Tag Archive for 'darwinism'

The Edge of Evolution

The Edge of Evolution

The Edge of Evolution, by Michael J. Behe
The Free Press, 2007
336 pages
Amazon.com link

More than a decade ago, in 1996, Michael Behe published Darwin’s Black Box. In it, Behe argued that Darwinian evolution is impossible: random mutation and natural selection cannot account for the intricate, irreducibly complex systems that make life possible. These systems–such as the way blood clots in mammals–are essential to life, and are made up of dozens–even hundreds–of parts. If even one part is missing, the system is useless and the creature dies. Behe argued that it is impossible for random mutations to build these irreducibly complex systems up piece by piece, step by step.

In 1996, Behe could offer no actual evidence for the impossibility of Darwinian evolution. All he offered was the idea of irreducible complexity. In the decade since Darwin’s Black Box, studies of mutation rates have furnished Behe with real-world data to support his earlier conclusions. In a new book published earlier this year, The Edge of Evolution, Behe uses scientific data to reveal what Darwinism can and cannot accomplish.

Definition of terms
Behe begins The Edge of Evolution by defining some terms. The word Darwinism encompasses three distinct ideas:

  • common descent
  • natural selection
  • random mutation

Common descent is the idea that all living creatures have similar features that were inherited from a common ancestor. For example, dolphins and whales are descended from a common ancestor, as are dogs and cats, and even elephants and mice. “Common descent is what most people think of when they hear the word ‘evolution,’” says Behe. But common descent is not the full story.

Common descent tries to account only for the similarities between creatures. It merely says that certain shared features [e.g., complex cells with nuclei] were there from the beginning–the ancestor had them. But all by itself, it doesn’t try to explain how either the features or the ancestor got there in the first place, or why the descendants differ.

This brings us to Darwin. Darwin’s theory is that small random mutations, coupled with the mechanism of natural selection, can account for all the forms of life on earth. Natural selection means simply survival of the fittest: the creatures that have some natural advantage will produce more offspring, and thus pass on their natural advantages. Random mutations introduce small changes; natural selection weeds out the useless and harmful mutations; the beneficial mutations survive. Eventually, a lot of small changes add up to big changes–and thus life evolves into different forms and species.

So Darwinism means common descent by means of random mutation and natural selection. If Darwinism is true, all three ideas must be true, and they must be sufficient to account for all the different forms of life on Earth. Behe considers the DNA evidence in support of common descent to be overwhelming, and he does not dispute its truth. Random mutation and natural selection have been studied, and they “can modify life in important ways.” But not in ways sufficient to account for the origin of species, Behe concludes. For proof, he turns to some real-world studies of mutation rates in the malaria parasite.
Continue reading ‘The Edge of Evolution’

Living With Darwin

Living With DarwinLiving With Darwin: Evolution, Design, and the Future of Faith, by Philip Kitcher
Oxford University Press, 2007
Pages: 166

In a slim book, Philip Kitcher explores the history of religious objections to Darwinism, and attempts to explain why evolution is a threat to religion. He succeeds on the first count, but his ramblings on the second part are cringingly poor.

Kitcher starts by explaining that objections to Darwin fall into three categories, which he labels Genesis creationism, novelty creationism, and anti-selectionism.

Genesis creationism, which holds the biblical account to be literally true, was “discarded, consigned to the large vault of dead science” by the 1830s. Kitcher points to the scientific evidence that doomed the literal interpretation of Genesis: geological evidence of an old earth, the implausibility of a global flood, and the ordering of fossils into strata showing different organisms at different stages in earth’s history.

By Darwin’s time, the scientific community generally accepted an old earth and a non-literal interpretation of Genesis. The main theory opposing evolution was novelty creationism, a concept that accepts “the ancient age of the earth but challenge[s] the relatedness of all living things and the power of natural selection, at least in the most important events in the history of life.” Novelty creationism allows for evolution on some scale, but states that the major transitions are miraculous acts of creation by God. Where evolution posits that all living things are related and belong to a single tree of life, novelty creation suggests that there are many independent trees of life, each created by God.

Novelty Creation and the Rise of Darwin
In the mid 1800s, one of the biggest proponents of novelty creation was Charles Lyell. In 1859 Darwin published his seminal work Origin of Species, which offered an explanation for evolution that rejected novelty creationism and showed how random mutation and natural selection could account for the creation of new species. The superiority of Darwinism over novelty creationism quickly became evident, and–as Kitcher points out–even Lyell “appreciated the point.”

As Lyell saw so clearly, once you admit that there have been different types of organisms on the earth at different historical stages, there are just two possibilities. Either the new ones come from the older ones, or the new ones spring from a new creative act. Darwin’s long argument showed the Lyell had picked the wrong option. Recognizing a single tree of life can account for innumerable details of the organic word that Creationism can only regard as the whimsy of Intelligence–and Lyell himself appreciated the point. With the explosion of detail in the century and a half since, coupled with the continued explanatory bankruptcy of the creationist program, intellectual honesty requires that one follow Lyell’s honorable lead.

Reacting to Darwin: Anti-Selectionism
The third kind of objection to Darwinism is anti-selectionism. Unlike novelty creation, anti-selectionism does not challenge the relatedness of species or deny the one tree of life. Instead, anti-selectionism denies that natural selection is capable of producing new species. One form of anti-selectionism is typified in Michael Behe’s book Darwin’s Black Box. He points to what he calls irreducibly complex systems, such as the flagella of bacteria. The flagellum is made up of so many interacting parts that it could not possibly have arisen by chance: any part of the system would be useless–and even harmful–on its own, so natural selection would weed out those mutations. The only way a flagellum could evolve would be for it to appear out of whole cloth, complete in every detail. The chances of such a mutation arising by random chance are so small as to be impossible, even if one accepts an earth that is billions of years old. The fact that flagella (and other irreducibly complex systems) exist is evidence that evolution is guided by an Intelligence, not by random chance.

Anti-selectionism is more difficult for Kitcher to discard to the “vault of dead science,” but he spends forty pages detailing the problems with anti-selectionism. Basically, it boils down to this: anti-selectionism uses baseless assumptions about probability that do not reflect reality. Scientists who have studied mutation rates have come up with numbers that suggest the timescale of evolution on Earth is sufficient to allow the development of species purely through the mechanism of random mutation and natural selection.

Evolution and the Threat to Religion
Kitcher spends the final chapter offering a muddled explanation of why evolution is such a threat to religion. He describes traditional Christianity as a providentialist religion–one that recognizes a Creator who “cares for his creatures, who observes the fall of every sparrow and who is especially concerned with humanity.” Evolution is incompatible with this view of a loving God, Kitcher claims, because evolution cannot operate without pain and suffering. What happens if we believe in a providential God and in evolution?

The general inefficiency of the processes [of evolution], the extreme length of time, the haphazard sequence of environments, the undirected variations, the cruel competition through which selection so frequently works, is all foreseen. And the individual nastiness to which Darwin points are expected outcomes of deploying these sorts of processes. If we search the creation for clues to the character of the Creator, a judgment of whimsy is a relatively kind one. For we easily may take life as it has been generated on our planet as the handiwork of a bungling, or chillingly indifferent, god.

[A] just Creator cannot consign vast numbers of its creatures to pain and suffering because this will promote some broader good. Divine justice requires that the animals who suffer are compensated, that the suffering isn’t simply instrumental to the wonders of creation but redeemed for them.

Kitcher suggests that the only way to reconcile religion with the facts of evolution is to reject providentialism and adopt a view he calls spiritualist religion.

Spiritual Christians abandon almost all the standard stories about the life of Jesus. They give up on the extraordinary birth, the miracles, the literal resurrection. What survive are the teachings, the precepts and parables, and the eventual journey to Jerusalem and the culminating moment of the Crucifixion. That moment of suffering and sacrifice is seen, not as the prelude to some triumphant return and the promise of eternal salvation–all that, to repeat, is literally false–but as a symbolic presentation of the importance of compassion and of live without limits. We are to recognize our own predicament, the human predicament, through the lens of the man on the cross.

Kitcher realizes that spiritual Christianity is vulnerable to criticism–after all, he’s thrown out the authority of scripture, so his religion is based on nothing but whims–but is unable to offer any real defense. What Kitcher proposes is nothing more than a complete rejection of biblical Christianity; he picks and chooses the scriptures he likes, and assembles meaningless mishmash. And he does this for no good reason: just because Kitcher is personally unable to reconcile the problem of pain with a providential God does not mean it cannot be done. Pain has been the subject of religious debate for the entire history of Christianity, and Kitcher’s summary rejection of a providential God based on the problem of pain is a testament to his lack of scholarship.

Living With Darwin offers a nice treatment of the history of objections to Darwinism, but it is marred by Kitcher’s superficial and trite philosophy.


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