Textbooks often don’t discuss extinction – the death of all members of a species – in any detail. No surprise there, it’s a frustrating and depressing topic.
Frustrating because museums would bid billions to bring back a live tyrannosaur. And depressing because good answers are often not available. So discussion can lurch dangerously into the realm of folklore.
When that happens, folklore wins hands down over fact. The extinction of the entire superorder of dinosaurs  which marked the close of the Cretaceous era – perhaps mainly due to an asteroid hit – has become a pop culture icon that now supports a variety of views and causes.
Pop culture need not – and does not – address the real history of life. For example, the extinction of all species of trilobite, the signature fossil of the Cambrian era, goes largely unnoticed simply because trilobites never became a pop culture icon. In any event, when discussing extinctions, competent and honest scientists can reach different conclusions.  But understanding the history of life requires that we grapple with what we do know about natural* extinctions, as well as about the actual patterns of evolution and of stasis (vast periods in which nothing much happens to a life form).
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Raup ends his 1991 book on a curious note, attributing to Darwin’s theory of evolution powers he does not actually discuss in his own book – yet he then reserves a key judgment:
“Is extinction through bad luck a challenge to Darwin’s natural selection? No. Natural selection remains the only viable, naturalistic explanation we have for sophisticated adaptations like eyes and wings. We would not be here without natural selection. Extinction by bad luck merely adds another element to the evolutionary process, operating at the level species, families, and classes, rather than the level of local breeding populations of single species. Thus, Darwinism is alive and well, but, I submit, it cannot have operated by itself to produce the diversity of life today.”
– David M. Raup, Extinction: Bad Genes or Bad Luck? (New York: W.W. Norton & Company, 1991), p. 192.
Interesting! What does he think “Darwin’s natural selection” cannot have done? Compare this with what he says in the quotation just above [in the linked article], about the Pleistocene rain forests.
In his day, Raup was taking a big risk by even suggesting that Darwinism might not be true, so he wisely merely provides facts that dispute it – and then covers his tracks with a resounding promotion of Darwinism in areas of study that he does not actually address in his book in any detail.
Sometimes, that is the only way to get key information across.
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2 Replies to “Design of Life: Extinction – and so, good night, the final curtain …”
I have a question relating to extinction. I have read an article reporting that Christopher Hitchens, in his debate with Jay Richards, refused to accept the evidence for design in nature, on the grounds that a Designer would not create different kinds of organisms, only to watch them become extinct, which is what has happened to more than 99% of all the species that have ever lived. Hitchens IS making an assumption here: from the premise that God does nothing in vain, it does not necessarily follow that God would never allow His own handiwork to be destroyed. Nevertheless, the assumption is a plausible one: designers do not normally like seeing their handiwork destroyed.
Where Hitchens goes wrong, I would suggest, is in identifying God’s “handiwork” with the various kinds of CREATURES that have lived on Earth during the past 4 billion years, instead of identifying it with the irreducibly complex STRUCTURES that God has designed.
Once we recognize this point, we can now clarify the theological issue at stake here. If God does not like to see His handiwork destroyed, then we should expect irreducibly complex STRUCTURES (not SPECIES) to endure over time, once they have been created.
So my question is: does anyone know of an irreducibly complex structure that once existed in the natural world, and does not now exist? If there is one, then Hitchens has indeed scored a rhetorical point.
The trilobite eye might spring to mind for some readers, but this would be an invalid example, in my opinion, as it does not appear to have any IRREDUCIBLY COMPLEX features that distinguish it from the other kinds of eyes that can be found in the animal kingdom. Presumably, if God designed the eye, then He did so by designing the genes that code for eyes in the various animal lineages, long before they diverged from one another.
Can anyone think of any other intelligently designed structures that have disappeared from nature?
Nearly all the arguments for one’s point of view on evolution is negative. We destroy the other’s arguments with negative information about their position to support our own position. The theodicy argument and the imperfect design argument are the cornerstone for denying an intelligent input especially one from the Judeo Christian God.
The attack on naturalistic basis for evolution is based on the negative evidence for Darwinian processes. Namely, there isn’t any positive evidence for gradualism but wild speculations. So those who doubt Darwinian processes use essentially negative information and not positive information for another process.
We arrive at intelligent inputs to evolution by default. Namely, there is no evidence for a naturalistic process to produce the results we see in life’s progression.
However, we also gloss over the inconsistencies that exist by postulating an intelligent designer popping in an out of the environment every so many millions of years to effect a change in life’s course.
I personally don’t find any big deal with extinction. If there is a plan for life to lead to humans and somehow it needed 4.5 billion years then a lot of adjustments had to be made along the way including extinctions. We no longer use a lot of things that our ancestors thought essential. In chess it is necessary sometimes to sacrifice the queen in order to achieve success. So loss of previous intelligently designed elements is no big deal.
However, what intelligence is necessary to monitor a situation for all this time and then make the adjustments when necessary. These are all questions that do not get discussed that thoroughly and strike at the heart of the ID discussion.
There are a lot of inconsistencies in this debate. And we may never be able to answer them. When I was growing up I was taught there were a lot of mysteries in life that we would probably never solve. While science can consistently add to our understanding there are some mysteries that are beyond science.