Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
If I could change places with anyone in history, I’d be strongly tempted to choose Winston Churchill, if for no other reason that he made such a huge difference in winning WWII. (Readers: feel free to name who you’d change places with.)
The finest biography of Churchill that I’ve read—indeed, the best biography of any sort I’ve ever read—is William Manchester’s two-volume classic The Last Lion. It was a great tragedy, and really frustrating, that Manchester died before producing the last and most exciting volume: Manchester’s narrative ends right as Churchill became Prime Minister in 1940.
But Churchill lovers rejoice—the lacuna is filled. The latest New York Review of Books (via reviewer Brian Urquart) gives huge encomiums to Max Hastings’s new biography:
Hastings’s Winston’s War: Churchill, 1940–1945 is a magnificent achievement. After the vast number of works on Churchill that have appeared in the last sixty-five years, one could be forgiven for thinking that everything significant must already have been said, but Winston’s War is something fresh and different. Churchill’s inspired leadership and the unique strength of his will saved Britain from defeat and occupation and did much to make the ultimately victorious alliance possible. Hastings’s wealth of research, quotation, anecdote, and comment builds up a living picture of the genius, as well as of the heroic flaws, of this immensely gifted and fascinating human being.
I heard Hastings give a nice talk on this book at the Hay Festival, and I’ll be getting it for sure. (Amazon’s asking $23 for the hardback.)
After Jerry Fodor and Massimo Piattelli-Palmarini took a severe drubbing for their book, What Darwin Got Wrong—a drubbing, I might add, from both philosophers and biologists—you might expect that they’d rethink their ideas. But this presumes that you don’t know Fodor, who’s renowned for both his arrogance and his inability to admit error. Over at the Simply Darwin website, Fodor doesn’t back off an inch from his claim that natural selection is not only wrong, but doesn’t even exist. He thinks, apparently, that history will vindicate him:
Q: Has your viewpoint changed or evolved, in light of the criticism it has received for your earlier expressions of it, now that it has been more fully developed in your new book “What Darwin Got Wrong?”
A: No. The criticisms I’ve seen have been mostly fatuous; a substantial minority haven’t even managed to get straight on what my argument is supposed to be; in particular, on why the intensionality of ‘select-for’ plays such a central role in it. But I suppose things will catch up sooner or later. I’m not in a rush. . .
. . . Q: If adaptationism fails, as you argue, to tell the whole story, then what would you suggest take its place?
A: My guess is that there isn’t any such thing as a (general) theory of evolution (just as, it turns out in Skinner’s case, that there is no such thing as a general theory of learning.) Skinner and Darwin both made bad bets on what would prove to be natural kinds: Learning in Skinner’s case, trait fixation in Darwin’s. I expect that natural history is about as close as you can get to an empirical account of trait fixation; and it’s more or less common ground that natural history takes things case by case and offers only explanations that are ad hoc and post hoc (as, indeed, does every other kind of historical explanation). I know that, for some reason, some biologists find this suggestion demeaning. Well, as Lewontin said in respect of a related issue: ‘Tough!’
Here Fodor completely ignores all the examples given by critics (including me) showing that selectionist explanations are not ad hoc and post hoc rationalizations, but can be tested (e.g. predation experiments in peppered moths and white vs. brown mice [see the latest issue of Evolution]). Here, at least, you think he’d stand corrected. But no way:
Q: In the weeks since your book was released, it has been vehemently attacked from many quarters. From what you’ve read so far, what do you take to be the main point of divergence that these criticisms have taken against your stance?
A: I doubt that there is a main point; just a lot of misreading and flawed dialectic together with a substantial dollop of hysteria.
Fodor was once a respected and a daunting philosopher. His battles with Dan Dennett about consciousness and cognition were epic—and enlightening. But he (and Piattelli-Palmarini) have gone into the dumpster with this Darwin business. Sad to say, the latter-day Fodor is silly, stupid, and supercilious. We’ll hear no more about him on this website.
Here’s our sophisticated theology of the week, an explanation of why the deity runs his creation using random processes, like mutation or the chance fertilization of an egg by a sperm, instead of direct intervention:
Why does God use processes many of which involve non-determinacy rather than direct action? We don’t know for certain, but some plausible answers have been suggested:
First, let’s consider the question of why God uses secondary agents rather than direct action. The Genesis account of human creation says that God placed the man and woman in the garden to tend and care for it. This passage is often seen as revealing God’s plan that human beings should serve as his stewards of the earth. By establishing processes rather than using direct action, God has made a stable, understandable world that humans are able to steward.
Second, let’s look at why such processes include non-determinacy. One plausible answer is that it is simply good management practice. Good managers don’t micromanage; rather they focus on the big picture and leave the details to subordinates. Thus non-determinacy provides a highly effective process for generating and maintaining stable ecosystems and life itself without direct control on God’s part, when direct control would mean constantly managing every aspect of billions of billions of billions of molecules. Another plausible explanation for non-determinacy is that God lovingly gives freedom and/or agency to creatures. We might say the Creator creates creatures that join in the creative process. Genesis 1 seems to support this view, for Scripture several times says God that commands creatures to “bring forth” other creatures.
Going through the July 13 issue of Current Biology, I was struck by just how many interesting things you can learn from a single issue of a journal:
From a review of the new book Butterflies: Messages from Psyche, by Philip Howse: The Atlas moth (Attacus atlas) evolved the image of a snake head at the tip of each wing; the moth flicks its wings when disturbed to mimic a snake’s swaying motion.
Atlas moth (Photo: copyright Stratford upon Avon Butterfly Farm Ltd.)
The eyed hawk moth (Smerinthus ocellata) has wing patterns that look like the face of a fox. Could this be aggressive mimicry of a mammal, evolved to frighten predators?
Eyed hawk moth (Photo: copyright Chris Manley)
Fungus-growing ants use bacteria (which produce antibiotics) to keep down the parasites in their fungus gardens. The ants also exhibit “proactive hygiene,” grooming themselves compulsively before entering the garden chamber of the nest. They groom themselves longer if they’re more contaminated by microbes, but don’t groom when there is no fungus growing in the garden.
Adult mongooses crack bird eggs by either biting them or throwing them against rocks. Some scientists made artificial eggs and watched how adults opened them while juveniles were nearby. Two to four months later, the juveniles were presented with fake eggs. Surprisingly, they used whichever opening method—either biting or throwing—that they had witnessed much earlier. According to the authors, this is the first evidence in any animal for “social learning involved in the transmission of behavioral variants between individuals.” I don’t know enough about things like primate behavior to judge if this is true.
An artificial egg for the mongooses.
Cleaner fish, who remove parasites from other “client” fish (thereby getting a meal) in a famous example of mutualism, have evolved independently many times. One species (L. dimidatus) eats 1200 parasites per day, most of them isopods. When fish are caged and not allowed access to cleaners, the isopods can increase more than fourfold on the fish’s body in 12 hours, and can kill it. But who cleans the cleaner fish? Answer: they clean each other.
The bluestreak cleaner wrasse, Labroides dimidiatus (left) cleaning a “client,”a Pacific sailfin tang (Zebrasoma veliferum). Photo (in the journal) by Karen Cheney
This is relevant to our discussion of senescence. In an intruigingly-named dispatch called “Behavioral ecology: the menopausal aphid glue-bomb” (who wouldn’t read a dispatch with a title like that?), William Foster highlights some nice work—published in the same issue—by Keigo Uematsu and colleagues from the University of Tokyo. The gall-forming aphid Quadrartu yoshinomiya is clonal: females produce exact genetic copies of themselves via parthenogenesis. (Galls are bizarre growths on plants that are induced by insects themselves; the evolution of gall making is another fascinating evolutionary tale.) The aphids have an unusually long life span, hanging around well after they stop reproducing. It turns out that post-reproductive (“menopausal”) aphids cluster around the opening of the gall (through which the aphids exit), and secrete a glue when a predator (e.g., a ladybug) is nearby. This glue gums up both the aphid and the predator, dooming both to death. The authors do a bunch of experiments supporting their idea that this “altruistic” behavior, which really does keep down predators, has evolved via kin selection. The aphids are, after all, clonal, so when an individual dies as a glue bomb, it’s really helping save exact copies of its genome. This is analogous to sterile worker bees dying after they sting an enemy (the sting pulls out the worker’s innards), thereby saving their future-queen sisters, with whom they share three-quarters of their genes.
Aphid gall on evergreen witch-hazel (Distylium racemosus). The meonopausal glue-bomb aphids are clustered around the gall entrance, waiting to bomb predators. Photo by Harunobu Shibao.
C. Wingless adult aphids secreting glue (scale: 0.5 mm). D. Wingless adults (arrows) stuck with glue to a doomed predatory ladybug larva.
These are only about half of the articles/dispatches I read in this issue, and this is but single issue of a single journal—there are dozens of journals relevant to evolutionary biology. And this is why it’s so much fun to be a biologist. Not only do we get to find out stuff in our own labs, but we get to read about all the cool stuff that other people have found out. In other words, every day we go to work expecting to learn about new marvels of nature. And those marvels are, apparently, inexhaustible. Imagine getting paid to do this!
Now many of these articles are also of interest to laypeople who are curious about science, but how many laypeople read scientific journals? Most of those journals are expensive, arcane, and can’t be seen online for free. I can’t do posts like this every day, so if you’re a parent, and want your kids to have as much fun as we do, by all means expose them to biology when they’re young.
Oh, and congratulations to Geoff North and his team at Current Biology for keeping the journal a repository of not only good science, but good stories as well.
________
p.s. The latest (July 27) issue of Current Biology contains a nice “quick guide” to pycnogonids, or sea spiders, by our own pinch-blogger Matthew Cobb. Pycnogonids are bizarre marine arthropods that appear to be all legs and no body:
The pycnogonid Colossendeis gigas perched on an anemone, Liponema brevicornis, 2893 meters down in Monterey Submarine Canyon, CA, USA. Photo (c) 2005 MBARI.
I must be doing something right: twice in one week Sauron has ordered his minions from BioLogos to call me out on HuffPo.
Pete Enns, BioLogos’s senior fellow in Biblical studies, takes exception to the polling data I cited showing that many Americans are not only creationists, but see the Bible as the precise word of God. Enns notes that these polling questions were ambiguously worded, making their interpretation dicey. Ergo Jesus. Well, I’ll grant that in some polls the questions could be misleading. Nevertheless, all polls, with their diverse ways of posing the question, show that about 40% of American are Biblical creationists. And perhaps Enns could tell us what’s so misleading about the poll questions showing that 81% of Americans believe in heaven, 78% in angels, 70% in Satan, and 70% in hell. Maybe they interpret the question as actually asking about a metaphorical hell (e.g., spending your days reconciling science with the story of Adam and Eve).
BioLogos‘s vice president, Karl Giberson, whom I recently debated about the compatibility of science and faith (video pending), engages in classic displacement behavior: he argues that one analogy I used is weak. The analogy at issue: “Catholicism is compatible with pedophilia because many Catholics are pedophiles.” This was meant to show that compatibility isn’t demonstrated simply by people holding two contradictory views in their heads. (Along with many accommodationists, Giberson seems to believe that the existence of religious scientists is evidence for the compatibility of science and faith.)
According to Giberson, this analogy doesn’t work because those child-abusing priests know that it is wrong. They have cognitive dissonance. In contrast, the religious scientist has no such dissonance:
A religious scientist functions routinely as a scientist in the lab, perhaps looking for the gene that causes hyperbole. While they [sic] are engaged in this search they believe that God is the creator. On regular occasions this scientist goes to church, where he or she sings hymns, listens to sermons, volunteers at the soup kitchen, takes communion, and puts money in the offering plate, all the while believing that the scientific picture of the world is accurate. Occasionally this religious scientist may even daydream about finding that gene for hyperbole while listening to the sermon. At no time do the co-existing mindsets conflict or create cognitive dissonance.
QED: science and faith are compatible.
Never mind that some pedophilic priests almost certainly aren’t tortured by guilt, or that any dissonance might come from the fear of detection rather than genuine guilt. Never mind that monogamous adulterers may live a happy and unconflicted life with their duplicity (indeed, I’ve known some!). There are many forms of hypocrisy, and not all hypocrites are tortured. I would add that a lot of people who try to adhere to science and their faith do experience dissonance: read the testimonies of those who finally abandoned their their faith after learning about science, or of those priests who left the cloth when they couldn’t comport their faith with reality.
But put all that aside. Giberson is just playing a word game here to avoid tackling the real question, the question that I broached in our debate—science and faith are philosophically incompatible. Accommodationists pretend that these are equally valid “ways of knowing”, but they actually differ radically in how they attain this “knowledge” (I’d claim that faith produces no knowledge at all), and in how they buttress it when answering the questions, “What’s the evidence for what I think is true?” and “How would I know I was wrong?” There are many religions, all making incompatible assertions about what is true, but there is only one science.
I’ve belabored these points ad nauseam here and elsewhere, but accommodationists like Giberson won’t deal with them, despite my having explicitly defined what I mean by “compatibility.” They’d rather quibble about semantics. (By the way, Dr. Giberson, I didn’t mean that religious scientists were as bad as pedophilic priests.)
Let’s rewrite Giberson’s paragraph about the happy religious scientist:
A religious scientist functions routinely as a “naturalist” in the lab, perhaps looking for the gene that causes Alzheimer’s. While doing this, he refuses to accept any conclusion that isn’t supported by data. One of his students wants a particular gene to be involved, since he’s working on it, but the r.s. tells him that wish-thinking isn’t enough. There have to be hard data—perhaps through association studies—that can either implicate that gene or rule it out. On Sunday this scientist goes to church, where he prays for the health of his mother, assuming against all evidence that someone Up There hears his prayer and is kindly disposed to answer it. He has a sip of wine and eats a cracker, assuming without evidence that these substances have been magically transformed into Jesus’s blood and body before consumption. Later on, he goes into a little booth and tells a hidden priest that he masturbated twice during the week. He believes, without evidence, that if he doesn’t confess to this diddling he’ll be immolated for all eternity in molten sulfur.
I’d call that intellectual dissonance. And it explains why American scientists are far less religious than the American public.
In the U.S., academic salaries at state universities are a matter of public record, but they’re usually very hard to find. Now some of them have been put online. If you’re an academic, go here for hours of fun comparing your pay to everyone else’s.
Gloat as you discover that your scientific enemies make less than you! Cringe as you see how much membership in the National Academy of Sciences boosts your pay! Gnash your teeth when you see Steven Weinberg’s haul at the University of Texas!
Note: you can search by department or the individual’s name (faculty).
It’s a positive review, which is good. As a science journalist, Weiner is up there with Carl Zimmer as someone who really grasps the science he’s writing about, though Weiner’s prose sometimes shades, as is common in science journalism, towards the purple.
I did a double take when I first read this excerpt:
Yet evolution has equipped us with bodies and instincts designed only to get us to a reproductive age and not beyond. “We get old because our ancestors died young,” Weiner writes. “We get old because old age had so little weight in the scales of evolution; because there were never enough Old Ones around to count for much in the scales.”
But then I realized that what Weiner means by “getting old” is not an increase in years, but the phenomenon of senescence—those changes in the body that occur with ageing. He’s apparently referring to two evolutionary theories of senescence: we fall apart because mutations that make us fall apart were never selected against in our ancestors, who had a limited life span (the “mutation accumulation” theory); and the idea that natural selection might have promoted the accumulation of mutations that trade off increased reproduction when you’re young with degeneration when you’re old (the “antagonistic pleiotropy” theory). In both cases a high mortality in ancestors (due to disease, accidents, malnutrition and the like) could favor the evolution of senescence in descendants.
I must say that it’s not much consolation to realize that the aches and pains that start afflicting us around age 35 are the byproducts of natural selection.
An email from a reader, complete with new pictures of cute wild cats, prompted me to throw this week’s spotlight on the Canada lynx.
There are four species in the genus Lynx, two of which (the Canada lynx, L. canadensis, and the bobcat, L. rufus) occur in North America. The bobcat—once lumped with the Canada lynx in a single species—is far more common in the U.S. Most Canada lynx live farther north, where they prey on snowshoe hares and other mammals. (The tandem and regular oscillations of lynx and hare abundance, with a cycle of about ten years, is a famous story in ecology, which, as far as I know, is still unexplained.) Like most wild cats, they’re shy and solitary, so their biology is not terribly well understood.
Both American lynxes are medium-sized cats (20-30 lb) with tufted ears, very short tails (hence the name “bobcat”), huge paws (which, as you’ll see in the video below, act as snowshoes in winter), and a bushy mane around the jowls that gives them a regal and leonine appearance:
Peter Vickery, a biologist and president of The Center for Ecological Research, kindly agreed to share his story (and the three following photos) about surveying the Canada lynx in his state:
I was invited by the Maine Dept. of Inland Fisheries and Wildlife and USFWS researchers to join them looking for Canada Lynx dens in northern Maine. The Lynx Team (MDIFW and USFWS) has been studying lynx in northern Maine for 11 years, documenting breeding and productivity, survivorship, and habitat use.
To determine productivity, the Team has put radio collars on a number of females. If the females are denning, their movements become very limited in May and early June. When the general area of a potential den is identified, several members of the Team try and locate the female using receivers. One member then goes in slowly to search for the den. This often requires a game of approach and departure. Once the team member gets reasonably close, the female lynx often moves off. The researcher then moves off and the lynx returns. By doing this several times and carefully following the female’s movements, the researcher can get a pretty good idea of the search area and then the slow process of working through dense regenerating clearcuts begins.
My impression and conversations with Team members indicate that dens are nearly always in regenerating clearcuts or heavy brushy blowdowns. Lynx clearly use clearcuts as denning habitat, presumably because the hare densities are high and nearby, and the dense cover provides excellent shelter for a den. The industrial forest in northern Maine appears to provide plenty of early successional habitat for hare and lynx.
On the day I joined the Team in mid-June, we failed to find a den in the morning because that particular female moved about in an irregular fashion and it was impossible to pinpoint a potential den site. We tried a careful sweep and found old den sites but it may have been that the female had moved the kits, as they often do once the kits are old enough to move.
The second den search was successful, as you can see. The Team uses medical gloves as they take a variety of measurements before the kits are returned to the den. The Team then monitors the female’s movements to make sure she returns to the den. The Team has never had a case of den abandonment. Sometimes the females are close enough, within 4 meters, to observe the Team handling the litter but they are usually some 30 – 50 meters from the den while the Team is present. I’m guessing the female does a huge amount of licking once she returns! Despite efforts to minimize human contact, there must be some foreign smell that a diligent mother would want to remove.
It appears that 2010 is a pretty good year for lynx productivity in Maine. Litters this year are in the 2 – 3 kit range where a few years previously some females didn’t have any offspring. Litter sizes were larger earlier in the study. Not surprisingly, the number of kits is very closely linked to hare densities. I can attest to reasonable hare numbers this year as I saw well over 150 animals on a 60 mile evening drive along the wood roads the night I left the Lynx Team.
The Lynx Team follows the family in the winter once there is snow on the ground. Because the adult female has a collar, the Team can find where they cross a wood road and then back track to determine how many young are still with the female. I was impressed that this was an effective way to monitor kit survivorship through the first winter. The Team always back tracks so they don’t interfere with the animals. Females separate from the young lynx as the new breeding season approaches in early spring.
Regrettably, this is the last year of the study. It’s clear they have gathered an enormous amount of important information relating to productivity and habitat use.
I was very grateful to accompany the Maine Lynx Team and was enormously impressed with their skill, perseverance, and care for the rare animals they were studying. This was a very dedicated and caring group of field biologists! It was a privilege to join them.
Here’s Peter with one of the babies:
I’ll close with one of the most impressive wildlife pictures I’ve ever seen: a lynx catching a snowshoe hare, photographed by Robert Walch for the Time-Life book The World’s Wild Places: The American North Woods (1972). Look at the size of those paws!
And two lynx videos. The first is the classic duel between lynx and snowshoe hare:
And here’s a seriously peeved lynx. The book Wild Cats of the World reports that these beasts make a variety of sounds, some of them completely unexpected. This one (which may be a bobcat) seems to be growling and bleating at the same time.
