Evolution caught in the act
Smaller beaks in Galápagos finches make finding food easier.
Competition between two species of finch in the Galápagos has caused the beak size of one species to shrink, and scientists have watched it happen. Detailed observations of the birds, which Darwin famously studied while formulating his theory of evolution, have provided one of the best descriptions of a characteristic trait evolving in the wild.
Read the story here.
Comments
In the article "Evolution Caught in the Act" is that which has been observed by the authors Peter and Rosemary Grant attributable singularly to evolution-in-progress or possibly more precisely to an evolutionary adaptation already completed by the finches? In other words do the finches, as part of an evolutionary adaptation, have an evolutionary predisposition to vary their beak size such that as a species they are ensured to succeed in harsh, rapidly-altering environments?
Posted by: Richard Daugert | July 17, 2006 08:02 PM
Peter R. Grant and B. Rosemary Grant had reported in 2002 (Science 296:707-711) results of the same study for the period from 1973 to 2001. In the present article (Science, 313:224 - 226) one cannot find new information added to what has already been reported by them. The conclusion that evolution of beak size suiting the food source has taken place in too short a time as couple of years is something difficult to swallow – certainly not the kind Darwin envisioned. There is a growing tendency among researchers to explain every observation in the light of evolution. This will only help create more doubts about Darwin’s theory. The observations made by Grant et al. can be more effectively and logically interpreted based on cell-directed mutagenesis (reported in 1988 by Cairns et al.) rather than an evolution event and would have avoided unnecessary introduction of new concepts; in this case “character displacement”. The evolutionary literature is already crowded with concepts of every conceivable shade. Depending on the environment, the genetic switch operates bringing in the required mutation (not random but specific to the stress) to tide over the situation. Bigger or smaller beak develops that way. Necessary genetic information is already available with the species. This is comparable with the well-documented phenomenon of resistance development in insects and other organisms against pesticides. This hypothesis is falsifiable through the reversal of the change in character by restoring the original environmental condition. If variation in beak size is considered an evolution event, large variations found in human traits should provide much better evidence of evolutionary phenomenon.
Posted by: P.A.Wahid | July 18, 2006 04:35 AM
I'm used to seeing specious arguments from Darwinists desperate to support their dogma and justify their research grants, but this is the most absurd reasoning I have ever come across.
Put aside the extraordinary fact that the beginning of the article says that the bigger beak of the larger "species" was an advantage and that in the drought conditions for some unspecified reason smaller beaks became an advantage, just look at the "reasoning."
The smaller beak was a survival advantage. Therefore birds with small beaks survived to breed the next season. So the newly hatched chicks had small beaks!! Wonderful! What's the surprise in that?
Humans have been using the knowledge that this happens for at least 6,000 years. We brought very small dogs into existence by using the very same technique - and very big dogs.
That's not evolution! It most certainly is not the passing on of acquired characteristics (the impossibility of which sank Lamarck's theory of evolution) because the small beaks were not acquired. It is a very limited application of natural selection, but no-one has ever doubted that species and types which don't survive are unable to pass on their genes. That hardly needs proving.
This article is sheer nonsense dressed up as wonderfully revealing research.I'm gobsmacked that a respected publication could include such ???
Posted by: Peter Smith | July 18, 2006 10:03 AM
There seems to be confusion as to what this article is presenting and why it is important. It is easier to quote science writer James Hrynyshyn from his blog:
"But the Grants never set out to prove evolutionary theory. The "this" in Pennisi's story isn't evolution itself, but one of the details of the mechanisms behind evolution. In the current paper, the Grants deal with a process until now never documented called "character displacement," in which one characteristic of a species changes in response to competition. In this case, the character is beak size: when times got tough, the beaks shrank, as the finches with larger beaks died off and those with smaller beaks fared better."
Reading the Grant's paper carefully will clear up any other misinformation.
Posted by: Cameron Peters | July 19, 2006 10:23 PM
There appears to be some confusion about the meaning of "evolution" as expressed in several posts and understandably also in the baby boomer generation who were raised on a steady diet of pro-evolution biology teachings. This dilemma may arise from lumping Darwin's two major contributions into one theory rather than the two separate entities that they rightfully are: Darwin's theory of adaptation and survival of the fittest within and among species, also known as microevolution, which is firmly founded on solid observational facts, and his speculative extrapolated theory of evolution pertaining to inter-species transitions and transformations from less complex life forms, also known as macroevolution or Darwinism.
Darwin's microevolution theory has a solid foundation and constitutes a major scientific contribution for which he rightly deserves high honors. But his macroevolution theory of the origin of complex life forms, especially the descent of man, is more intuitive extrapolation than scientific theory, thesis or even hypothesis, all of which demand experimental verification that is woefully lacking and, in fact, unobtainable. Supporting this negative assessment of Darwinism is the fact that it violates the natural law of entropy. Hence, these two Darwinian theories, one scientific and the other non-scientific, need to be kept apart in any discussion of the flaws in Darwinism that, I believe, will eventually cause Darwinism to self destruct even without the alleged “mudslinging” by the proponents of Intelligent Design or Creationism.
More recent discoveries, unknown to Darwin and his contemporaries, further peg Darwinism as a flawed theory, e.g. the paucity of credible transition species, the inability to account for the genesis of the genetic code and DNA, and the lack of a rational evolutionary mode for numerous species exhibiting what has been termed "irreducible complexity", i.e. inter-species transitions demanding concurrent transformations that could not logically or statistically have occurred in any time frame by stepwise random processes (Intelligent Design and its cornerstone, irreducible complexity, though largely dismissed or ignored by scientists, the courts, and even the Vatican, is gaining wider acceptance on several university campuses where I.D. chapters have been started).
A prime example of irreducible complexity is the superbly designed complex "gun" organ in the bombardier beetle that mixes highly reactive chemicals in a perfectly timed sequence to create multiple powerful audible gun bursts over a few milliseconds without any detectable recoil or harm to the beetle. It is inconceivable that such an intricate mechanism could have evolved! Even Darwin apparently anticipated the complexity issue by allegedly stating: "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."
Darwin's macroevolution theory has further been proven statistically highly improbable in light recent findings in the Human Genome Study published in 2003. Conservation of genetic homology in homo sapiens was reported to be about 99.9%, in which the remaining 0.1% encompasses all genetic and racial traits. But human homology has been reported elsewhere to differ from our nearest mammalian “kin” by an astounding and probably unbridgeable 5-8% difference!
In light of these and other seemingly insurmountable obstacles, Darwinism must thus be classified as a scientifically and statistically highly improbable
extrapolation based on intuition and wishful thinking quite akin to the proverbial "blind faith" in the greatly despised Intelligent Design and Creation constructs, not theories. I am inclined to support the arguments of some proponents of I.D. that Darwinism is a variant of the medieval theory of "spontaneous generation", i.e. conversion of mud to maggots in a mega-millennial time frame. This theory had been dispatched by Darwin's contemporary, Louis Pasteur, who also strongly opposed evolution as lacking scientific evidence.
Regarding the teaching of evolution, I suggest that teachers critically present the pros and cons of Darwinism and simply state the fact that is it a flawed, but currently best pseudo-scientific explanation, not a scientific theory, of the origin of species. The objective teacher may want to challenge his students to come up with an alternative truly scientific theory, an achievement worthy of a Nobel Prize. There is no need to discuss or teach Creationism or Intelligent Design, both of which are plausible, albeit highly controversial and thus unacceptable faith-based alternatives. But, in my opinion, an unbiased exposition of the failures of Darwinism may lead the inquisitive student to examine supernatural origins of species as equally irrational alternatives to Darwinism. Such alternatives may be optionally based on Mother Nature, a Star Wars-like extraterrestrial Force, or an omniscient God who started it all, but chooses not to tell us fully why or how He did it.
Posted by: Herman Rutner | July 25, 2006 11:46 PM
Some of the last comments are a mix of incomprehension and misleading interpretation aimed at supporting non-scientific views. While it seems appropriate to keep forums such as this open to individual opinions, its very nature, it strikes me the editing had not restricted such blatant attacks on the theory of evolution by religious outsiders of the scientific community. For example, claiming that Darwinism is not “scientific theory, thesis or even hypothesis” seems to be trying to diminish the value of hypothesizing in science. Biological evolution will always be a hypothesis in the widest sense, open to refutation, as much as Relativity now, Heliocentrism in its time and any other established (but not immutable) scientific theory. It is just that refutation for NeoDarwinian evolution as a whole and better explanations than that of evolution to phenomena like beak size changes in finches had never been presented.
Posted by: Milton Mendonça Jr. | July 26, 2006 03:38 PM
Darwins theory of evolution is only supported by the discoveries in Darwin's finches. The small beak finches and the bigger beak finches all originated from the original finch that came to the Galapagos. the fact whether or no the small beak generation evoled in to a big beak generation backs up the fact that darwins theory of evolution is drived by natural selection, so assuming that in one generation was small beaked was more successful then a larger beaked bird, then the smaller beak birds species is going to have a greater survival amount then the big beaked birds. thus allowing more of the small beaked birds to reproduce successfully in comparison to the larger beak birds, and vice versa. Evolution is normally one organism evolving into a new species, but in this case it shows two different species, that are seperated by a single trait and shows signs of similar ancestry, That are surviving differently from generation to generation. This is a great example of evolution because it shows to senarios that caused one finch species to envolve into two species, maybe not the species evolving from small beak to large beak in one generation but it shows organisms that are able to survive will reproduce more then the organisms that had to struggle.
Posted by: Bob Wakefield | May 10, 2008 06:21 AM