Several missing links between ancient fish and tiktaalik?

allah888

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Aug 15, 2014
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I'll assume the majority of you know about tiktaalik; so this is my concern: I believe in evolution, but where are all the missing links between fish and tiktaalik? It's simple, a fish doesn't have a neck and has the eyes on the side; tiktaalik has a flat head with eyes on top. We should be finding fossils of the whole process, like the head slowly flattening over different species to finally form tiktaalik. Do I make sense with this?
 

Oddball

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Trying to gain a full evolutionary answer from a monospecific species isn't an easy task. Also, making a bold statement that fish had eyes on the sides of their head is a misdirection since there are (and were) numerous species with eyes on top of their head. As well as species with dorso-ventrally compressed cranial structures. As far as having a neck, there are species of fish that have developed adaptations in their musculoskeletal archetecture to allow them to make movements that other species cannot. Polypterids are a quick example of a species adapting a left and right head movement.

The question itself is written too broadly to know where to begin such a discussion. Many other evolutionary links were being created at the same time in numerous different niches and involving countless other species. Add to that the likelihood that tiktaalik may be in the company of thousands of other species that proved unsuccessful in their adaptations giving them an advantage over another developing genus and, therefore, their line ended. Much like the lines that developed the Rutiodons.
 

Aquanero

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This is a pretty good explanation: http://en.wikipedia.org/wiki/Tiktaalik. I think if you follow the evolutionary path backwards you can see how they evolved form fish and then into true amphibians.
 

Ponera

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I'm a paleontologist. Basically the problem with your question is that polys are actually actinopterygians and not sarcops. They are basal actinops. Basically for sarcops you're looking at something like eusthenopteron or the so called rhipidistians (polyphyletic class containing lots of tetrapod relatives.)

Another issue is that there are issues with the fossil record. Not that it is wrong, that it is incomplete. Many of these animals lived in poor despositional environments so it isnt like horses or whales where we have a virtually flawleas record. Your best bet would honestly be to look up sarcopterygian or tetrapod ancestors to get a pretty okay view on things.

Bichirs are on the outside of the sarcops but are basal actinops meaning they are close to that split but even further from sarcop/tetrapod split. Not that far though. So there isn't a missing link between them, just a common ancestor way back between titaalik and bichirs. Google sarcoptygian and actinopterygian to understand this divergence better.

Sorry I can't be more helpful I'm actually on my damn phone cause I'm in the field right now.
 
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