Wednesday, May 21, 2014

it's called "natural selection" for a reason

evolutionary biologist jerry coyne @ whyevolutionistrue:

one reader wanted to know if i was going ask [dr. eugenie scott, former head of the national center for science education (NCSE) and known as "genie" to everyone] about theistic evolution — the view that evolution happened, but was somehow guided by god. they wanted to know if she considered that "real" evolution.

i responded on this site that i hardly wanted to get into a kerfuffle about the issue with genie in public. after all, i know her position on it (theistic evolution is okay), she knows mine, and i didn't want to do battle in public, particularly when she was giving a keynote talk.

but this website is a different matter.

in fact, the question of theistic evolution did come up in genie's Q&A, when one of the audience asked genie whether she considered theistic evolution "science."

the question clearly discomfited her a bit, but i knew how she would answer. she said, correctly, that there are a huge variety of positions falling under "theistic evolution," ranging from pure deism (god created the universe, and then evolution proceeded purely naturalistically) to other forms in which god intervened to a greater or lesser extent. as we know, those interventions range from subtle ones (god tweaked certain mutations making it more likely that they would be more likely to be adaptive, or more likely to create human features), to less subtle (god inserted a soul in the human lineage) to pretty drastic interventions (god let some species evolve naturally, but brought others into existence ex nihilo).

theistic evolution is in fact the most widely accepted form of evolution in america, at least for the evolution of our species. a gallup poll in 2012 showed that 46% of americans thought god created humans ex nihilo within the last 10,000 years, 32% thought that humans evolved, but with the help of god, and only 15% thought that humans evolved without any intervention by god. in other words, roughly one in seven american accepts evolution in the same way scientists do. for every american who accepts naturalistic evolution, more than two accept god-guided evolution. (i think accepting that "god guided the process" rules out pure deism.)

genie said something like this (i didn't write down her words), "what we care about is getting the science accepted, and yes, all of these positions are compatible with science, so i have no problem considering them as science." in other words, she'd be okay if she or the NCSE could simply make religious people accept theistic evolution. for, in her view, they'd be accepting a scientific view rather than a religious one. and then they might be our allies in keeping straight creationism out of public schools.

and here i think genie is wrong — dead wrong.

theistic evolution is neither science nor scientific. while it may help some religious people oppose the teaching of strict creationism in schools (the real goal of the NCSE's accommodationism), it inculcates people with the idea that god and his supernatural acts can work hand-in-hand with physical laws to bring about a process that scientists think is purely naturalistic.

further, we have evidence against certain types of theistic evolution. there doesn't appear to be any telelogical forces driving evolution in a certain direction; there is no evidence that mutations are more likely to be useful when the environment changes, so that mutations for longer fur in mammals would occur more frequently when the climate becomes colder (this is what scientists mean when we say that "mutations are random", although "indifferent" is a better word than "random"); and we don't see violations of darwinian natural selection, that is, we don't see natural selection creating "irreducible complexity," as intelligent-design advocates maintain.

as far as we can see, then, evolution, like all things that occur in nature, is purely naturalistic; it does not require or give evidence for the intervention of a god. as laplace famously said, "we don't need that hypothesis." theistic evolution says otherwise. and that's unscientific. there is, after all, a reason that darwin called his best idea natural selection, not "divinely-aided selection."

think about it. saying that theistic evolution is scientific is equivalent to saying that yes, chemical bonds form between sodium and chloride ions, but those bonds are formed with the help of god. why not have theistic chemistry? or that the universe is expanding, but god is helping it expand. why not have theistic cosmology?

those hypotheses are unscientific because they not only posit an intervention that isn't observed, but invoke a superfluous and supernatural intervention to explain a process that can be explained adequately using pure naturalism. god is a useless "add-on" here, and that's not the way science works. science works best when we make theories that assume no more than we need to. while it's logically possible for god to be guiding particles and directing evolution, we have no evidence that this is true. theistic evolution is not required by science; it is, as we must admit, simply something tacked on to make religious people feel better about a process that, if purely naturalistic, is taken as a direct attack on their worldview.

further, theistic evolution is, to use genie's own term, a "science stopper." if you say that god is making mutations, or expanding the universe, then we need investigate no further. what we don't understand can simply be fobbed off on the will of a divine being. there's need to look for that elusive naturalistic explanation.

the tactic of considering theistic evolution as "scientific" is a purely political one. the NCSE and others (viz., the american association for the advancement of science and the national academy of sciences), feel that to get evolution accepted and taught in schools, we need religious allies. and to get those allies, we have to accept their view that evolution was guided by god, even though we don't believe it ourselves.

science makes progress only when it doesn't evoke a god. even the NCSE accepts that "methodological naturalism" — the rejection of divine hypotheses — is the way that science has progressed. so why reject god when you're doing science, but then admit on the sly that he might be in there working away subtly and, perhaps, undetectably? that is a political view, not a scientific one, and it dilutes and pollutes the scientific enterprise. it also gives the public the false idea that theistic evolution is somehow okay with scientists.

it isn't. no evolutionary biologist puts in her scientific papers a note to the effect that god might be involved in the process she's studying. anyone doing that would be laughed out of the field. so if scientists reject theistic evolution in their own work, why accept it when the public believes it? it's pure hypocrisy to do so, and a blatant attempt to coddle believers.

i'd rather stand up for the purity and naturalism of science than accept forms of science that invoke god. yes, i'll be glad to work with religious people to help expel creationism from schools — and theistic evolution is a form of creationism!. what i won't do is give my imprimatur to a form of evolution that includes the supernatural. until we have some evidence for the supernatural in science — and we certainly don't at this point — let's not grant it simply to gain allies. that is a false alliance that, in the end, creates a public misunderstanding of science.

it is ironic that the national center for science education is willing to include theistic evolution as "scientific." it is wrong, it is hypocritical, and it's a cynical political tactic unbecoming to scientists. the NCSE has done terrific work in keeping creationism out of schools. but in saying that theistic evolution is "scientific," as genie did on sunday, we are shooting ourselves in the foot. what is science profited if we help evolution get accepted more widely, but in so doing lose our own scientific soul?

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