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Evolution of complex structures

Discussion of everything related to the Theory of Evolution.

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Evolution of complex structures

Postby Niclas » Fri Jun 22, 2012 3:53 pm

Hello guys, I recently had a year of evolution in high school and a question came to my mind - don't worry, I'm not a creationist and I don't want to debunk Darwin as Evolution is an observable effect.

But the following thing got me curious:

Evolution happens because of mutations and recombination. Which suggests that only mutations on the DNA can create complete new things instead of just combining the things that exist.

So... we have many kind of complex structures which were not so complex when they developed, but:

As these things started to develop once, they weren't so complex at all at the beginning because there were needed more mutations and selection to optimize them.

How can e.g. the evolutionary beginning of an arm, a heart or wings kind of survive the process of evolution as their first forms weren't just mostly useless ( due to them not being complex and not having a function yet) and they were just like... extra mass?


Maybe I understood something wrong but I guess you'll tell me the truth ;)
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Postby Darby » Mon Jun 25, 2012 1:17 am

Something simple can't have a function?
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Postby canalon » Mon Jun 25, 2012 2:29 am

See examples:
The eye: http://www.youtube.com/watch?v=2ybWucMx4W8
The wings: http://www.youtube.com/watch?v=ca6dl_12KUc
Furthermore some structure can appear fully formed because of the way limb formation are controlled. There are quite a lot of version of mutant drosophila that have bits where they should not after their HOX genes have mutated (antennapedia [http://en.wikipedia.org/wiki/Antennapedia]being just one the most famous)
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Postby david23 » Sat Jul 14, 2012 9:47 pm

why are these op posts all so convoluted and just hard to read. Come on dont try to use complex words just say what you want to say. I mean do non-COMPLEX things die and cant survive? sure they do and thats how selection works.
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Re: Evolution of complex structures

Postby Forests » Thu Jul 19, 2012 6:14 pm

I don't know why but most internet forums when it comes to evolutionary mechanisms most folk are stuck in the 1950s by citing only mutation and selection. Mutation and selection are not the only evolutionary mechanisms.

Evolution happens because of mutations and recombination.


Evolution is much more complex than that. You want to know how complex structures have come about? Then educate yourself about all of the known evolutionary mechanisms not just mutation.

See:

Genetic drift, gene flow, horizontal gene transfer, molecular drive, saltation, symbiosis, niche construction, evo-devo, epigenetics (also see neo-Lamarckism) hybridization, self-organization etc... theres even a mechanism called "internal selection" theres also controversial stuff like orthogenesis or directed mutagenesis or even claims about evolution & earths magnetic field or electromagnetic fields or if you want to be even more heretical check out rupert sheldrake's ideas about morphogenetic fields or research into "biofields"... Theres loads of evolutionary mechanisms and processes out there to study. When we think about how complex nature is and how many of these mechanisms there are then its not suprising that we have complex structures as there is many evolutionary mechanisms at work. There is no need to resort to creationism.

Which suggests that only mutations on the DNA can create complete new things instead of just combining the things that exist.


Most mutations are neutral, there are beneficial mutations which have been observed, but there is also evidence for many other evolutionary mechanisms see some of the above for just a small amount of them... theres many others.
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