Comments on: Science is Sexy: What is Evolution?

By: Free Movies

Free Movies — Tue, 13 Sep 2011 18:13:14 +0000

Difficulty This is progress, almost all mutations occur at the molecular level is inadequate. Describe the changes that are not really changing, but "natural selection" takes place under very different status.

By: killer_sloth

killer_sloth — Wed, 30 Mar 2011 02:11:00 +0000

Charles Darwin was actually not the "founder" of evolution. He was the founder of the idea of natural selection, which is the mechanism by which evolution occurs.

By: robrob

robrob — Thu, 19 Aug 2010 19:53:00 +0000

That first part is true: most mutations are maladaptive. However, the useful changes don't really happen under different circumstances. There are many types of mutations, like specific point mutations (changes in a single amino acid), to larger changes where entire sections of a chromosome are moved or exchanged. Some changes add information (a changing or new DNA codon), some take away information (deletion of a gene or reduction in it's expression) and some simply change what is already there (moving genes), but regardless these are all forms of CHANGE in an organism (and it's offspring, it is has any). True, most semi-random change is bad (I say semi because nothing is truly random – the laws of physics and chemistry and biology play a huge role in mutations and other changes), but these bad changes are weeded out very quickly. Which leaves only the neutral or useful changes. Granted, these neutral or positive changes may not be vey common… but when thousands or millions of individuals in a species exists for hundreds, thousands, or even more years, these "uncommon" changes are not really that rare, and the positive effects they might have are quickly amplified by natural selection.

By: Anonymous

Anonymous — Sat, 04 Jul 2009 01:34:00 +0000

Evolution – well explained.

By: उन्मुक्त

उन्मुक्त — Sat, 04 Jul 2009 01:34:00 +0000

Evolution – well explained.

By: SoonerSteve

SoonerSteve — Wed, 20 May 2009 18:07:00 +0000

The problem with evolution is this, virtually every mutation that occurs on a molecular level is maladaptive. The changes that are described(not really evolution but 'natural selection') occur under very different circumstances.

By: SoonerSteve

SoonerSteve — Wed, 20 May 2009 18:07:00 +0000

The problem with evolution is this, virtually every mutation that occurs on a molecular level is maladaptive. The changes that are described(not really evolution but ‘natural selection’) occur under very different circumstances.

By: Scott-O

Scott-O — Wed, 20 May 2009 17:36:00 +0000

George Mason! Who hooooooo! Best school I ever flunked out of!

Thanks for a great article that really simplifies the whole messy thing.

By: Scott-O

Scott-O — Wed, 20 May 2009 17:36:00 +0000

George Mason! Who hooooooo! Best school I ever flunked out of!
Thanks for a great article that really simplifies the whole messy thing.

By: Chad

Chad — Wed, 20 May 2009 13:30:00 +0000

Great read! Thanks for posting.

By: Chad

Chad — Wed, 20 May 2009 13:30:00 +0000

Great read! Thanks for posting.

By: Jimmy Rogers

Jimmy Rogers — Tue, 19 May 2009 17:41:00 +0000

A very good point Mark!

This process is actually the way in which recombinant bacterial strains are created. Microbiologists introduce a gene segment that is only taken up by a fraction of the millions of bacteria in a culture. The gene segment includes a gene for resistance to an antibiotic and the desired target gene (like creating insulin). The antibiotic is introduced to the culture and all but the small group with the recombinant DNA are destroyed. This is of course artificial selection, but the effect is the same.