16 September 2011

New limbs from old fins, part 2

Titktaalik roseae.
Image from
https://tiktaalik.uchicago.edu/index.html
The second post in my series on limb evolution is now up at the BioLogos site. This installment reviews the fossil evidence on fin-to-limb evolution, introducing the famous Tiktaalik. Next up: evidence from developmental biology.
The first post at BioLogos outlined limb structure and some historical background. The series at BioLogos was spawned by an idea here at QoD, which aimed to discuss some new findings in the fins-to-limbs story. Those new findings will be discussed in the final installment of the series at BioLogos.

*Edit July 2020: The series was consolidated into a single article on the BioLogos site. The link now goes to that single article.


3 comments:

Berend de Boer said...

Steve: But the hunt for the earliest tetrapods was an effort to test a hypothesis that had generated a prediction.
Finding evidence that supports your hypothesis isn't what science is about. You must have read/know Karl Popper...

This is just working within the paradigm (Thomas Kuhn).

So what do they do? They hunt in "375 million" year rocks (yes, it's that easy, all rocks come with a time stamp). Voila, true scientists at work!

Unfortunately at the end Steve has to admit, nope, their find had NOTHING to do with their hypothesis as we now date the Tiktaalik at 400 million years ago. So they didn't confirm their hypothesis AT ALL!!!

I judge student science projects, and they would miss some sorely needed marks for reasoning like this.

The only constant in the fossil record is that it doesn't exist (we can pretty much guarantee that every find is wrong, overhyped, and misplaced), and that fossils get pushed further and further back in time.

SteveMatheson said...

Berend, you clearly believe the vast majority of scientists to be careless buffoons. Since that includes me, I conclude that you would consider it a waste of time to discuss these issues any further with me. You are welcome to continue posting your dismissive comments here, but please don't expect any response from me.

Berend de Boer said...

I leave the "careless buffoons" remark, nothing in my post said anything about scientists in general.

I addressed your logic. What happened is they worked within a framework, found something that appeared to confirm their hypothesis, and a later find completely upset the story. Their hypothesis was falsified. That's the big story.

Clark on the redating: "Other paleontologists are taken aback by the discovery of the tracks. "We thought we'd pinned down the origin of limbed tetrapods," says Jennifer Clack of the University of Cambridge in the United Kingdom. "We have to rethink the whole thing."

http://news.sciencemag.org/sciencenow/2010/01/06-02.html

And you basically ignore that in your article.

Pardon me for being dismissive about such logic. And no, I don't think you are a careless buffoon.