Microbes use arsenic in their DNA:  Proves phosphorus is not required for life
Don't mean to get all religious on ya, but I wanted to ask here...<p>Is there any evidence of macro-evolution having ever taken place in recorded history? I'm asking this with no agenda, but curious. As far as I know, no new species have ever been produced, despite natural or unnatural selection.<p>So what makes us say that there is no other force or process that causes speciation? How are scientists so convinced that mutation and natural selection is all that is required, despite never having observed a single instance of speciation?<p>To be scientific, a theory has to make some potentially falsifiable, non-obvious predictions. Then we can test those predictions, and if our experiments confirm them then the theory survives. I totally agree that the hypothesis "natural selection occurs" has been proven in ample ways (ok, maybe the white->dark->white butterflies was a bad one, but bacteria and their resistance to antibiotics is proof enough). But to form a completely new species...<p>Species is defined as "as a group of organisms capable of interbreeding and producing fertile offspring" according to Wikipedia. Two animals are of different species if none of their offspring have ever been observed to be fertile. At least, that's a good working definition.<p>It bothers me that scientists have been interbreeding literally thousands of generations of fruit flies and despite all selection pressures, artificial or not, were never able to produce a single new species. Sure, it's hard to try and mate every fruit fly with every other fruit fly, so maybe there were divergent species, but after a few generations, this should have revealed itself. If this is really the case, then how come we take it for granted that humans, homo erectus, neanderthals etc. were all divergent species that had a common ancestor something like 50,000 years ago? Am I way off? If you take the fruit fly lifetimes and human lifetimes, in those 50,000 years we had about as many generations as the fruit fly generations. And we got all this speciation supposedly, using nothing more than mutation and natural selection. But where is the proof?<p>I'm not necessary arguing that one of the religions is right and there is another force. But are scientists being biased here when they simply assume there isn't any other force? It's as if I was looking at cars from the 1920s all the way up until now, and I saw gradual change, and based on this I decided that there was no designer of these cars. I don't think that follows at all.<p>Just curious if someone knows links that can resolve this for me :)