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Darwin came up with a theory of a _mechanism_ (natural selection) by which the evolution that was _observed_ in nature happens. Neither Darwin nor Wallace "disc
by skywhopper 10y ago
Darwin came up with a theory of a _mechanism_ (natural selection) by which the evolution that was _observed_ in nature happens. Neither Darwin nor Wallace "discovered" evolution. Evolution is a feature of our world, easily observed and utilized by animal and plant breeders for hundreds of centuries.
But what was brilliant about Darwin's theory was that he proposed it while knowing basically nothing about the underlying biological features that enabled it--ie, discrete genes that are duplicated, sometimes with errors, in successive generations of individuals.
What blew my mind when I first understood these ideas was that given discrete genes, and given unequal chances of successful reproduction for various sets of genes, natural selection is essentially axiomatic. The rules of the game force natural selection to exist. There is no other way it can work. So I think it's fair to say that Darwin discovered natural selection. But not evolution.
By the way if you are interested in this topic at all and you haven't read "On the Origin of Species", do yourself a favor and seek it out. It's public domain so it's available all over the Internet and there are plenty of good printed editions available as well. For its age, it's remarkably clear and concise even for modern readers. It's well-written and the author takes a very humble approach to the topic. As an argument it's a fantastic example of building to your conclusion by step after concrete step of irrefutable evidence. And when Darwin had to get speculative, he was correct an incredibly high percentage of the time, so even his wildest ideas still hold up today.
- ChemicalWarfare 10y ago>> The rules of the game force natural selection to exist. There is no other way it can work. care to cite a proven example of speciation caused by natural selection ?
- laurencerowe 10y agoLenski's famous experiment observed speciation in the lab: http://rationalwiki.org/wiki/Lenski_affair http://rationalwiki.org/wiki/Lenski_affair
- mratzloff 10y agoThanks for linking that. Interesting read about an experiment I hadn't heard of.
- ChemicalWarfare 10y agoDon't see any mentioning of speciation in that article. From the looks of it it's adaptation we're looking at, correct me if I'm wrong. To my knowledge, to date, the established experimental cases of achieving reproductive isolation (none achieving complete isolation btw)- no experiments demonstrated morphological differences between the "species" they produced.
- kirrent 10y agoI'll correct you because you're wrong. Adaptation is evolution. There's no line in the sand, no requirement for 'morphological differences', and no reproductive isolation before you call it evolution. Calling it adaptation is just a no true Scotsman fallacy.
- ChemicalWarfare 10y agoAre we not discussing the "origin of species" ? Sure, you can call adaptation "an evolution" in the same sense you can call a subset of something "something". Just because there's no evidence that natural selection leads to speciation it doesn't mean speciation in an of itself is not an important part of the evolutionary process unless of course you don't consider emergence of new species a part of that process. Defining a framework/requirement for "something" to be called "something" is not a fallacy, removing the requirement because it doesn't fit your narrative is though.
- kirrent 10y agoI misread your reply on Lenski's experiment as dismissing it as not an example of evolution, rather than as not an example of speciation. The first would be incorrect, the second is more of a judgement call which calls for discussion. If you did want a similar example in the same vein where speciation unambiguously occurred then one of Lenski's students just did a great experiment that shows that. I highly recommend reading it, it's a great paper. http://science.sciencemag.org/content/354/6317/1301 http://science.sciencemag.org/content/354/6317/1301
- aembleton 10y agohttp://darwin-online.org.uk/converted/pdf/1861_OriginNY_F382.pdf http://darwin-online.org.uk/converted/pdf/1861_OriginNY_F382...