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End game for Darwin’s finches?

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Galapagos Warbler/Luis Valente

Darwin’s finches, we are told, have reached their limits on the Galapagos Islands

From ScienceDaily:

The evolution of birds on the Galapagos Islands, the cradle of Darwin’s theory of evolution, is a two-speed process. Most bird species are still diversifying, while the famous Darwin’s finches have already reached an equilibrium, in which new species can only appear when an existing one becomes extinct. This finding expands the classical theory on island evolution put forward in the 1960s.

What? We haven’t even established how many “species” there are anyway, due to hybridization. Nonetheless,

‘The analysis shows that for the finches, diversity does indeed have a negative effect. There is no more room for new species, unless one of the existing species becomes extinct, so the islands are saturated regarding finch-type species’, Etienne explains. This does not mean the radiation is static. ‘We found that the rates of both evolution and extinction are very high for Darwin’s finches. That is probably why these birds have reached an equilibrium.’

Other species like mockingbirds have not yet reached equilibrium, which contrasts sharply with the current view that oceanic islands are at equilibrium. ‘Our data shows that they are evolving more slowly and are still diversifying.’ In a million years or so, more mockingbird species may have appeared — granted that conditions on the islands remain the same. More.

Again, what? Given that a huge hoo-haw ensued some years back when a minor climate change was supposed to be producing new species of finches within a researcher’s career, how likely is it that the conditions for a new species of mockingbird (a million years of eco-stasis) would be met?

I don’t suppose that’s a roundabout way of saying that evolution does not really occur in mockingbirds, but it almost sounds like it.

Here’s the abstract:

Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Galapagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Galapagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin’s finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms. Open access – Luis M. Valente, Albert B. Phillimore, Rampal S. Etienne. Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands. Ecology Letters, 2015; DOI: 10.1111/ele.12461

See also: Jonathan Wells on Darwin’s finches, among other tales:

Exaggerating the evidence to prop up Darwinism is not new. In the Galápagos finches, average beak depth reverted to normal after the drought ended. There was no net evolution, much less speciation. Yet Coyne writes in Why Evolution Is True that “everything we require of evolution by natural selection was amply documented” by the finch studies. Since scientific theories stand or fall on the evidence, Coyne’s tendency to exaggerate the evidence does not speak well for the theory he is defending. When a 1999 booklet published by The U. S. National Academy of Sciences called the change in finch beaks “a particularly compelling example of speciation,” Berkeley law professor and Darwin critic Phillip E. Johnson wrote in The Wall Street Journal: “When our leading scientists have to resort to the sort of distortion that would land a stock promoter in jail, you know they are in trouble.”

Actually, no, they aren’t. As long as science journalists prefer to be patted on the head and told they are good little cheerleaders rather than to ask serious questions, only science as such is in trouble.

The famous fourth estate (media) has, it seems, been inherited by wastrels and layabouts.

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Of related note: Darwin’s finches not a good example of Darwinian evolution? - February 12, 2015 Excerpt: The most extensive genetic study ever conducted of Darwin’s finches, from the Galapagos Islands, has revealed a messy family tree with a surprising level of interbreeding between species. It also suggests that changes in one particular gene triggered the wide variation seen in their beak shapes … 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.… “It’s been observed that the species of Darwin’s finches sometimes hybridise – Peter and Rosemary Grant have seen that during their fieldwork,” Prof Andersson told the BBC. “But it’s difficult to say what the long-term evolutionary significance of that is. What does it contribute?” What it contributes is that one would be hard pressed to show that there is any evolution going on, in the face of this much hybridization.,,, https://uncommondesc.wpengine.com/evolution/darwins-finches-not-a-good-example-of-darwinian-evolution/ Darwin's Finches: Answers From Epigenetics by Jeffrey Tomkins, Ph.D. - August 29. 2014 Excerpt: Just one year prior to this 2014 study,1 the epigenetic basis of speciation was demonstrated in birds in which the progressive geographical spread and ecological patterns of adaptation for a newly introduced songbird species were characterized by differences in DNA methylation patterns, not variation in the actual DNA sequence.2 In contrast, traditional Darwinian evolution alleges that random changes in the DNA itself generate new and useful variants that are then selected by the environment. In reality, researchers are now discovering that organisms can robustly adapt to different ecological niches without major changes in their DNA sequence.,,, What underlies this variation in finch beaks? In studies attempting to determine the molecular basis for beak variability in finches, researchers have found that very similar developmental genetic pathways among species can produce markedly different beak shapes.5 So if the genes are essentially the same, then what seems to be the major source of variation? In this current effort, the researchers studied two different factors in the genome. The first were short sections of non-coding DNA sequence that varied in the number of copies—repeated units—called copy number variants or CNVs. In humans, differences in CNVs form the basis for studying forensics and paternity testing. The second factor studied was epigenetically-based, using an analysis of DNA methylation patterns around the genome. From these analyses, the researchers found that epigenetics correlated well with increased diversity among species while CNVs, based on actual DNA sequences, did not. In addition, they also undertook a more focused study of the epigenetic profiles of specific genes involved in the morphogenesis of beak shape, immune-system responses, and coloring of the birds. Once again, the epigenetic profiles of the different bird species for all of these gene groups were different while the DNA sequences were nearly identical. In addition, the amazing cellular machinery that reads, regulates, replicates, and modifies epigenetic states in the genome is so incredibly sophisticated and complex that it can only be attributed to the work of an Omnipotent Creator. http://www.icr.org/article/8338/ Darwin's Finches Show Rule-Constrained Variation in Beak Shape - June 10, 2014 Excerpt: A simple yet powerful mathematical rule controls beak development, Harvard scientists find, while simultaneously preventing beaks from evolving into something else.,,, We find in Darwin's finches (and all songbirds) an internal system, controlled by a non-random developmental process. It is flexible enough to allow for variation, but powerful enough to constrain the beak to its basic form (a conical shape modulated by scaling and shear) so that the rest of the bird's structures are not negatively affected. Beak development is controlled by a decay process that must operate at a particular rate. It's all very precise, so much so that it could be modeled mathematically.,,, The very birds that have long been used as iconic examples of natural selection become, on closer examination, paragons of intelligent design. http://www.evolutionnews.org/2014/06/darwins_finches086581.html Darwin 'Wrong': Species Living Together Does Not Encourage Evolution - December 20, 2013 Excerpt: Charles Darwin's theory of evolution set out in the Origin of Species has been proven wrong by scientists studying ovenbirds. Researchers at Oxford University found that species living together do not evolve differently to avoid competing with one another for food and habitats – a theory put forward by Darwin 150 years ago. The ovenbird is one of the most diverse bird families in the world and researchers were looking to establish the processes causing them to evolve. Published in Nature, the research compared the beaks, legs and songs of 90% of ovenbird species. Findings showed that while the birds living together were consistently more different than those living apart, this was the result of age differences. Once the variation of age was accounted for, birds that live together were more similar than those living separately – directly contradicting Darwin's view. The species that lived together had beaks and legs no more different than those living apart,,, ,,,there is no shortage of evidence for competition driving divergent evolution in some very young lineages. But we found no evidence that this process explains differences across a much larger sample of species.,,, He said that the reasons why birds living together appear to evolve less are "difficult to explain",,, http://www.ibtimes.co.uk/darwin-wrong-species-living-together-does-not-encourage-evolution-1429927 bornagain77
Evolution can explain everything...... Andre
Might be end game for finches, but the Galapogos lizards still have a long way to go. Flap flap little lizard - gliding is for sissies. https://en.m.wikipedia.org/wiki/Draco_maculatus ppolish

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