Granted, my twitter feed is a mess. I get a disparate line of sludge all day long on my tweet-deck: stock traders bemoaning Bernanke, short-sellers calling for the next crash, White Sox fans wondering why the Twins keep winning (I know that answer: no walks, no errors), Republicans still obsessed with Obama's nation of birth... but yesterday's favorite-- if only because I haven't seen this theme in a week or more-- is yet another Final Refutation of Darwin, sort of.
I'm not picking on this particular Twitterer, well maybe a little, but if we're going engage in pseudo-intellectual repartee, then I think this tweet deserves a deeper dissection. In two short lines I find nearly everything wrong with today's popular culture. We say things like "evidence", yet very likely we have not personally reviewed the said evidence; this is beyond lack of rigor, this is lack of reading. Because it one were to read even the abstract of the "evidence" in question, one would learn immediately that not only is there no challenge to Darwin's theory extant in the study, but rather the study supports Darwin's long-standing thesis that individuals within taxa compete for habitat as part of the process of natural selection. It doesn't take a scientist to discern the implication of the "evidence." To wit, Sarda Sahney, et al, from Biology Letters states in the abstract:
"Tetrapod biodiversity today is great; over the past 400 Myr since vertebrates moved onto land, global tetrapod diversity has risen exponentially, punctuated by losses during major extinctions. There are links between the total global diversity of tetrapods and the diversity of their ecological roles, yet no one fully understands the interplay of these two aspects of biodiversity and a numerical analysis of this relationship has not so far been undertaken. Here we show that the global taxonomic and ecological diversity of tetrapods are closely linked. Throughout geological time, patterns of global diversity of tetrapod families show 97 per cent correlation with ecological modes. Global taxonomic and ecological diversity of this group correlates closely with the dominant classes of tetrapods (amphibians in the Palaeozoic, reptiles in the Mesozoic, birds and mammals in the Cenozoic). These groups have driven ecological diversity by expansion and contraction of occupied ecospace, rather than by direct competition within existing ecospace and each group has used ecospace at a greater rate than their predecessors." [italics mine-Tony]
In other words, the tetrapod populations have taken advantage of ecospace by expanding the boundaries of the habitat which they occupy. That's Darwinism! They expand their habitat by adapting to a larger part of their ecospace, which then improves their reproductive capability, yada, yada, yada.
In fact, the author, Sahney, has stated definitively, "We are not in any way suggesting Darwin was wrong," and Steven Newton, (in the same reference) explains:
"But we can also understand this idea with an analogy to a more familiar topic: Darwin's famous Galápagos finches. These birds occupy small, parched islands, on which perennial drought severely limits vegetation. This creates a situation of scarcity in which even small differences in beaks may confer significant advantages... Now imagine that a new volcanic island erupts in the Galápagos chain. Suddenly an expanse of new, un-colonized land is available; new food sources will grow there. How will this new land affect finch diversification? That's the kind of question being addressed here."
Okay, so the science in this study is consistent with Darwin's theory of the origin of species through natural selection, a theory which is so exceedingly elegant that it is consistent with the last 150 years of empiric evidence in archeology, geology, comparative anatomy, and all accumulated findings within the sciences of biochemistry, molecular biology and genetics. Quite a daunting body of support to be cast asunder by one grad student's study of habitat, no?
Why did twitterdom get all a-twitter over the misinterpretation of the study? Perhaps because multiple sources, and especially the BBC science writer (the same one who says "birds learned how to fly"-- they didn't, dinosaurs flew and then evolved into birds, but whatever), mis-characterized the paper as some sort of refutation of Darwin, with the opening line: "Charles Darwin may have been wrong when he argued that competition was the major driving force of evolution." Of course, this inane statement could be also be due to the co-author Prof Mike Benton who is quoted as saying:
"...competition did not play a big role in the overall pattern of evolution. For example, even though mammals lived beside dinosaurs for 60 million years, they were not able to out-compete the dominant reptiles. But when the dinosaurs went extinct, mammals quickly filled the empty niches they left and today mammals dominate the land." [emphasis mine-Tony]
According to the Darwin model, competition still occurred within the habitat utilized. Notice Benton did not say competition had no role, he is only remarking on the relative importance of competition depending on various factors, such as availability of habitat. Sure, his statement could be more clear, but such is the world of the three-line sound bite. No matter, an American professor sets the record straight later in the same article:
But there was always wicked competition within the ecospace and as Professor Stephen Stearns, an evolutionary biologist at Yale University, US, told BBC News he "found the patterns interesting, but the interpretation problematic".
He explained: "To give one example, if the reptiles had not been competitively superior to the mammals during the Mesozoic (era), then why did the mammals only expand after the large reptiles went extinct at the end of the Mesozoic?"
"And in general, what is the impetus to occupy new portions of ecological space if not to avoid competition with the species in the space already occupied?"
Indeed.
The next part of the tweet in question is a quote from an alleged authority, Fr Robert Spitzer, that this challenge to Darwin "could be valid." Ah, the wonderful world of could, a conditional auxiliary which absolves the user of all responsibility of proof, or even rational conjecture. The Kalamazoo Post "could be" the premier blog on the internet! Or not. We'll never know, will we? The possibility certainly exists. Why? Because the possibilities of "could" are endless in the endless world of twitterdom.
So now we need to dissect the argument of Father Robert Spitzer, the Jesuit president of Gonzaga University, to see if he is indeed casting aspersions on the venerable Darwin. Spitzer states:
“For all intents and purposes then, the argument that space may have driven the development of species or one species' dominance over the other could be very much valid and, frankly, just as valid as competition. Both theories could be valid,” he stated, adding that the development of species could also have been driven “by another explanation that we don't yet know of.” [italics mine-Tony]
Close, but no cigar. Yes, both theories could be valid, or more exactly, both theses are indeed a valid part of the overall Theory of Evolution, which states categorically that speciation emanates from individuals competing for habitat (space, food and safety from predators.) Competition and space are both included within the grand theory, but they are not mutually exclusive. But what's with the stuff about "another explanation that we don't yet know of"? What did he have in mind?
Of course, to earn his priestly collar, the erudite sectarian scholar must pretend that there is some doubt about the validity of the Great Darwin as the jackals descend on his dying theory, and Spitzer reminds us that it still cannot be known absolutely if natural selection is the only model that can abide speciation. Yes, another explanation can be entertained! Of course, we should always keep the option open that speciation may have occurred by some as yet unknown force, but what is it? No conjecture? Maybe Noahs' Ark may still be found on Mt Ararat.
Perhaps I should show more reverence for the Reverend, after all he did couch his statement in all kinds of political mumbo jumbo so he is technically correct, but this is the kind of tortured logic that shows the utter silliness of religious arguments concerning science. If you want to refute Darwin, or intimate that his theory is flawed, then say so up front, and come up with a model to replace it that would better fulfill all the necessary criteria. Say it's the magic sky wizard that created species, or spontaneous mutation from extraterrestrial DNA, or something... but ple-e-e-ese don't fill my computer screen with malarkey about evidence that "could be valid" when there is no evidence, the authors say there is no evidence, you likely didn't read the study or even the entire BBC news article past the lede*, and there has never been any scientific evidence that has been inconsistent with Darwin's theory (which is actually the most amazing thing about this sordid tweet affair.)
The fact is that science has been eating religion's lunch for the better part of 500 years. Every generation has been marked by revealed religion surrendering ground to the army of scientists who have methodically revealed our existence in terms of chemical and physical properties that have left supernatural dogma crippled and dead. The priests are left to talk about the after-life and intercessionary prayer and "evidence that could be valid" since all else has shown them to be in error, and they have learned to qualify all their statements with conditional phrases, and then they lash out from their darkness when they smell blood, and pray it's Darwin's-- but it's only their own.
If only they could take down Darwin! The trumpets would blare! Hosannas would ring out! Jeebus would come back on a cloud to stuff Darwin down the puke funnel once and for all!
I realize that the nature of Twitter is to mimic stream of consciousness, which can be an attribute and a curse. The attribute is that we get inundated with a zillion themes and stories that might pique our interest. The curse is that we might read only the headline, or the "authority's" sound-bite and get the entire story wrong. Caveat Twitdor. Let the Twitterer beware.
*Fr. Spitzer was on Larry King tonight with Deepak Chopra, Leonard Mlodinow and Stephen Hawking, and the pious university president argued with the latter two about their new book while it was clear Spitzer had not even read the book!
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