by ChrisDG on December 13th, 2006
Natural selection is the idea that the creatures more suited to an environment will live long enough to reproduce and pass on their genes. So in an example, birds with genes that code for long thin beaks may live longer because the size of their beaks allows them to probe into small spaces for insects, allowing them to feed easily, and so live longer. They can reproduce and their genes that code for a longer beak are passed on. The ones with shorter beaks have less chance of competing for food because they cannot reach hard to reach places so have less food available so die out more. Other creatures may flourish with more strength, or better eyesight etc.
Similarly, bacteria with genes that enable them to withstand e.g. heat allow these bacteria to set up colonies in hot springs, where other bacteria would die out.
Natural selection does not cause genetic information, as reproduction (in whatever way - sexual, binary fission etc) produces genetic information. So basically natural selection is the result of genetic information. Genetic mutations arise in the wild that may or may not give creatures an advantage over others of the same species and so coupled with exchange of genetic material e.g. during sex, leads to constantly genetically new creatures being born.
by Aladdin9494 on May 15th, 2009
i'd say natural selection is a result of genes, picking out the weaker genes, and letting stronger genes survive.
Aside from a few US states, where else is teaching evolution deemed controversial?
by Mastodon on November 24th, 2009
| 4 people like this
Is evolution just a theory or fact?
by plumvalley on January 3rd, 2010
| 1 person likes this
Does Islam teach Evolution
ie Darwinism
by The Seeker on November 22nd, 2009
| 2 people like this
Do you think evolution should be taught in public schools?
by Now Grateful on November 22nd, 2009
| 9 people like this
Why are there not millions/billions of fossils showing the failed animals of the evolutionary theory of natural selection?
by plumvalley on December 27th, 2009
| 1 person likes this
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Comments
Maybe I'm wrong, but if sex is necessary for genetic information sexual organisms could not have evolved from asexual organisms. Also, any organism that lives long enough to reproduce already has genetic information by definition, so positing sex as an explanation is circular and does not explain the source of genetic info.
by IdeaSniper on December 14th, 2006
I did not say sex, I said reproduction in whatever way, including sex. Read the answer correctly.
by ChrisDG on December 14th, 2006
In response to your second point, obviously an organism that can reproduce has genetic information. Where did it come from? The reproductive process of its parent(s). The whole process of reproduction is in a way circular. What you are asking is how did chemical compounds first become genetic information. In essence you are asking how did life begin. That is an entirely different question. My answer holds.
by ChrisDG on December 14th, 2006
Since parents need genetic info before they can pass it to their offspring and even the ability to have offspring requires genetic info reproduction misdirects us from the fact that the only things that could possibly generate genetic info are errors in the genetic code called mutations.
by IdeaSniper on December 14th, 2006
Actually no. Though mutations obviously do happen you are forgetting that genetic infomrtaion can also be added, for example by retroviruses and the like. A massively important example of this is the evolution of eukaryotes cells to produce mitochondria in their cells. Mitochondria actually possess their own DNA in addition to that found in the nucleus. This DNA can be traced back to less complex prokaryotic organisms, and so it is strongly believed (though admittedly I don't know if it can be proven) that at some point, the prokaryotic part was incorporated into eukaryotic cells and allowed them to produce energy in new ways. This allowed the cells to become ever more complex and eventually evolve into the large multi-celllular creatures we find ourselves and others as. This is obviously a far more drastic way of changing genetics than mere mutations.
by ChrisDG on December 14th, 2006