Darwinism Confirmed! How? Finch Beaks Got Smaller!
Randolph E. Schmid of Associated Press (see ABC News) seems hardly able to contain his excitement. “Finches on the Galapagos Islands that inspired Charles Darwin to develop the concept of evolution,” he wrote, “are now helping confirm it by evolving.” This sounds like big news. How, exactly, are they evolving? “A medium sized species of Darwin’s finch has evolved a smaller beak to take advantage of different seeds just two decades after the arrival of a larger rival for its original food source.”
There is no question that Darwin’s finches on the Galapagos Islands have achieved iconic status. Charles Darwin believed that the 13 species (although the term species is loosely applied, since many are interfertile) originated from one ancestral species on the mainland. All the species are quite similar except for the size and shape of their beaks. Books have been written on this group of birds, often called the best example of natural selection at work in the wild. Now, according to the Associated Press story, we have witnessed the action of selection in just 24 years.
A Princeton husband-and-wife team has devoted 33 years of study to documenting the evolution of Darwin’s finches. Peter and Rosemary Grant published their latest paper this week in Science1 (see earlier work in 08/24/2005, 09/03/2004, 04/26/2002 entries). In 1982, the large ground finch (Geospiza magnirostris) invaded Daphne island, posing competition to the medium ground finch (G. fortis) that ruled the roost there. The competitor ate them out of house and home. Because of the new food fight, G. fortis beaks shrunk so that they could adapt to eating alternate food, the seeds of cacti and other plants.
A specific morphological change caused by competition is termed character displacement – in the Grants’ words, “an evolutionary divergence in resource-exploiting traits such as jaws and beaks that is caused by interspecific competition.” They judged this change of beak size in G. fortis, due to the competition from G. magnirostris, “the strongest evolutionary change seen in the 33 years of the study.” Sounds like a Q.E.D. in the bag. The mean change in beak size was about 0.7 standard deviations, “exceptionally large” in their view (actually, it represents a shrinkage of less than a millimeter on average, or 5%). Nevertheless, they hedged, the “evolutionary changes that we observed are more complex than those envisaged by [D.] Lack” who had published a book on Darwin’s finches in 1947 on the role of competition in selection. That’s because other factors were implicated in the population dynamics of the birds.
Surprisingly, they said no one ever studied this before, here or anywhere else. “The process of character displacement occurring in nature, from the initial encounter of competitors to the evolutionary change in one or more of them as a result of directional natural selection,” they began the paper, “has not previously been investigated.” That seems very surprising, almost shocking, given the fame of these finches and how they are used to support Darwin’s theory, to say nothing of the wide acceptance of Darwin’s theory itself and the number of evolutionary research studies performed around the world since 1859.
Yet even with this apparent success, the Grants cautioned that “Replicated experiments with suitable organisms are needed to demonstrate definitively the causal role of competition, not only as an ingredient of natural selection of resource-exploiting traits but as a factor in their evolution.” That seems to suggest that this 33-year experiment did not establish a definitive cause-and-effect relationship between competition and natural selection, or clear evidence for evolution, either.
Nevertheless, Elizabeth Pennisi in the same issue of Science2 summarized the work in glowing terms:
Evolutionary biologists consider the paper important because it demonstrates the interplay between population numbers and environmental factors: The shift in beak size occurred only when there were enough large ground finches and large seeds were scarce enough to cause a problem, says [David] Pfennig [evolutionary biologist at U. of North Carolina]. “This study,” he adds, “will motivate researchers to go into the field and see if they can document other examples of character displacement in action.”
Pennisi also quoted a biologist who feels this study “will be an instant textbook classic.”
1Peter R. Grant and B. Rosemary Grant, “Evolution of Character Displacement in Darwin’s Finches,” Science, 14 July 2006: Vol. 313. no. 5784, pp. 224 – 226, DOI: 10.1126/science.1128374.
2Elizabeth Pennisi, “Competition Drives Big Beaks Out of Business,” Science, 14 July 2006: Vol. 313. no. 5784, p. 156, DOI: 10.1126/science.313.5784.156
Folks, ignore the hype and look at the data. There were already specimens of medium ground finches on Daphne with beak sizes in the final range. The shrinkage was less than a millimeter, on average! The only evolution was in the relative numbers of birds with an average length of 10.6 millimeters instead of 11.2 millimeters, and an average depth of 8.6 millimeters instead of the 9.4 millimeters before. That’s it! This is what evolutionary biologists are proclaiming as a textbook classic? If this is all the textbooks can point to as actual field evidence for Darwinian evolution, our students need alternatives.
Any fair-minded reader of the Grant paper would have to ask some very serious questions about the methodology used and the empirical quality of the research, and especially what it signifies. The Grants are very good at measuring beaks down to the submillimeter range, but think of the problems. The numbers of birds counted varied drastically from one year to the next. How did they know they were getting an adequate sample? Were they taking into account the age of the birds, assuming that beak size could vary in individuals throughout their lifetimes? Think how much your beak has changed since you grew up. How much did their presence and picking up the birds to measure them influence the poor critters’ fitness? Peter and Rosemarie claimed to have ruled out all factors other than natural selection, but remember, this is their life work to shore up evidence for Charlie darling. How much does their need for success and fame play into their findings? Their dedication to this work is admirable, but human nature strongly influences the NSF grant money (if you’ll pardon the expression) and desire to bring back the goods when you want to honor your alma mater and go down in history as the best researchers on the most famous icon of evolution. Even assuming their honesty, they couched their conclusions with safety valves and downplayed the significance of the study, saying more work is needed.
Yet the news media, as usual, chirped up a storm over any hint of a suggestion of a possibility that Charlie has (finally) been vindicated. “Darwin’s finches evolve before scientists’ eyes,” writes Sara Goudarzi triumphantly in LiveScience, echoed on MSNBC. The only glimmer of hope in this media circus is that it somehow seems less bombastic than before. Some of the other usual Darwin trumpets (New Scientist, BBC, National Geographic) chose not to sound off on this song for some reason. Maybe they knew they would get a thrashing on the blog. Update 07/15/2006: well, we spoke too soon. National Geographic, naturally, fell for this story hook, line and sinker. In a stupidly gullible report, Mason Inman wrote about “instant evolution” and won Stupid Evolution Quote of the Week with this groaner:
David Pfennig at the University of North Carolina at Chapel Hill agrees that the study has important implications.
For Pfennig, the study’s greatest surprise was “the apparent speed with which the character displacement occurs—within a single year!”
Usually we think [sic] of evolution as being a slow grind, he says.
But, Pfennig added, the study suggests that evolution due to competition between closely related species “paradoxically may often occur so rapidly that we may actually miss the process taking place.”
So, evolution is usually so slow we can’t see it, but then it happens so fast we may miss it. In no other avenue of life where truth claims are debated would such flimsy evidence get any respect. Beaks shrink, and thus prove natural selection can create scientist brains from a chemical soup. This is plain silly. What will our grandchildren think? We document this stuff to show that at least some people in 2006 still had their heads screwed on, otherwise historians may wonder what caused the mass imbecility back then.
In their lists of references and quotations, the Grants (and the media) did not even pay one ounce of attention to the long and loud disputations by creationists and intelligent-design leaders about the finch beak problem. From Duane Gish to Jonathan Wells and beyond, reputable scientists not polluted with Darwin addiction have argued that this is not evolution! David Berlinski (no Christian fundamentalist) said that this evidence doesn’t even rise to the level of anecdote. If Darwin gave us the great theory to which we are all supposed to give our allegiance, the best idea anyone ever had, the only theory worth mentioning in the science classroom, then we are going to need a lot better evidence than finch beaks varying by less than a millimeter in response to climate and food supply. Neo-Darwinism by mutation and natural selection is supposed to explain all the complexity of life from ameba to man, and they get excited about beak size? Come on!
Lest someone at Panda’s Thumb or Pharyngula get self-righteously indignant about our picking on Darwin’s finches without mentioning the “mountains and mountains of evidence” throughout biology, remember, that numerous evolutionists have pointed to Darwin’s finches as the best example of natural selection ever found. This means that all the other examples are weaker and less convincing. Not only that, the other studies on these same finches have produced nothing more than oscillating changes around a mean, certainly dubious as evidence that birds evolved from pre-bird ancestors.
Weak evidences do not add up. A thousand buckets of sand do not provide a strong foundation. This is especially true when other interpretations of the evidence are available. Only a commitment bordering on religious zeal would look at this evidence as confirming of evolution over the common-sense interpretation that these birds look designed. They fly, they digest food, they reproduce, they have eyes and ears and whole systems of complex, interrelated parts. Under the most favorable light, the Darwinists might be able to claim that existing small beaks became more predominant when the food was gone. OK, even creationists buy that. Now tell us about the rest of the bird, please.
This nonsense continues because the gurus of the Cult of Darwin have safely ensconced themselves in the castle of academia, renamed it Daphe, and have barred entry to all who will not swear the oath of allegiance to King Charles the Usurper. But now we have the internet. It’s going to take an army of persistent Visigoths to storm the walls (cartoon and 05/09/2006 entry) and restore truth and justice. From outside the castle, the evidence is accumulating for Darwin’s flinches. We’ll Grant them that. Once inside, we shall see if a little competition forces their beaks to shrink.