Do chimps know death?

April 30, 2010 • 6:40 am

I’ve always said that we are the only species whose members know they’re going to die.  I’m not sure that’s true, of course, but there have been suggestions that some mammals, even if they don’t grasp their own personal mortality, at least understand that death is something final and unique.

Two years ago, Natalie Angier of The New York Times had a piece on this issue, prompted by the death of a baby gorilla in a German zoo whose mother continued to carry the corpse for days, refusing to surrender it to keepers.  Angier mentioned work by Karen McComb and her colleagues showing that African elephants preferentially fondle the bones of dead elephants as opposed to bones from other species.

The latest issue of Current Biology has two thanatological notes (thanatology is the scientific study of death) suggesting that chimps, our closest relatives, perceive death as something unique. The first, by Dora Biro et al., is straightforwardly called “Chimpanzee mothers at Bossou, Guinea carry the mummified remains of their dead infants.” The authors report that, in 2003, a respiratory disease killed several chimps in a free-living colony in Bossou.  Two of the dead were infants, 1.2 and 2.6 years old.  In both cases the mothers continued to carry the dead babies around for several weeks, despite the putrefaction of the corpses.  Mothers continued to treat the bodies (which eventually mummified) with care, grooming them and chasing away flies, as well as carrying them in a unique way, gripping the arms of the dead infant between the mother’s head and shoulders (Fig. 1).

Fig. 1.  A. Mother carries corpse of her baby who died 17 days earlier. Notice the unique carrying posture.  B.  Head of mummified infant who was carried for 68 days after death.

The authors speculate that the mothers knew the babies were dead:

An obvious and fascinating question concerns the extent to which Jire and Vuavua “understood” that their offspring were dead. In many ways they treated the corpses as live infants, particularly in the initial phase following death. Nevertheless they may well have been aware that the bodies were inanimate, consequently adopting carrying techniques never normally employed with healthy young (although mothers of handicapped young have also been known to respond appropriately).

I’m not sure that carrying a corpse in a unique way betokens an understanding of death; maybe it’s just the best way to tote around a nonmoving infant who doesn’t smell too good.  But it is intriguing.

The second report, “Pan thanatology,” describes the behavior of a group of captive chimps when one of their members, a 50-year old female called Pansy, expired peacefully.  After describing the behaviors, the authors reiterate them, drawing parallels with human behavior:

During Pansy’s final days the others were quiet and attentive to her, and they altered their nesting arrangements (respect, care, anticipatory grief). When Pansy died they appeared to test for signs of life by closely inspecting her mouth and manipulating her limbs (test for pulse or breath). Shortly afterwards, the adult male attacked the dead female, possibly attempting to rouse her [7] (attempted resuscitation); attacks may also have expressed anger or frustration (denial, feelings of anger towards the deceased). The adult daughter remained near the mother’s corpse throughout the night (night-time vigil), while Blossom groomed Chippy [Blossom’s son] for an extraordinary amount of time (consolation, social support). All three chimpanzees changed posture frequently during the night (disturbed sleep). They removed straw from Pansy’s body the next morning (cleaning the body). For weeks post-death, the survivors remained lethargic and quiet, and they ate less than normal (grief, mourning). They avoided sleeping on the deathbed platform for several days (leaving objects or places associated with the deceased untouched).

This is a bit anthropomorphic to me, but doesn’t exceed the bounds of informed speculation.  Indeed, the BBC News headline this description as “Chimps ‘feel death like humans'”, and of course it shows nothing of the sort.  (The BBC link has a video of the death, which, unfortunately, you can’t access in the U.S.  If you do have access to Current Biology, you can see two videos here, including a male attacking Pansy’s body.) UPDATE: The videos are now on YouTube and I’ve embedded them below.

What the BBC headline misses is the ineluctable fact that even if we observe behaviors in other species that are similar to our own, we cannot understand what is going on in the consciousness of chimps. Are they grieving? We won’t know until we can teach chimps to communicate in a sophisticated way with humans, or, more easily but less usefully, observe a similarity in brain activity between the two species evoked by the occurrence of a death.

Although many atheists see our knowledge of death as a blessing, making us realize that life is ephemeral and we should live it to the fullest, I see it as a curse. It takes a certain amount of courage to face the fact that one day we will lose everything we have.  Few of us, I think, are enough like Socrates to accept our mortality with equanimity.  Yes, our consciousness is gone when we die, and yes, we don’t agonize about our absence from the scene before we were born, but I for one would choose immortality or, barring that, at least merciful ignorance of my finitude.

___________

Three chimps surround Pansy as she dies:

A male attacks Pansy’s corpse:

Anderson, J. R., A. Gillies, and L. C. Lock.  2010. Pan thanatology.  Current Biology 20:R349-R351.

Biro, D., T. Humle, K. Koops, C. Sousa, M. Hayashi and T. Matsuzawa. 2010. Chimpanzee mothers at Bossou, Guinea carry the mummified remains of their dead infants. Current Biology 20:R351-R352.

h/t: Matthew Cobb’s Z-letter.

Greatest nature photographs?

April 29, 2010 • 10:09 am

Lately the Guardian is into nature photographs, and some lovely snaps they are.  First is their presentation of the ten greatest nature photographs of all time.  I can’t get on board with all of their selections, but there are some undeniably great pictures.  Here are two:

Fig. 1. Galápagos tortoises (Geochelone nigra) having a dip at dawn on Isabela island.  Photograph by Frans Lanting.

Fig. 2: A swimming polar bear (Ursus maritimus)—and its reflection—off Baffin Island.  Photograph by Paul Nicklen.

And, at another site, the Guardian has 21 nice photos of microscopic marine life. Here’s one:

Figure 3:  A larval spider crab (family Majidae, species unknown). Photograph by Cheryl Clarke-Hopcroft.

h/t: Matthew Cobb

In the TLS, F & P-P claim an “egregious misreading”

April 28, 2010 • 1:12 pm

by Matthew Cobb

In the letters page of this week’s issue of the Times Literary Supplement, Fodor and Piatelli-Palmarini reply to the trashing of their book by Samir Okasha. Surprise, surprise, Okasha didn’t understand what they were saying – “an egregious misreading”. For most of us, if someone doesn’t understand the point we’re making, it’s because we haven’t expressed ourselves in the right way… Some philosophers seem to think that any misunderstandings are inevitably the fault of the reader. Who finds their riposte convincing? I hope Okasha comes out fighting.

Sir, – Samir Okasha’s review of What Darwin Got Wrong (March 26) contains a number of serious criticisms of a line of argument the conclusion of which is that there is something radically wrong with Darwin’s Theory of Natural Selection (TNS). Since we do think that there is something radically wrong with TNS, this would worry us a lot if the argument that Okasha deconstructs were even remotely like the one to which our book is committed. But it’s not. Okasha’s review is a really egregious misreading of the book; we don’t hold (and didn’t publish) the views that Okasha says we do. In fact, we explicitly don’t hold these views, and we devote a lot of the book to explaining why no one should. We know from experience that reviewing is hard work and that it conduces to fast reading. But still.

Here is the most flagrant example: “. . . Fodor and Piattelli-Palmarini insist that . . . there is no basis on which to distinguish the selected-for traits from the free-riders. This distinction could only be drawn, they argue, by invoking an intelligent designer . . .”. If words were the kinds of things that can be false, every one of those would qualify. In particular, we think (as does Okasha) that the selected-for traits are the ones that causally contribute to fitness. We take this to be common ground for everybody involved in the present conversation, Darwin included. For present purposes, it’s OK with us if you take that to be true by definition. (This does not, of course, commit us to accepting that any traits are selected-for; only that, if any are, then they are causes, not just correlates, of fitness.) Nor do we think that the distinction between causes and correlates can only be made by invoking an intelligent designer. To the contrary, we devote a whole chapter (Chapter Seven) to discussing some of the ways in which causes and correlates are routinely deconfounded, both in science and in everyday life. Running control experiments, formal or informal, is the standard technique; and there are many, many others. But (so we argue) only things with minds can run experiments; and since it is also common ground that Natural Selection hasn’t got a mind, distinguishing causes from confounds by running experiments isn’t among its options. Likewise for all the other ways of distinguishing among confounded variables that we could think of. If we’re right about that, then the conclusion isn’t that there is an intelligent designer; it’s that there is something wrong with TNS. So, then, our view is not that it is impossible to deconfound causes of fitness from freeriders. Still less is it that there is no such distinction. What we do think (and what we do think our book shows) is that Darwin’s theory can’t specify a mechanism by which selection could reliably distinguish causes of fitness from correlates of causes of fitness. This is not, to repeat, because there is no such distinction; it’s because TNS recognizes only exogenous variables as selectors, and the only (relevant) fact to which such variables are sensitive, according to TNS, is the strength of the correlations between phenotypic changes and changes of fitness. And, of course, correlation doesn’t imply causation. It patently doesn’t in the kind of cases we discuss, where phenotypic traits are linked, so that the correlation with fitness is identical for both of the candidate causes.

Our difficulty with Darwin is very like our difficulty with our stockbroker. He says the way to succeed on the market is to buy low and sell high, and we believe him. But since he won’t tell us how to buy low and sell high, his advice does us no good. Likewise, Darwin thinks that the traits that are selected-for are the ones that cause fitness; but he doesn’t say how the kinds of variables that his theory envisages as selectors could interact with phenotypes in ways that distinguish causes of fitness from their confounds. This problem can’t be solved by just stipulating that the traits that are selected for are the fitness-enhancing traits; that, as one said in the 1960s, isn’t the solution; it’s the problem.

We have other complaints as well. Three examples: we do not hold a “covering law” view of scientific theories; we are explicit that we don’t. What we hold is that if there were laws of selection, that would solve the problem of reconciling TNS with the intensionality of “select-for”. But we don’t think there are such laws in biology, and Okasha doesn’t either. Also: we disapprove of Okasha’s appealing to the “paradigm” explanatory power of mathematical models of natural selection to rebut our objections to TNS. Models don’t even purport to reveal the mechanisms that underlie the phenomena they’re models of; and our claim is that no mechanism could do what TNS says natural selection does. Also: Okasha summarizes several recent discoveries in biology that our book recounts. He sets them aside saying (correctly) that “they simply concern aspects of biology about which traditional neo-Darwinism didn’t have much to say”. But our point about these discoveries is not that neo-Darwinists ignore them; it’s the marginalization of TNS that they imply; it seems the action is mostly in a different part of town.

There is, however, one place where we admit to a fair cop. Samir Okasha chides us for not telling our readers about the distinction between “random” variation and “undirected” variation. Guilty as charged. But that isn’t because, as Okasha graciously suggests, we don’t understand the difference; it’s because we try not to make readers attend to distinctions which, though perfectly valid, aren’t germane to the topic being discussed. Insisting that readers should is just the sort of thing that gives pedantry a bad name.

JERRY FODOR
Department of Philosophy, Rutgers University, New Jersey 08903.

MASSIMO PIATTELLI-PALMARINI
Cognitive Science Program, University of Arizona, Arizona 85701.

Yeast, evolution, and medicine

April 26, 2010 • 3:57 pm

In the past I often said that the importance of evolutionary biology is not measurable in the hard currency of human welfare—that evolution’s value was not in making us richer or healthier, but in giving us the true story of how we got here and when, and who we’re related to.  I’ve tempered that opinion over the years as I’ve become aware of the real contributions evolutionary biology has made to medicine (see for example my exchange with David Hillis).

In today’s New York Times, Carl Zimmer gives further evidence of how evolution is advancing medicine.  Zimmer tells the story of Ed Marcotte at the University of Texas, and how his work on yeast, combined with the concept of deep homology between yeast and human genes, has enormous promise for medicine—everything from cancer to genetic defects.   It involves going back and forth between species, with the iterations finding ever more genes that might be involved in human diseases; and it all rests on the proposition that genes in humans that do one thing might be evolutionarily related to genes in other species that do different things. (This, of course, is one of the observations that has been used to refute Intelligent Design’s notion of “irreducible complexity.”)

It’s way cool.

Boobquake

April 26, 2010 • 2:34 pm

Okay, we all know that Blag Hag (Jen McCreight) had the bright idea of “Boobquake,” a way to make fun of a Muslim cleric’s accusation that immodestly dressed females cause earthquakes.  Jen jokingly suggested a “scientific” experiment in which women would test this hypothesis by showing their breasts today on the internet and looking for an increase in seismic activity. (Actually, this isn’t really a test of the cleric’s idea, since he blamed earthquakes on the adultery attendant on display of boobage):

“Many women who do not dress modestly … lead young men astray, corrupt their chastity and spread adultery in society, which (consequently) increases earthquakes,” Hojatoleslam Kazem Sedighi was quoted as saying by Iranian media.

Regardless, the idea has been taken up with approbation by some of my favorite bloggers, including P.Z., erv, and Russell Blackford.  How do I feel?

I can’t get behind it.

Call me humorless, call me a militant pro-feminist, call me a prude—call me what you want, but somehow the idea of women mocking religion by showing their breasts comes perilously close to making points through sexuality instead of through good arguments and brains. (Just imagine how tepid the response would be if, in the same cause, all of us male bloggers decided to show ourselves in jockstraps).  The predictably leering response of men, who of course have tendered enthusiastic thanks for the mammaries, just confirms this suspicion.

What’s worse is that some women who don’t want to participate in this affair have been derided as anti-sex.  Even Russell Blackford took this tack:

Unfortunately, there was a lot of 1980s pseudo-feminism that took a similar attitude to that of Christianity and Islam, problematising displays of female beauty and even expressing disgust with heterosexuality itself. The worst offender was the egregious Andrea Dworkin – who died relatively young back in 2005. In her case, good riddance. These pseudo-feminists merely use feminist-sounding language to rationalise the religion-based anti-sex morality into which they were socialised. But they lack the self-insight to understand that it’s what they’re doing.

Look, Russell, if you really think that male and female bodies are both beautiful, why do you suppose that this event is getting much more publicity than would a similar display of male skin? Do you think CNN would be all over the event if it was men who were showing their junk? Of course not—and you know why.

And do you really want to tar women who object to selling ideas with sex as acolytes of Andrea Dworkin?  That’s simply unfair.  Some women don’t want to bare their mammae, and NOT because they have a “religion based anti-sex morality”; they simply have good reason to think that in the long run such stunts will hinder women being taken seriously as thinkers and colleagues.

I have to agree with the take of Miranda Hale at Exquisite With Love,  who is an atheist and a feminist, but won’t be doffing her duds today:

The idea is fantastic and well-intentioned. It points out both the ridiculousness of the cleric’s claim and the despicable and harmful practice of blaming all sorts of horrible things (including sexual assault) on women.

However, the great majority of the responses to this effort have been anything but fantastic. Instead, it has inspired, primarily at its Facebook event page, many comments of the “show us your tits!” or “Dude, awesome, I’ll get to see some boob photos on Monday” variety. And, for some reason, women are complying. They’re posting photos of their cleavage and men are responding with “awesome boobs!”, etc. The Facebook event page has almost 200,000 “attendees” and the effort has received a great deal of media coverage. And that’s all well and good, but how many of these individuals are actually concerned with raising awareness of this issue? Very, very few, I’d say.

Sure, one can assert that the event has been unfairly “hijacked” by the men who are reacting in this way, but this response wasn’t hard to predict. And although the men making these types of comments are solely responsible for the attitudes expressed in them, why provide them with fodder? I understand that this is intended to be a lighthearted attempt to point out the ridiculousness and stupidity of the assertions made by the cleric, but that intention has been completely buried under a constant stream of “show us your tits” comments. . .

. . . Let’s dress however we want to, let’s be as modest or as immodest as we choose, and let’s use our sexuality however we see fit. It’s all about choice. If Boobquake is your kind of thing, then, by all means, enjoy it. But don’t stop there. Write about these issues. Raise consciousness about them. Speak out against the “show us your tits” reactions. And please don’t pretend that merely showing as much cleavage as possible is somehow making any kind of difference. It’s not.

If it doesn’t make a difference in promoting atheism and mocking faith, what good is it? It’s just Playboy on the internet.

UPDATE:  Ceiling Cat weighs in.

This is what college should be.

April 26, 2010 • 2:28 pm

by Greg Mayer

Several days ago, while walking to my car past a small patch of woods adjacent to the building where my office is, one of my students called to me from the woods. He has been working on various projects, and this year has been pretty much in charge of a project to monitor the abundance  of an invasive exotic crayfish in a local pond. He was sitting on a chair in the middle of the woods, and as I approached him I noticed two bird feeders hanging in trees nearby. He explained that he was working on a lab for his animal behavior course, but had seen few or no birds that morning. Surveying the woods, I noticed how open it was because the canopy trees had not yet leafed out, and very few of the understory trees or shrubs had either. There were, however, quite a few flowering herbaceous plants, and, seeing how the birds were scarce, we took a look at the flowers. They were unevenly distributed over the forest floor, with large clumps or colonies here and there. We wondered about this– were there subtle habitat differences we could not immediately see that determined where the plants grew?  Or perhaps they reproduced clonally, and each patch was where a successful individual had landed.

Bloodroot- the start of it all. Photo by UpstateNYer from Wikipedia.

While I take some pride in my knowledge of local trees, forest herbs are not my forte. The student said he thought the plants nearest us, with white flowers and lobed, shamrock-like leaves, were bloodroot. He plucked one, and sure enough a reddish sap was evident in the stem. We looked around a bit more, and found some Trillium, too. About this time a graduate student who also works in my lab was walking down a path through the woods, and we called him over, and showed him the plants we’d found. I told the students about how this was a good time to be in the forest, because you see much further before the understory leafs out, allowing you to see the topography and the distribution of the big canopy trees at a glance, as well as the flowering herbs, some of which are ephemeral and will soon die back, but others of which will, after flowering early, keep their green leaves all season.

I mentioned to the students that I’d seen a great web post that morning about first contact with aliens (h/t: PZ), which stressed the likely lack of similarity and extreme technological disparity between us and interstellar travelers (“nuclear weapons [used by them] vs. sponges [which would be us]”), and how a binary code would be the way to communicate, although PZ noted they’d probably collect several specimens for the interstellar natural history museum before they figured out the sponges [that would be us] were sentient. The grad student suggested that it wouldn’t be that bad, since convergent evolution would insure that they had some basic similarities to us. I said I’m not so sure, and noted that George Gaylord Simpson, in his famous essay on the nonprevalence of humanoids (link might require subscription), had argued strongly that life elsewhere is decidedly unlikely to be familiar to us. We discussed what basic similarities there might be among life forms evolved completely independently.  Bilateral symmetry?  Common on earth, but how many times had it evolved independently here? Cephalization? There were some interesting cases of it evolving in primitively radial urchins. Carbon based?  It beats silicon, but there was the Horta on Star Trek. The grad student recalled how Star Trek “explained” the prevalence of humanoids by having the “ancient humanoids” seed the galaxy with DNA that would lead to the evolution of humanoids. This, I noted, is no explanation at all, but it did show the Star Trek producers were aware of the thrust of Simpson’s critique.

We went on to note that there were ways of trying to distinguish independent from convergent origins. Shared, yet arbitrary, characteristics, such as the genetic code, suggest a single origin (unless of course there are functional differences among possible codes, which would make them non-arbitrary), while clearly adaptive similarities might arise through convergence (see whales and icthyosaurs). About this time we all realized we had other things we were supposed to be doing– meetings, lectures, etc. So we split up, and headed for our varied destinations. As we did, the first student said, “This is what college should be.”