A landmark study on contemporary evolutionary change in natural populations released by an international team of researchers led by Texas A&M University professor Dr. Leif Andersson reveals that 45% of the variation in the highly heritable beak size of Darwin’s finches can be attributed to only six genomic loci (fixed positions on a chromosome). Among these is a supergene that comprises four genes, which was under strong natural selection as a result of a two-year drought.
A reasonable explanation for the presence of large-effect alleles in Darwin’s finches is that these have evolved over time by the accumulation of multiple causal mutations as a response to diversifying selection.
Hmmm…
Why is diversification of small number of vertebrates after a flood 4-5 millennia ago leading to the species we see today improbable when only SIX(!) loci have such a great effect on the phenotypic separation of these finch species?
This is probably the longest observational study of evolution ever done that included genetic analysis? Pretty cool.
There are nothing close to 4-5 millennia available. It is debatable if there are a few decades. Ancient Egyptian art and mummification tells us that cats had differentiated to modern forms before the patriarchs. The Hebrew scriptures already refer to specific species of canines, cats, and antelope, and the Pentateuch has Adam naming them. Then there is the endless list of now extinct relatives which outnumber their modern counterparts, the mammoths, giant sloths, camels, bears, saber tooth cats, crocodiles, elephants, rhinos, and marsupials, all of which supposedly adapted to their post flood environs, in a matter of few generations multiplying and filling the Earth, only to promptly up and go extinct.
But given millions of years? Why would you think diversification of vertebrates leading to the species we find now and in the fossil record, to be improbable by evolutionary mechanisms in that expanse of time, if phenotype separation due to such few mutations is evident in real time?
It does? I can’t see it. A “gradual change toward blunter beaks” over 30 years justifies the idea of multiple genera splitting off in a few hundred (if that)? Really? Evidence that a new genus had emerged since Darwin’s visit would be something. This is not.
The six loci are called out because they have a significant affect on the beaks - and because that’s unusual. Which means it can’t be widely extrapolated - the unusual is, by definition, not the norm
To know and not to know, to be conscious of complete truthfulness while telling carefully constructed lies, to hold simultaneously two opinions which cancelled out, knowing them to be contradictory and believing in both of them, to use logic against logic, to repudiate morality while laying claim to it, to believe that democracy was impossible and that the Party was the guardian of democracy, to forget whatever it was necessary to forget, then to draw it back into memory again at the moment when it was needed, and then promptly to forget it again, and above all, to apply the same process to the process itself—that was the ultimate subtlety: consciously to induce unconsciousness, and then, once again, to become unconscious of the act of hypnosis you had just performed. Even to understand the word—doublethink—involved the use of doublethink.
