"Imagine spending 40 years of your life promoting Darwinian evolution with Galapagos finches, only to find out on Darwin Day that the birds hybridize and cross-breed.
It’s Darwin Day, in case anyone noticed. Charles Darwin’s birthday hasn’t quite become the global holiday some of his ardent devotees have wished. (It’s also Abraham Lincoln’s birthday in America.) What better way to remember Darwin than with a fresh look at his iconic finches from the Galapagos Islands?
A new paper came out in Nature about Darwin’s finches, suspiciously timed for Darwin Day. It
describes genome comparisons of 120 individual birds from various Galapagos islands and the mainland, comprising 15 species of finches. The results are hardly supportive of Darwin’s main theory of biological innovation by an unguided mechanism (more on that in a bit), but the mere mention of Darwin+finch is bound to give the reporters a high:
Some scientists were surprised to find so much gene mixing. The BBC article continues:
It’s Darwin Day, in case anyone noticed. Charles Darwin’s birthday hasn’t quite become the global holiday some of his ardent devotees have wished. (It’s also Abraham Lincoln’s birthday in America.) What better way to remember Darwin than with a fresh look at his iconic finches from the Galapagos Islands?
A new paper came out in Nature about Darwin’s finches, suspiciously timed for Darwin Day. It
- DNA Reveals How Darwin’s Finches Evolved (National Geographic)
- Evolution of Darwin’s finches and their beaks (Science Daily)
- A gene that shaped the evolution of Darwin’s finches (Princeton press release)
- Genomes of Darwin’s finches may explain the shape of human faces (Science Magazine)
Messy history
The study also revealed a surprisingly large amount of “gene flow” between the branches of the family.
This indicates that the species have continued to interbreed or hybridise, after diversifying when they first arrived on the islands.
The researchers looked for genetic bases for diversification, and honed in on one gene named ALX1 that appears to be implicated in beak changes. It’s not completely responsible, the articles point out; it’s just one gene of several involved in beak formation. In humans, mutations to this gene is implicated in facial deformations such as cleft palate. It’s not giving humans any evolutionary advantage, in other words.Some scientists were surprised to find so much gene mixing. The BBC article continues:
Other geneticists have expressed mixed reactions to the results. Dr Julia Day, from University College London, was impressed by the level of mixing reported between the finch species — which she said are “a textbook example of radiation”.
She told the BBC: “The fact that they’re finding this hybridisation going on — this genetic mixing — it’s quite a seminal finding.
“When you look at their results, you can see the trees are quite messy, in terms of the traditional species groupings.”
Another was not surprised. The birds have wings, after all, and can fly between the islands. None of the articles mentioned that creationists are not surprised, either. They allow for variations in beak size and feather coloration, just like they see wide variations in dogs and cats. They just point out that the finches are still finches: beaks, wings, eyes and all. Nothing new, requiring new genetic information, has evolved. In fact, the variability in beaks is more pronounced when the finches interbreed, restoring the inherent variability in the ALX1 gene and other genes. This implies that some variants can become genetic dead ends; they lose genetic information." CEH
And God created ...every winged fowl after his kind: a
nd God saw that it was good.
Genesis 1:21
