Joined: Oct. 2009
|Quote (oldmanintheskydidntdoit @ Dec. 12 2011,11:25)|
|Quote (Southstar @ Dec. 12 2011,11:05)|
|I don't want a lab study that would show complete evolution, it would be sufficient to show that a morphological mutation that occured due to novel genetic material was selected by natural selection and was passed down to a new species.|
|But sometime around the 31,500th generation, something dramatic happened in just one of the populations - the bacteria suddenly acquired the ability to metabolise citrate, a second nutrient in their culture medium that E. coli normally cannot use.|
Indeed, the inability to use citrate is one of the traits by which bacteriologists distinguish E. coli from other species. The citrate-using mutants increased in population size and diversity.
"It's the most profound change we have seen during the experiment. This was clearly something quite different for them, and it's outside what was normally considered the bounds of E. coli as a species, which makes it especially interesting," says Lenski.
But sure, they will just say they are still "bacteria", not a new species (whatever that might mean).
But Lenski had exactly what you are asking for, novel genetic material promoted by selection and passed down to form a new species.
Another example: http://www.nature.com/nature.....a0.html
|Sympatric speciation by the formation of host races (parasite populations associated with different plant or animal hosts) has been the subject of great controversy. It has been difficult to demonstrate the existence of host races1,2, much less to prove that host races are evolving toward species status. Genetic polymorphism attributable to association with different resources does occur3, but the phenomenon is far from ubiquitous in parasite populations. The apple maggot fly Rhagoletis pomonella uses a variety of host plants, and Bush4,5 has argued that it is a likely candidate for speciation by a sympatric mode. So far however there has been no direct evidence of any genetic differentiation between host-associated fly populations. We report significant differences in allele frequencies between fly populations reared from sympatric apple (Mains pumila) and hawthorn (Crataegus mollis) trees at a field site in Urbana, Illinois, in the United States.|
In any case Darwin already provided what you are looking for here, in effect: http://en.wikipedia.org/wiki.......finches
|Developmental research in 2004 found that bone morphogenetic protein 4 (BMP4), and its differential expression during development, resulted in variation of beak size and shape among finches. BMP4 acts in the developing embryo to lay down skeletal features, including the beak. The same group showed that the different beak shapes of Darwin's finches develop are also influenced by slightly different timing and spatial expression of a gene called calmodulin (CaM). Calmodulin acts in a similar way to BMP4, affecting some of the features of beak growth. The authors suggest that changes in the temporal and spatial expression of these two factors are possible developmental controls of beak morphology.|
Give it more time and they won't be able to interbreed because of the beak sizes and you have what you want. Long after we're all dead, but evolution is (usually) slow at the species level.
Actually, the arguably a new species by most meaningful definitions of the word.
The collection of bacteria we call E. coli can have up to 80% genetic variation. That's way more than any equivalent non-bacterial species.
But one of the defining characters of E. coli is the inability to utilize citrate. That is how doctors determine if you have Salmonella poisoning or E. coli poisoning. They grow the sample on citrate. If it grows, then it is Salmonella.
So, you have a bacterium with a very novel feature, one, by definition, it shouldn't have.
If Lenski ever writes a paper describing his strain as a new species, there would probably not be anyone complaining about it.
Ignored by those who can't provide evidence for their claims.