lineage faced a new environment, a new challenge, and a new set of selective pressures when Africa dried and the jungles shrank. Horseshoe crabs did not.

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Dr Adequate
Member (Idle past 396 days)
Posts: 16113
Joined: 07-20-2006


Message 214 of 223 (341596)
08-19-2006 11:03 PM
Reply to: Message 212 by Chuteleach
08-19-2006 10:09 PM


I notice that on that page they identify the modern organisms by species but the fossil specimens only by genus. Deliberate deceit, or did their poor little brains get muddled? You decide. In any case, they do not assert that they are the same species.
'Cos they can't.
And they do not give the slightest reason why they think a conservative lineage is evidence against evolution. Not one line of argument, not one shred of reasoning.
'Cos they can't.

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