Freethought & Rationalism Archive

The_Unknown_Banana · 08-10-2003, 11:32 PM

I'm still in the debate with my friend

Anyway, on giving her examples on the evolution of the horse, I showed her the pictures from these links:

http://www.flmnh.ufl.edu/natsci/vert...hc/hyraco1.htm
http://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/oroh.htm
http://www.flmnh.ufl.edu/natsci/vert...fhc/mesoh1.htm

Her response is that they all could be anything (ie. Hyracotherium could be part hippo, Orohippus could be a cow etc. These were her examples). A valid point, I guess.

So my question is, how exactly do scientists decide which species is actually part of the line of evolutionary progress of a modern creature just from the fossils? There must be a little more to it than just the looks... are skeletal remains that distinctive? (How should I respond to such an accusation?)

Thanks in advance for any replies

The_Unknown_Banana · 08-11-2003, 02:18 AM

Eh, I couldn't find anything on the methods used to determine what group fossils belong to, but I replied with the following using http://www.talkorigins.org/faqs/hors...vol.html#part2 anyway:

Quote:

Alright, I understand your point. But answer me this - where did modern day horses come from, and why aren't there any fossils remaining of them in the past? How else can you explain the sequence of horse fossils? Even if creationists insist on ignoring the transitional fossils, again, how can the unmistakable sequence of these fossils be explained? Did God create Hyracotherium, then kill off Hyracotherium and create some Hyracotherium-Orohippus intermediates, then kill off the intermediates and create Orohippus, then kill off Orohippus and create Epihippus, then allow Epihippus to "microevolve" into Duchesnehippus, then kill off Duchesnehippus and create Mesohippus, then create some Mesohippus-Miohippus intermediates, then create Miohippus, then kill off Mesohippus, etc.....each species coincidentally similar to the species that came just before and came just after?
Creationism fails to explain the sequence of known horse fossils from the last 50 million years. That is, without invoking the "God Created Everything To Look Just Like Evolution Happened" Theory.

(And I'm not even mentioning all the other evidence for evolution that is totally independent of the fossil record -- developmental biology, comparative DNA & protein studies, morphological analyses, biogeography, etc. The fossil record, horses included, is only a small part of the story)

Any input on methods used would still be appreciated though

Ergaster · 08-12-2003, 03:58 PM

The simple answer: detailed comparative anatomy. Essentially, identifying diagnostic bits of anatomy that are known only for the lineage in question. Very often this includes detailed anatomy of the dentition, such as the size, shape, number, and placement of molar cusps. The basic plan remains the same even if extreme modifications and adaptations occur. Paleontologists tend to become expert comparative anatomists. For example, Hyracotherium couldn't be a "hippo" because it does not have the diagnostic features of hippos. Nor would it have the diagnostic freatures of artiodactyls, which hippos are and Hyracotherium is not (it is a perissodactyl). Interestingly, turns out fossil whales have a very diagnostic bit of artiodactyl anatomy: the distinctive ankle bones Unique to artiodactyls (yeah, they were whales with legs, and they can tell they were whales because whales have a very unique and distinct ear anatomy).

Quote:

Originally posted by The_Unknown_Banana
I'm still in the debate with my friend

Anyway, on giving her examples on the evolution of the horse, I showed her the pictures from these links:

http://www.flmnh.ufl.edu/natsci/vert...hc/hyraco1.htm
http://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/oroh.htm
http://www.flmnh.ufl.edu/natsci/vert...fhc/mesoh1.htm

Her response is that they all could be anything (ie. Hyracotherium could be part hippo, Orohippus could be a cow etc. These were her examples). A valid point, I guess.

So my question is, how exactly do scientists decide which species is actually part of the line of evolutionary progress of a modern creature just from the fossils? There must be a little more to it than just the looks... are skeletal remains that distinctive? (How should I respond to such an accusation?)

Thanks in advance for any replies

Dr.GH · 08-12-2003, 05:19 PM

Let me suggest that you read the following:

http://www.aaas.org/spp/dser/evoluti...ory/mayr.shtml

The_Unknown_Banana · 08-14-2003, 09:31 PM

Thanks, that helps a lot!

08-10-2003, 11:32 PM	#1
The_Unknown_Banana Regular Member Join Date: May 2003 Location: New Zealand Posts: 179	How do the experts determine fossil characteristics? I'm still in the debate with my friend Anyway, on giving her examples on the evolution of the horse, I showed her the pictures from these links: http://www.flmnh.ufl.edu/natsci/vert...hc/hyraco1.htm http://www.flmnh.ufl.edu/natsci/vertpaleo/fhc/oroh.htm http://www.flmnh.ufl.edu/natsci/vert...fhc/mesoh1.htm Her response is that they all could be anything (ie. Hyracotherium could be part hippo, Orohippus could be a cow etc. These were her examples). A valid point, I guess. So my question is, how exactly do scientists decide which species is actually part of the line of evolutionary progress of a modern creature just from the fossils? There must be a little more to it than just the looks... are skeletal remains that distinctive? (How should I respond to such an accusation?) Thanks in advance for any replies

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08-12-2003, 05:19 PM	#4
Dr.GH Veteran Member Join Date: Jul 2001 Location: Dana Point, Ca, USA Posts: 2,115	Let me suggest that you read the following: http://www.aaas.org/spp/dser/evoluti...ory/mayr.shtml

08-14-2003, 09:31 PM	#5
The_Unknown_Banana Regular Member Join Date: May 2003 Location: New Zealand Posts: 179	Thanks, that helps a lot!

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