The title of the article at issue is a masterpiece of dissimulation, because if you read the piece you’ll find that its author, a rabbi, is skeptical completely because of religion. In fact, I’ve known of only one evolution-denier who didn’t form that opinion on religious grounds (it’s David Berlinski, and I suspect he’s a secret believer), although I suppose there’s a smattering of others.
Anyway, the title of the piece, published at the Jewish website Tablet, is “Skeptical about evolution—and not because of religion“, and it’s by Avi Shafran, a New York rabbi with his own website.
Why the skepticism? Well, Shafran first cites a new study in Current Biology showing that the rate of “radiation” (formation of new species) in mammals, along with the pace of morphological change during that radiation, was much higher in the middle to late Jurassic than previously suspected. Here’s part of that paper’s abstract:
We assess rates of morphological evolution and temporal patterns of disparity using large datasets of discrete characters. Rates of morphological evolution were significantly elevated prior to the Late Jurassic, with a pronounced peak occurring during the Early to Middle Jurassic. This intense burst of phenotypic innovation coincided with a stepwise increase in apparent long-term standing diversity [ 4 ] and the attainment of maximum disparity, supporting a “short-fuse” model of early mammalian diversification [ 2, 3 ]. Rates then declined sharply, and remained significantly low until the end of the Mesozoic, even among therians. This supports the “long-fuse” model of diversification in Mesozoic therians.
This is no big deal: we have plenty of examples of the pace of evolutionary change varying greatly over time, for the strength of natural selection, which promotes much of that change, surely changes over time, as when the climate suddenly varies or new ecological niches become open. This is not news. It’s not as if a whole group of mammals suddenly appeared, as if God created them ex nihilo. It’s simply variation in rates!
Rabbi Shafran, however, seems to think that this casts serious doubt on evolution:
A relatively minor discovery but it wasn’t expected. In fact, larger surprises, leading to substantive revisions in the study of evolution are the rule rather than the exception. From Lamarckism to classical natural selection to Darwinism to the Modern Synthesis, evolution theory, well, evolves. But whatever mechanisms are believed to serve as the engine of evolution, the theory’s fundamental idea remains that life sprang from inanimate matter and came to yield all the organisms in the biosphere we occupy. As such, the news was, for me, another opportunity to come face-to-face with a personal reality.
Seriously, a variation in evolutionary rates creates a “substantive revision in the study of evolution”? Not in my view, for even Darwin, in The Origin, points out the likelihood of rate variation. It would in fact be surprising if such variation didn’t occur; it’s precisely what’s expected under natural selection. When selection is very strong, as in artificial selection practiced by human to create dog breeds, we can get tremendous morphological variation in only 10,000 years: dog breeds would be recognized as different species, if not different genera, if they were found only as fossilized skeletons.
It turns out, though, that Shafran’s Big Beef isn’t this rate variation, it’s the fact that he doesn’t think that evolution has been sufficient to explain a.) the proliferation of species over the history of life, and b.) the origin of life itself.
. . . Instead, I refer to a real heresy: my reluctance to accept an orthodoxy so deeply entrenched in contemporary society that its rejection summons a heavy hail of derision and ridicule, and results in effective excommunication from polite society. What I can’t bring myself to maintain belief in is… evolution.
I don’t reject science, only speculations and assumptions made in its name. . .
. . . What I cannot bring myself to accept, though, is speciation, the notion that the approximately 10 million distinct species on earth (along with another estimated 20 million marine microbial organisms) all developed from a common ancestor.
So he doubts common ancestry, the result of the branching process of speciation.
Has life proliferated too fast to be explained by natural processes? No. Let’s assume that we start with one species 3.5 billion years ago (the “universal common ancestor”, or UCA), and it simply bifurcates into two lineages. How long would it take to get to a billion species? (The rabbi estimates ten million today, but let’s assume, as is reasonable that 99% of the species formed since the UCA went extinct without leaving descendants. So we have to account for the evolution of a billion species) That’s an easy calculation (watch; I’ll screw it up!):
2^x = 1,000,000,000, where x is the number of splitting events required to produce a billion species.
x log 2 = log 1,000,000,000 = 9
x = 9/0.301 ≈ 30
In other words, only 30 splitting events would yield that billion species. Over 3.5 billon years, that’s one speciation event every 116 million years. As Allen Orr and I calculated in our book Speciation, on average a new species forms by splitting of a given lineage at a rate between one every 100,000 years and one every million years. (This is a rough estimate, of course, and varies by taxa.) The upshot: the data we have on species formation shows that there’s been plenty of time time for evolution to have created a billion or even 100 billon species.
But the data is stronger than that, for we have tons of evidence showing the common ancestry of those species. For some reason—and I hope it’s not willful ignorance—Rabbi Shafran neglects that evidence.
These data include the presence of predicted transitional forms between extant groups (e.g., fish and amphibians, like Tiktaalik, amphibians and reptiles, reptiles and mammals, reptiles and birds, early apes to our own species, and so on). The data include the hierarchical distribution of genes and traits, as predicted by a branching process. The data include the distribution of species on the surface of the planet— biogeography—showing species forming from other species. And the data include the location of specific junk DNA, like transposable elements, residing in the exact same position in the DNA of species descended from common ancestors, like humans and chimps. We also have seen speciation in action in many organisms, especially in the formation of polyploid plants (see Speciation), which constitute a sizeable percentage of existing plant species that have formed naturally.
So Rabbi Shafran seems to be ignorant of the massive data supporting speciation. He prefers instead to rely on rabbis rather than scientists. Here’s where his claim that his motivation is not religious become a clear lie:
I claim no official scientific credentials, but have had an abiding interest in science since I was a boy (which, as noted, was a good while back). As a young man, I devoured the layman-friendly but well-informed works of Asimov, Gould, Dawkins, Thomas and others, never doubting the assumption that speciation was fact. Until I decided to apply my own critical thinking to the theory’s assumptions. My faculties, I know, are puny compared to those scientists’. But I can’t help but feel that while brilliant people may always be brilliant, they can also sometimes be wrong.
While I believe in the divine origin of the Torah and its account of creation [JAC: if he is going by evidence, as he claims, he’d completely reject the divine origin of the Torah], my refusal to accept speciation as fact is based on reason, not religion. In fact, contrary to popular perception of religious thought, not believing in evolution is hardly dogma: no less an Orthodox luminary than the illustrious 19th century thinker Rabbi Samson Raphael Hirsch allowed for the possibility that all life might come from a single simple organism.
. . . But, to my lights, that “vague hypothesis,” as Rabbi Hirsch characterized it, remains just that, more than a century later. When scientists in a lab manage to create a living organism (let alone a reproducing one) from inanimate matter, or to irradiate a simple organism and turn it into a clearly different one, I will happily concede the possibility, at least, that such happened in the past. That it happened millions of times? Well, we’ll talk.
I fully appreciate the fossil record and the similarities among some different species. And I realize that organisms have been bred or mutated in ways that, using arbitrary definitions, are called “new” species. But a fruit fly has never been coaxed into becoming a housefly. [JAC: Ah, here we see the creationist canard that “if you can’t see a new species form, it didn’t happen.” The good Rabbi doesn’t appreciate the value of historical reconstruction as an accepted part of science.]
. . . In the meanwhile, lead me to the stocks, if you must. And as I’m pilloried, I will proclaim the words of a famous man who once wrote that “it is always advisable,” when dealing with things beyond our immediate experience, “to perceive clearly our ignorance.”
His name was Charles Darwin.
Yes, but the Rabbi neglects to add Darwin adduced evidence for his ideas, and much of that evidence was either indirect (as in biogeography), or historical, but in the end the inferences were TESTABLE. Darwin had no fossil record to support his ideas, nor did he have any evidence of speciation or evolution occurring in real time—except under artificial selection. Despite that, the evidence that has mounted since 1859 shows that Darwin’s theory, including splitting of lineages, has become fact. It is accepted by all rational people and the huge majority of scientist (engineers and dentists don’t count.) Those who reject it are either ignorant of the evidence or, in the case of Shafran, blinded to the evidence by their adherence to Yahweh.
I don’t have to lead Rabbi Shafran to the stocks: he’s voluntarily put himself there! There’s no need to pelt him with rotten tomatoes and eggs, either, as he’s put the egg on his face all by himself.
h/t: Michael
