Category: evolution

A new review (and critique) of Richard Prum’s book on sexual selection

August 30, 2018 • 9:01 am

I’ve now read Richard O. Prum’s new book, The Evolution of Beauty: How Darwin’s Forgotten Theory of Mate Choice Shapes the Animal World—and Us (I’d highlighted the work earlier in my critique of his NY Times article about the book). Click on the screenshot to go to the book’s Amazon site. (Prum is a professor of ornithology, ecology, and evolution at Yale.)

The review I want to highlight was published in the journal Animal Behaviour, but I’ll get to that in a minute. First, I want to give my own brief take on the book.

The Evolution of Beauty is in fact a mixed bag, but for me the problems outweigh the good parts. First, though, what’s good, and a bit of background.

Prum’s purpose is to explicate a theory of sexual selection that was suggested by geneticist Ronald Fisher eighty years ago and was elaborated much more recently by my colleagues Russell Lande and Mark Kirkpatrick. (Prum also draws a line of descent to this theory from Darwin’s own views of sexual selection published in 1871.)

This theory—the “runaway model”, called by Prum the “Beauty Happens” model—tries to explain why males are ornamented and show displays, while females choose among those males. This is sexual selection, which Prum (mistakenly, in my view) says is qualitatively different from natural selection (see my earlier post for my take on this pseudo-distinction). Prum’s view is that the runaway process, in which females evince randomly generated “aesthetic” preferences for male traits, have been the “ubiquitous” cause of sexual ornamentation and displays in animals. (His examples are drawn largely from birds, but he applies them to humans in the book’s final chapters.) The male traits and female preferences get exaggerated because they are genetically correlated: those females with preferences mate with males having the preferred trait, and the offspring carry genes for both the preference and the male trait. This causes a snowballing process that exaggerates both trait and preference to the extremes that we often see in nature.

Prum contrasts the runaway process with other forms of sexual selection in which females choose males not because they’re “beautiful” (to Prum that word that simply means “what appeals to females”), but because the offspring of females get benefits from her choice: either genetic benefits (“good genes” models) or “direct benefits” (healthy males can better take care of offspring or don’t pass parasites onto the mother and hence onto her young). These models, in which male traits and behaviors indicate the health or genetic quality of a male, are known as “indicator models”.

There are also other models that are either well known and substantiated (“male-male competition”, which causes sexual dimorphism and ornamentation, including antlers in deer, larger body size in competing male elephant seals, and so on), or more speculative but still credible models (“sensory exploitation,” in which female preferences are a byproduct of behaviors that existed for other reason, like preferring colors that resemble berries). There is in fact evidence for nearly every model of sexual selection, but it’s so hard to do this kind of work that we simply cannot say, as does Prum, that one scenario is “ubiquitous.” It’s early days here, and Prum’s suggestion that we know the answer is premature, though in the end he may be right. Or other models may be right. Or the answer may be that different models contribute to sexual dimorphism in varying degrees, or act together. We just don’t know.

The good aspects of Prum’s book include a historical overview of the difference between Darwin and A. R. Wallace in their views of sexual selection, and a critique of the many modern behavioral ecologists who uncritically adopt “good genes” models as the default explanation for sexual dimorphism. Further, Prum’s descriptions of male traits and behaviors, most seen by him in the field, are superbly written and often mesmerizing.

The book’s problem is that it is tendentious. Prum doesn’t describe the issues with his favored runaway model; he mistakenly regards it as a “null model” against which other models must be tested since, he wrongly claims, it makes no assumptions (he also claims that his null model can neither be proven nor disproven, which makes it non-scientific); he neglects other forms of sexual selection; he does not recognize that various models can work together and likely do work together; he ties “good genes” models to eugenics and even Nazi eugenics, unfairly tarring sexual selection theory with the residue of an unsavory past; and he claims that female choice of mates, which he calls “sexual autonomy”, somehow vindicates feminism in our own species.

The tie to feminism is a particularly invidious way to sell his theory, as female choice in birds is a direct product of evolution, while human feminism is a rational conclusion our species draws to improve society by treating people equally. Feminism should not be buttressed by biology, as that makes it susceptible to further knowledge from biology. If you study other species, for example, you could draw other conclusions and support other forms of sexual behavior in humans. Many species, for instance, have “traumatic insemination,” in which the male simply bypasses female choice by either forced copulation or, in the case of bedbugs and some invertebrates, injects the sperm directly into the body cavity, bypassing her genitalia and often injuring or killing her. Here are two bedbugs going at it, with the smaller male sticking his genitals directly into the female body cavity; you can see the puncture wound he’s making. (The sperm somehow still find their way to the eggs.)

If you studied deer or elephant seals, you might find support for the existence of harems in humans, in which powerful males, by virtue of their status, are able to dominate and mate with many women, while the “losers” go childless. This underscores the big mistake of using your favorite brand of biology to support ideological or moral conclusions. (I note that biology can, however, inform some aspects of morality: learning about fetal pain may, for instance, affect one’s views about abortion.)

Nevertheless, the problems with Prum’s book are so serious that it distresses me that it’s gotten such good and uncritical reviews. The New York Times, which gave it a glowing and uncritical review, selected it as one of the Ten Best Books of 2017.  It was also one of three finalists for the 2018 Pulitzer Prize in General Nonfiction (it didn’t win), which convinces me that those who choose these candidates don’t know much about the books’ subjects. I’m starting to realize that magazines and websites should choose scientists, or at least people who deeply understand the science at issue, to review trade books about science.

But enough; I will likely give a fuller explication of my views in the future. For now I want to highlight a newly published critique of Prum’s book by Gerald Borgia and Gregory Ball, two researchers from the University of Maryland who work on mate choice in bowerbirds. (Borgia is my former colleague.) Their review of The Evolution of Beauty occupies a page and a half in the latest issue of Animal Behaviour. The reference with link (also here) is below, and the pdf is here; both are free to me with Unpaywall, but if you can’t download them, a judicious inquiry might yield you a pdf.

Borgia and Ball’s criticisms are similar to mine, but as they are experts, they go far beyond what I’ve written above. If you know about sexual selection it may be an easier read, but if you’re interested in sexual selection I suggest you give it a try. At any rate, at the end of their review, Borgia and Ball raise the feminism and eugenics angles, and the excerpt below should be comprehensible to everyone. I’ve put in bold a particularly misguided quote from Prum:

In the last chapter of Beauty, Prum reveals the political view that has shaped the core arguments in this book. Prum’s style and message is a rerun of Gould and Lewontin’s divisive writings from 40 years ago, in which they unfairly associated adaptationism with genetic determinism, eugenics and Nazi atrocities (Allen et al.,1975, p. 186). Prum applies similar arguments to sexual selection, associating good genes and adaptive mate choice hypotheses with eugenics and Nazi violence. He states: ‘To permanently disconnect evolutionary biology from our eugenic roots, we need to embrace Darwin’s aesthetic view of life and fully incorporate the possibility of nonadaptive, arbitrary aesthetic evolution by sexual selection. “…Accordingly, evolutionary biology should adopt the nonadaptive, Beauty Happens null model of the evolution of mating preferences and display traits by sexual selection”(page 331).

That’s incredibly dumb. What it says is that we should adopt one scientific theory over others (surprise!—it’s Prum’s favored theory) not for scientific and evidential reasons, but simply because that theory can’t be tied to discredited views of eugenics. Borgia and Ball continue:

Prum’s conflation of eugenics and genocide with adaptive mate choice is a disservice to his readers and colleagues for several reasons. First, this argument is wrong. Mate choice represents individual, and especially female, reproductive freedom, whereas eugenics and genocide represent a restriction by the state on an individual’s ability to live and reproduce. It is not more moral to choose a mate  for arbitrary reasons, as Prum suggests, than to choose one to enhance the success of one’s offspring. Consistently across societies, parents support the interests of their offspring, suggesting that adaptive mate choice may be viewed as morally superior. Second, Prum’s mistaken association of eugenics with adaptive/good genes mate choice represents a threat that can limit free scientific discussion of important issues, and this should be resisted. Third, science validates or rejects hypotheses based on evidence, not on potential or contrived historical associations, altruistic intent, or political belief.

We offer two key takeaways from this book. First, contrary to Prum’s claims, LK [“Lande-Kirkpatrick”] runaway selection has enjoyed a privileged position, including being prominently presented in evolution and behaviour textbooks despite a lack of supporting evidence. Perhaps the most significant implication of Beauty comes from Prum’s inability to make a credible case for LK runaway sexual selection in this book’s 448 pages, suggesting that it may be time to shift focus to other, better-supported models. Second, Prum’s (and other, earlier) efforts to inject politics into science commonly distort the science to justify political goals. We should have all learned by now that science is about understanding what nature is, not what we want it to be. The arguments in Beauty that suggest otherwise should be rejected.

That’s a fine ending of a good review—and by that I mean a thoughtful review.

Here’s a 7-minute Big Think video in which Prum explains his views. His drawing a connection between eugenics and adaptive theories of mate choice begins about 2:10. He continues, tying the theories he opposes to eugenics and racism (and to his view that sexual selection differs from natural selection), at about 4:50.

h/t: Nilou, Tami Mendelson

________

Borgia, G. and G. F. Ball. 2018. Review of The evolution of beauty: how Darwin’s forgotten theory of mate choice shapes the animal world—and us.  Animal Behaviour 137:187-188.

 

 

Epigenetics: the return of Lamarck? Not so fast!

August 26, 2018 • 11:00 am

I noticed that there’s a new book out by Peter Ward, a biology professor at the University of Washington who’s done a lot of work on nautilus cepalopods. (He’s also written several trade books in biology.) Here’s his new book, and, as you can see, the cover touts epigenetics as “Lamarck’s Revenge” (Jean-Baptiste Lamarck [1744-1829] was a French naturalist who proposed a theory of the inheritance of acquired characteristics.) The cover also promises to show how epigenetics is revolutionizing our understanding of evolution. Click on the screenshot to go to the Amazon site:

The book has been reviewed in several places, and I noticed that while it got a starred review on Kirkus, Publisher’s Weekly called it a “frustrating book” and has this in its review:

Ward references the classic study showing how starvation impacted one and perhaps two generations in the Netherlands following a WWII-era famine, but provides little hard evidence beyond that example. [JAC: see below for a discussion how even the famine study is flawed.] Without a proposed mechanism for such long-lasting effects and without data indicating such effects exist, Ward leaves readers with little more than suppositions.

And that’s the problem with the Lamarckian/evolutionary/revolutionary hypothesis. Environmentally induced changes to the DNA, usually produced by the placement of small methyl groups on DNA that affect what it does, are almost never inherited beyond one or two generations. This lack of stable change means that such environmental modifications cannot form the basis of permanent evolutionary adaptation. Ergo, it can’t revolutionize our view of evolution.  As the prescient Publisher’s Weekly reviewer noted, there’s just no evidence for the heritability of “Lamarckian” changes to the DNA.

I haven’t yet read Ward’s book, and don’t want to judge it by its cover, but the Nautilus site (the name is a coincidence, and that site was funded by Templeton) has reproduced an excerpt from Ward’s book, which is the article below on “fewer species”. Click on the screenshot to read it. And it gives me no confidence that Ward’s book presents a balanced view of epigenetics.

Lamarck’s Revenge, like David Quammen’s new book on phylogeny, seems to fall into the “Darwin was wrong” genre. (Darwin was supposedly wrong because modern evolutionary theory proposes that either mutations or genes transferred from other organisms are the variational basis for permanent adaptive change, and that the environment cannot itself influence DNA sequences in a permanent way. If environmental methylation did produce gene changes that could be both inherited and adaptive, and so spread through species, it would be a major change in how we view evolution.)

I should add that Darwin himself was “Lamarckian” because he thought the environment could somehow permanently modify heredity, and, as Matthew Cobb reminded me, Lamarck thought the changes occurred not through the environment, but through the animal’s “will.” Both men were wrong about heredity, but, as Matthew suggested, Ward’s book might better be called Darwin’s Revenge! After all, Darwin’s ideas were closer to these misguided epigenetic ideas than were Lamark’s theories.

Click and read:

 

Now the title doesn’t say much about Lamarck or the “evolution revolution”, but the article itself does. The title itself refers to work that Ward did with his colleagues on two species of Nautilus. One species, N. pompilius, occurs widely across the Pacific, while the closely related species N. stenomphalus is found only on the Great Barrier Reef. They were distinguished as different species by differences in morphology: they differ in whether they have a hole through the center of their shell, as well as showing big differences in both internal and external anatomy.

Ward, however says that they aren’t separate species because their DNA was identical using DNA-sequencing analysis (my emphasis):

We caught 30 nautiluses over nine days, snipped off a one-millimeter-long tip of one of each nautilus’ 90 tentacles, and returned all back to their habitats alive (if cranky). All the samples were later analyzed in the large machines that read DNA sequences, and to our complete surprise we found that the DNA of N. pompilius and the morphologically different N. stenomphalus was identical. No genetic difference, yet radically different morphology. The best way to interpret this is to go back to one of the most useful analogies in evolution: of a ball rolling down a slope composed of many gullies. Which gully the ball rolls down (corresponding to the ultimate anatomy or “phenotype” of the grown animal) is controlled by the direction of the push of the ball. In evolution, the ultimate morphological fate of an organism is caused by some aspect of the environment the organism is exposed to early in life—or, in the case of the nautiluses, while they slowly develop in their large egg over the course of an entire year before hatching. Perhaps it is a difference in temperature. Perhaps it is forces that the embryo encounters prehatching, or when newly hatched, the small nautiluses (one inch in diameter, with eight complete chambers) find different food, or perhaps they are attacked and survive, i.e., have two different kinds of predators. That’s why N. pompilius and N. stenomphalus are not two species. They are a single species with epigenetic forces leading to the radically different shell and soft parts. Increasingly it appears that perhaps there are fewer, not more, species on Earth than science has defined.

Well, the differences might not be genetic, but they might not be epigenetic either: the environment could simply change the development of the organism in different places without methylating or modifying its DNA in a heritable way, just as a plant given lots of fertilizer in one plot will grow taller than a plant grown without fertilizer in another plot. There’s no indication here that the differences in morphology of the two Nautilus species are caused by methylation of the DNA or histones, or by small RNA molecules—the three ways Ward says the environment might modify genes in a permanent way.

More important, when I looked up the paper on which this statement was based, I found, contrary to what Ward implied, they didn’t look at a lot of DNA in the two species, finding it identical. The paper (click on screenshot below), published in 2016, looks at only two genes in the mitochondria, and none from the nucleus:

An excerpt from the paper above:

Here, we report the genetic analysis of mitochondrial genes cytochrome c oxidase I (COI) and 16S rDNA, commonly utilized genetic tools for the phylogeographical studies of marine invertebrates, including cephalopods (Anderson 2000; Anderson et al. 2007; Dai et al. 2012; Sales et al. 2013a) from individuals across the known locations of Nautilus populations (Philippines, Fiji, American Samoa, Vanuatu, and eastern Australia – Great Barrier Reef). We chose COI and 16S because of their variability and success in past studies, and to align with sequences generated for this study with previous nautilus studies (Bonacum et al. 2011; Williams et al. 2012). We neglect nuclear genes (e.g., 28S or histone 3) because sequencing efforts have been limited in nautilus, precluding comparative analysis with past studies, and have been shown to be relatively uninformative for phylogenetic studies within this genus (Wray et al. 1995).

Now while the two species might indeed be one, you can’t conclude that from the identity of just two mitochondrial genes. And the Nautilus article at the top implies that a lot of DNA was examined. There may be substantial differences in other parts of the DNA that produce the morphological differences between the two (ergo these differences having a genetic rather than an epigenetic basis), and may even lead them to be reproductively isolated, ergo being two biological species.

I may have missed another paper looking at whole-genome sequences, but I doubt it. To me it seems that Ward is exaggerating his findings, and also implying that they extend to many species on earth, which might not be “biological” species because their differences are based not on DNA, but on developmental differences induced by the environment (and perhaps inherited via methylation). That might be true, but it’s an unwarranted extrapolation from a study of one organism.

Now Ward does mention one well known and important epigenetic property: the development of different cells and tissues in a single organism is often set off by epigenetic modifications that are themselves coded in the genome (i.e., the DNA of gene A says, “turn on/off genes B, C, D, and E under different internal environments”). Those differences are inherited through different cell divisions, which explains why, though all the cells in the body are genetically identical, they do different things and form different tissues. And those epigenetic changes are coded into the organisms’s DNA; they don’t come directly from the environment.

But that applies only to development of a single organism. It’s a very different thing to claim that environmental modification of the DNA of an organism is passed on through its gametes to its children, grandchildren, and so on, for that’s the only kind of environmental modification that can be involved in evolution. And the evidence says that this isn’t likely to happen. As I’ve said  repeatedly, methylation changes (and Ward notes this) are usually wiped out completely when gametes are formed, and we know of NO adaptation that is caused by environmentally-induced methylation of DNA or histones.

Yet in his popular article, Ward goes on to imply that this really does happen, and happens in human evolution as well. Here are a few excerpts (my emphases):

The methyl molecules are not physically passed on to the next generation, but the propensity for them to attach in the same places in an entirely new life-form (a next-generation life-form) is. This methylation is caused by sudden traumas to the body, such as poisoning, fear, famine, and near-death experience. None of these events come from small methyl molecules, but they cause small methyl molecules already in the body to swarm onto the entire DNA in the body at specific and crucial sites. These acts can have an effect not only on a person’s DNA but on the DNA of their offspring. The dawning view is that we can pass on the physical and biological effects of our good or bad habits and even the mental states acquired during our lives.

This is a stark change from the theory of evolution through natural selection. Heritable epigenetics is not a slow, thousand-year process. These changes can happen in minutes. A random hit to the head by an enraged lover. A sick, sexually abusive parent. Breathing in toxic fumes. Coming to God in religious ecstasy. All can change us, and possibly change our children as a consequence.

There is not a lick of evidence for any of that!

And there’s this:

. . . It has long been “truth” that the epigenome (the complement of chemicals that modify the expression and function of the organism’s genes, such as the methyl molecules that can glom onto specific genes during the life of the organism due to some environmental change) of the parent is reprogrammed (all epigenetic traces removed) twice: once during the formation of the gamete itself (the unfertilized egg, or a sperm waiting around to fertilize an egg) and secondly at conception. Erase and erase again. But now experiments definitively show that some of the chemicals added during the life of an organism do leave information in such a way that the offspring has [sic] their genes quickly modified in the same way that the parents did. The same places on the long DNA molecules of the newly born (or even the “not-yet” born) get the same epigenetic add-ons that one or both of the parents had. This is not supposed to happen. The revolution is the realization that it does. It happened to the nautilus. And it happens to you and me.

That is a gross exaggeration, and greatly misleading. If you want to see a good consideration and critique of the purported evidence for transgenerational epigenetic inheritance in humans, read this 2018 Wiring the Brain website post (click on screenshot) by Kevin Mitchell (note: he considers the overblown “Dutch famine” data as well):

Mitchell’s conclusion:

In my opinion, there is no convincing evidence showing transgenerational epigenetic inheritance in humans. But – for all the sociological reasons listed above – I don’t expect we’ll stop hearing about it any time soon.

He’s right on both counts: the evidence is horribly weak, and yet we still keep hearing about “Lamarckian” epigenetic inheritance, this time from Ward. After all, the message “Darwin was right” doesn’t sell books, but, in book publishing, “Darwin was wrong” is the scientific equivalent of “man bites dog”

As it says at the bottom of Ward’s article, these passages are from Lamarck’s Revenge. That doesn’t bode well for the book.

h/t: Nilou

My WaPo review of David Quammen’s new book on evolutionary trees (and a comparison with other reviews)

August 24, 2018 • 11:00 am

I’ve just reviewed David Quammen’s new book, The Tangled Tree: A Radical New History of Life, for the Washington Post. Click on the screenshot to see my review. (Note that the original title, which was a bit misleading, has been changed to the new one below.) It will be in the paper version of Sunday’s Post.

Since the topic of the book is evolutionary trees, in particular their reality (or nonreality, according to Quammen), I asked that my piece be illustrated with Darwin’s famous “tree sketch” from one of his pre-Origin notebooks:

Charles Darwin’s sketch of the “Tree of Life” illustrates his theory that species evolved from a common ancestor. (Photo by Mario Tama/Getty Images)

The point of Quammen’s book is largely that the “tree of life” isn’t treelike, and that’s because of endosymbiosis (e.g., the creation of eukaryotic cells that harbored mitochondria and chloroplasts by ingesting and using other microbes), and, mainly, because of “horizontal gene transfer” (HGT): the movement of DNA between rather unrelated organisms.

Besides this point, Quammen’s protagonist is Carl Woese, who discovered that life really comprises three distinct domains: Archaea, Eubacteria, and Eukarya. Because the book consisted of several distinct stories, I chose to concentrate in my review on what seemed to be Quammen’s main point: that the tree of life is simply “wrong” (his words), and can’t really be represented by a tree. The Tangled Tree falls into the “Darwin was wrong” genre of books.

I disagreed about the unreality of trees, especially in the Eukarya, where assumptions of branching trees have worked well in reconstructing the history of species, despite occasional movement of genes between branches. Even in microbes Quammen isn’t completely correct: while HGT is more common among microbes than eukaryotes, it hasn’t, for instance, completely effaced phylogenetic relationships between bacteria, and of course didn’t prevent Woese from discovering, via DNA sequencing and biochemistry, that Archaea is a separate “domain” from the other two. With a limit of 1200 words, I had to largely ignore the stuff about endosymbiosis and Woese’s discovery to concentrate on the main point of the book: the “hook” that was used to sell it.

You can read my review at the link, or, if you’re paywalled, you can get a copy by judicious inquiry.

I’ll also add one correction to my review. Here’s part of what I wrote:

More remarkably, more-complex species can simply incorporate genes from the environment. Microscopic rotifers, for instance, dehydrate in dry conditions; when they rehydrate, the absorbed water can contain bits of DNA from nearby species, so that the rotifer genome can become riddled with “found” DNA segments from groups like fungi and plants.

The rotifer story now appears to be not at all a case of HGT at all, but of contamination by DNA from other species during sequencing. That was revealed in an article published in Current Biology on August 6, and which I didn’t know about until my article was in press (thanks to Matthew Cobb for pointing that out to me). So even that famous example of HGT is wrong. Some biologists think that most evidence of HGT in eukaryotes is due to contamination of this sort, but I remain open-minded. We already know, as I said, that HGT is not sufficiently frequent in multicellular organisms to efface their evolutionary ancestry.

I want to say a few words about three other reviews that have appeared about Quammen’s book. The first two are at the New York Times (click on screenshots to go to articles):

Seghal is a literary critic, and it shows: she criticizes the book as a piece of writing (she likes it) but doesn’t at all tackle the science. In fact, she admits, if not flaunts, ignorance of the science:

In 1977, Woese and his colleagues at the University of Illinois announced their discovery of a “third domain” of life — single-cell microbes they called archaea — genetically distinct from what were thought to be the only two lineages of life: prokaryotes, which include bacteria, and eukaryotes, which include plants and animals. (It’s O.K., I might have missed the memo, too.)

Missed the memo? If you know the least bit about biology, you know about Archaea. And if you don’t, you shouldn’t be reviewing this book. And there’s this:

But this new knowledge — that we are genetically a mosaic — challenges our conception of human identity. What does it mean to be an “individual,” if we are such composite creatures?

Quammen raises and rushes past these existential questions; like the White Rabbit, he spends some sections in a bit of a mad rush. There’s a “Montana blizzard of facts” he wants to shepherd us through; a dizzying array of scientists, past and present, he must introduce. (Please don’t ask me if I can tell my Norton Zinder from my Oswald Avery.)

This is simple parading of the critic’s ignorance to excuse her inability to discuss the science. It is in fact embarrassing. And she doesn’t grasp the science: there’s not a peep about whether the concept of evolutionary trees are, as Quammen claims, pretty useless.  Seghal’s review is a paradigm for why science books should be reviewed either by scientists or by people who know a fair amount about the science at issue.

Erika Hayden, on the other hand, is qualified to review the book: she’s a science journalist and director of the Science Communication Program at the University of California, Santa Cruz. And her review is better than that of Sehgal, although again she doesn’t weigh the evidence for the existence of evolutionary trees; she takes Quammen’s conclusions at face value.

But Hayden has her own beef: she sees the book as antifeminist:

But if Quammen is writing for the ages, his prose at times risks feeling dated. His book spans nearly three centuries and mentions more than 160 scientists by name. Of those, by my count, only 11 are women, and Quammen often dismisses their scientific credentials and achievements or portrays them as appendages to men in the story.

Lynn Margulis, for instance, fundamentally revised our understanding of eukaryote evolution, elucidating how nature’s most complex cells, including our own, arose when simpler cells joined together. She is the only female scientist who is called out and gets significant space in Quammen’s book. But we hear just as much about her pregnancies, motherhood and marriages as we do about her science.

In contrast, Quammen doesn’t really spend equal time exploring the family arrangements of the male scientists in the book. It’s a classic failure of the Finkbeiner test, formulated by the journalist Christie Aschwanden, which posits that a female scientist’s gender is not her most salient characteristic. If scientists’ family lives are important, journalists should write about the families of both male and female scientists. Otherwise, we perpetuate the stereotype that a woman scientist’s primary responsibility is to care for her family, while men should float free from such pedestrian concerns in their pursuit of research.

As for the imbalance between male and female scientists, that simply reflects the gender composition of the field at the time the work was done. In that sense the book is dated, but not unfair.

I reread those sections, and that on Margulis, to see if Hayden had a point, and concluded that she’s wrong. Margulis’s work was discussed in detail, with her science occupying far more space than a few sentences about her family life, including her marriage to Carl Sagan. (The spouses of male scientists aren’t ignored, either, and I don’t think that the women scientists, who are often praised, are given short shrift.) Quammen’s brief mention of Margulis’s family was meant only to show that she accomplished much of her work when she was a single mother of three children and holding down another job, and was meant to laud her accomplishments during a difficult period of her life. (Margulis, of course, was problematic in other ways, being a 9-11 truther, and someone who pushed her theory of endosymbiosis much farther than she should have. She wrote a book on speciation with her son, for instance, that was so bad that it was the only book I’ve ever refused to review for a major venue. It wasn’t even wrong.) In general, then, I don’t agree with Hayden calling out the book for sexism, but you can draw your own conclusions.

Finally, there’s this review from the New Republic (click on screenshot). Gaffney is identified as “a physician and writer with a focus on health care politics, policy, and history. He is an Instructor in Medicine at Harvard Medical School and a pulmonary and critical care physician at the Cambridge Health Alliance.”

 

Gaffney’s review is good for what it is: a recounting of what the book is about. But it again falls short in evaluating Quammen’s thesis, and says only this (besides a long bit on the transfer of antibiotic resistance among bacteria by HGT):

Ultimately The Tree of Life is merely a metaphor, but I think a pleasant one: It connects us to the lineage of all living things, all the way back to the bag of chemicals—or maybe the single molecule—that one day coalesced in the primordial muck. Yet like all metaphors, the “tree” falls short of reality. For in biology, all boundaries are blurred: between species, sometimes even between individual organisms, and probably between the living and the non-living.

No, not all boundaries are blurred. Homo sapiens doesn’t interbreed with any other species of primate, nor do many, many other species. And really, is the line is blurred between, say, Jerry Coyne and Meryl Streep? How? As for the “unreality” of trees, I disagree. So long as species arise from the transformation of populations, usually geographically isolated ones, the history of life is indeed largely treelike. If it weren’t, we wouldn’t be able to reconstruct the history of life. Yet we can!

Now Quammen’s book has its good points. For one thing, it tells you the nitty-gritty about how science is done, complete with rivalries, jealousies, and backbiting. Quammen did his historical homework. And it’s a well-written story. But as you’ll see from my review, I think his report on the demise of Darwin’s tree is greatly exaggerated.

 

h/t: Stephen

32-year study: Australian students become less creationist and more accepting of evolution, almost certainly because of growing secularism

August 22, 2018 • 10:15 am

This new study at Evolution: Education and Outreach (reference below, free access and free pdf here) reports the results of 32 annual surveys of first-year biology students in at The University of New South Wales (UNSW). Unlike the data from the U.S., which I’ll discuss briefly below, the Aussie data show a tremendous and salubrious change over this period: both creationism and “theistic evolution” (evolution tweaked or guided by God) dropped markedly, while purely materialistic evolution—the “theory” I taught in my classes—has more than doubled in acceptance.

The authors asked the students (average number 530 per year) to tick one of four boxes on a piece of paper, and drop it anonymously in a box as they left the classroom. The questions were designed to mimic those used in the U.S. Gallup polls over the last 35 years, and refer specifically not to evolution in general, but to human evolution. This makes the Australian data comparable to the U.S. data. Here are the questions asked of UNSW students:

  1. God created people (Homo sapiens) pretty much in their present form at sometime within the last 10,000 years.
  2. People developed over millions of years from less advanced forms of life, but god guided the whole process, including our development.
  3. People developed over millions of years from less advanced forms of life. God had no part in this process.
  4. I honestly have no opinion about this matter.

Here are the time-course results (with a graph below on the proportion of Aussies professing no religious beliefs), and they’re heartening. As you can see, pure creationism has dropped from about 10% in 1985 to 4% in 2017, theistic evolution has steadily dropped from 50% to 25%, and non-theistic (naturalistic) evolution has risen from 25% to 62%. (“Uncertain” people have fluctuated between 3% and 15%.)

This decrease in the belief of goddy forms of evolution has accompanied a rise in the proportion of Aussies professing no religious belief: the census data show an increase from about 13% in 1985 to 30% in 2017.  All of these changes are statistically significant except for the ‘uncertain’ class.

(From paper) a Percentage of each year’s students choosing each of four options in relation to human evolution: (1) creation by god within the last 10,000 years (green); (2) evolution over millions of years with the whole process guided by god (blue); (3) evolution over millions of years but god had no part in this process (red); (4) no idea or no opinion (yellow). Figures include lines of best fit from linear and quadratic regressions with 95% confidence intervals. The level of statistical significance (p) and the explained variance (R2) are listed below in parentheses. Options 1 and 2 show a statistically significant decrease over this period (1: p < 0.001, R2 = 0.48; 2: p < 0.001, R2 = 0.86). Option 3 shows a statistically significant increase (p < 0.001, R2 = 0.83). There was no significant change in the percentage of students choosing Option 4 (p = 0.3). b The percentage of the wider Australian public declaring in the national census between the years 1986 and 2011 that they had no religion. This percentage is increasing in time (p < 0.001, R2 = 0.96). This percentage also significantly predicts the percentage of First Year Biology students at UNSW that chose Option 3 (non-theist evolution) in our survey over the same time period (p < 0.001, R2 = 0.91). Published data obtained from Anon (Anon 2013)

The trend of increasing secularism in Australia has been going on for roughly 5 decades. Here are forty years of data on the proportion of nonreligious Aussies taken from Wikipedia: (as is usual in the West, women are more religious than men):

Males and females who claim no religion on the census from 1971 to 2011

Here are 35 years of data from the Gallup poll of U.S. adults asking basically the same question. As you can see, the results are very different. Biblical young-Earth creationism and theistic evolutionism now tie with 38% of Americans in each class, with perhaps a slight decrease in the young-earth creation class. Naturalistic evolution is still low—19%—but has increased fairly steadily from 9% in 1982.  This may reflect a long-term trend as well, perhaps accompanying the long-term rise in Americans who are “nones”, professing no formal affiliation with a church. (That’s not equivalent to having a lack of religious belief, though.)

In both the U.S. and Australian cases, I don’t think the coincidence of an increase in acceptance of naturalistic evolution with an increase in secularism is a coincidence. As I said in Kent, as elsewhere, there’s not really a good reason to be a creationist if you’re not religion. (As I put it, “You can have religion without creationism, but you can’t have creationism without religion.”) Now you can still dislike evolution as a secularist if you’re also a human exceptionalist, but it’s telling that every creationist I’ve met in America, and every creationist organization, is fundamentally religious. That’s because nearly all religions require human exceptionalism.

The authors of the new paper, Michael Archer et al., also attribute the difference between U.S. and Australian data to a difference in religiosity, but somewhat the religion by saying this reflects a “difference in cultural backgrounds of the two countries.” Yes, religion is part of culture, but the authors seem a bit reluctant to explicitly say that, going instead back in history (which may well explain an initial difference in religiosity):

Perhaps part of the reason acceptance of non-theistic evolution is growing more rapidly in Australia than in the USA may be the different cultural backgrounds of the two countries. Europeans who first moved to North America were in the main deeply religious, primarily Protestants. In contrast, most Europeans who moved to Australia, some as ‘guests’ of Her Majesty’s prison system, were far less concerned with religious matters. As Karskens (1997) notes in relation to the late 1700s early 1800s, “Most sources confirm that Sydney’s people did not attend the established church. Orders commanding them to observe the Sabbath by avoiding both work and carousing were routinely ignored, so that clergymen were invariably scandalized by the empty churches and the full taverns on Sundays…Over 40 per cent of the convicts said they had no religious affiliation whatsoever. Compulsory attendance at divine worship…was regarded as part of their punishment.” Making more or less the same point, the first Christian cleric in Australia (Rev. Richard Johnson) who sailed with the First Fleet had an incredibly hard time trying to raise funds to build any form of a church. So much was this the case that he ended up paying for the building out of his own wages. The church was finally built in 1794 and shortly after completion, was deliberately burnt down. After losing his church and much of his own income Rev. Johnson filed for a leave of absence to visit England. He never returned to Australia. In 1805 Johnson appears on a list of officers as “On leave in England, no successor or second clergyman appointed” (Macintosh 1978).

Well, yes, the starting points may have differed between the two countries, but I gather that Australia in general is simply less interested in religion than is the U.S., and not all Australians descend from convicts. Regardless, the American data show how backwards we are compared to other Western countries (we’re the lowest in accepting evolution and among the highest in religiosity). Despite the desperate attempts of Americans—I’m talking about you, Jesuit priest in Kent, Connecticut!—to pretend that religion and acceptance of evolution are compatible, what else but incompatibility can explain the concomitant increase in acceptance of evolution as religion wanes in country after country?

h/t: Woody (and several other readers)

____________

Archer, M., A. G. B. Poore, A. M. Horn, H. Bates, S. Bonser, M. Hunt, J. Russell, N. P. Archer, D. J. Bye, and E. J. Kehoe. 2018. Thirty two years of continuous assessment reveal first year university biology students in Australia are rapidly abandoning beliefs in theistic involvement in human origins. Evolution: Education and Outreach 11:12.

 

Here we go again: a Templeton-sponsored conference designed to “expand” evolutionary biology

August 21, 2018 • 9:00 am

When I was sent this announcement of a conference on evolution at Cambridge University next year (click on screenshots), and when I read the program and saw the speakers (links at third screenshot), I smelled a RAT (abbreviation for “rubbish and Templeton”), but I didn’t know for sure that the John Templeton Foundation was one of the sponsors till I clicked on the page given in the fourth screenshot.

And this page gives the aims of the conference and the names of the speakers (I know of only one of them, but of course I’ve been out of active science for a while):

This is the same tired old panoply of buzzwords that we’ve seen before: developmental bias (true in some sense, but we haven’t the slightest idea how important it is in evolution), developmental plasticity (a substitute for natural selection and mutation in initiating adaptive evolution, but again with virtually no evidence to support it) and “extra-genetic inheritance”—read “epigenetics”—another completely unevidenced factor in adaptive evolutionary change. What we have in this program, then, is a group of overly ambitious people, instantiated in the “Extended Evolutionary Synthesis” site (see below), who keep writing papers and having meetings touting their unevidenced theories, hoping that by sheer force of verbiage they’ll hijack modern evolutionary theory.

As for “balance”, there isn’t any in this conference: I see no critics of these buzz-topics on the program (they could, for example, have chosen the eminent critics Brian Charlesworth or Doug Futuyma, whose papers I cite below).

The odor of the Templeton Rat—remember that the nefarious rat in the book Charlotte’s Web was named “Templeton”!)—led me to this, which is exactly what I expected. Templeton is deeply invested, both programatically and financially, in overturning the modern view of evolution, perhaps because they think the “extended synthesis” will somehow promote spirituality or at least do down traditional evolutionary biology:

What is the Extended Evolutionary Synthesis (EES)? You can read about it here, but it’s tendentious: designed explicitly to overturn long-standing aspects of what we call “neo-Darwinism”. Here’s what it’s designed to overthrow (these criticisms are followed by the “replacement theories” of the EES on the page:

We already know that new variation can arise through horizontal gene transfer as well as mutation, but that’s not part of the EES, whose proponents want to include epigenetic variation induced by the environment that mysteriously becomes heritable and a part of the DNA. Then—presto—adaptive evolution occurs! That there is not a lick of evidence for his idea hasn’t fazed its supporters at all. As I’ve stressed before, there is no evidence for any epigenetic changes lasting more than a couple of generations, and virtually no evidence that such changes have been part of adaptive evolutionary change. And to “natural selection”, which has been demonstrated time and time again, EES proponents want to add another arcane mechanism in which nonadaptive developmental plasticity somehow becomes incorporated into the genome as an adaptive phenomenon. Despite thousands of pages written about that, there are no convincing examples, and therefore NO evidence that such plasticity has played an “important” role in evolution.

I’ve leveled my criticisms at these “revolutionary” ideas time and time again (see here, for instance), but you can find them best incorporated in two recent papers (links free):

Charlesworth, D., N. H. Barton, and B. Charlesworth. 2017. The sources of adaptive variation. Proceedings of the Royal Society B: Biological Sciences 284.DOI: 10.1098/rspb.2016.2864 (see also my take on this)

Futuyma, D. J. 2015. Can modern evolutionary theory explain macroevolution?  Pp. 29-85 in E. a. N. G. Serelli, ed. Macroevolution: Explanation, Interpretation, and Evidence. Springer, Switzerland.

And here’s who funds the EES. Yep, it’s mostly Templeton again, with a consortium of decent universities all too ready to take filthy lucre. Fifty-one scientists have their hands in the till:

More aims of the EES:

The EES represents a new way of thinking about evolution, with its own assumptions, structure and predictions. It sets out to provide a coherent conceptual framework capable of inspiring novel research in evolutionary biology and adjacent fields.

We aim to:

  • Demonstrate the explanatory potential of EES thinking
  • Conduct critical empirical tests of key EES predictions
  • Devise novel conceptual and formal mathematical theory
  • Promote awareness of the role of conceptual frameworks in science and encourage pluralism

Our research will:

  • Provide definitive evaluations of the significance of hotly contested processes in evolution (e.g. niche construction, non-genetic inheritance)
  • Clarify the evolutionary importance of individual responses to the environment (plasticity)
  • Devise new theoretical approaches for complex genotype-to-phenotype relations
  • Establish to what extent developmental processes explain long-term trends, parallel evolution, biological diversity and evolvability

Note that the aims are often to “demonstrate” something rather than test it, and, indeed, this is my big objection to the EES program. While it’s possible that epigenetic inheritance, developmental plasticity as an initiator of adaptive evolutionary change, and other ideas have played some role in evolution, there is no evidence that they’re important. Indeed, this EES business has been promoted for years, and there’s little to show for it—certainly no widely accepted expansion of modern evolutionary theory except for the expansion of gaseous words produced by EES promoters. It’s a melange of theories without evidence—something that, indeed, the EES website admits:

What do people think of the EES?

The EES has been met with both enthusiasm and skepticism. The majority of responses to the EES research program are extremely supportive, but there are of course those who claim that the EES is not going to do any good. The skepticism is to some extent warranted, as the EES has yet to prove itself a vehicle for productive research within evolutionary biology. That is why this project sets out to put EES predictions to the test with a dedicated research program. The project aims to show that, precisely because it is spelled out in a disciplined way, the EES can stimulate novel questions, devise critical tests, open up new lines of enquiry, and provide insights that are unlikely under traditional perspectives.

Well, you know, these ideas have been floating around for about fifteen years or more, and if the EES hasn’t proven itself productive, except in getting dosh to scientists and yielding an endless stream of speculative papers, maybe it’s time to reassess its value. But as long as Templeton keeps handing out millions of dollars to promote these ideas, there will be a never-ending stream of grant-hungry scientists with their hands out, eager to advance their careers by promoting the Templeton agenda. To my mind, this is the biggest example of misguided careerism I’ve seen in evolutionary biology over my lifetime.

Readers’ wildlife photographs (and videos)

August 12, 2018 • 7:30 am

Reader Olen Rambow sent a video demonstrating = convergent evolution: a “hummingbird moth”, one of several species that hovers before flowers like hummingbirds and sucks nectar from them with a large proboscis. This one is probably the white-lined sphinx moth, Hyles lineata. His notes are indented:

While visiting Santa Fe, NM, I ran across a moth that I first mistook for a hummingbird. I was fooled by its flight patterns and wing movements as much as its body shape (especially when viewed from the side). I’d never seen such moths before, but I’ve looked them up and now see that there is such a thing as a “hummingbird moth.” According to Wikipedia, they are an “example of convergent evolution.”

There are also hummingbirds in Santa Fe, often feeding alongside the moths, and this makes me wonder whether the resemblance might actually be an example of mimicry, since other birds might be less inclined to try to eat a moth if they mistake it for a hummingbird. Mimicry and convergent evolution are two separate things, right? Could this be an example of both? I.e., the body shape, flight patterns, etc., give the moths all the same benefits that hummingbirds enjoy while also protecting them from predators by making them look like hummingbirds?

I suspect this isn’t a case of mimicry, as the birds have keen eyes and, although hummers can eat some small insects like gnats, would probably find a moth too large to eat. The birds are, by and large, nectar-sippers.

From Tim Anderson in Australia, a picture he calls “Fountains in the sky.” His notes:

A pic of the Southern part of the Milky Way, showing the Carina Nebula at the bottom, the Southern Cross and the Coalsack, and the Pointers. Taken with a Canon 80D and a Samsung 14mm lens.

A field-trip course in England on Darwin and evolution

August 9, 2018 • 9:30 am

Every year my friend Andrew Berry, a lecturer and student advisor at Harvard, teaches a summer course at Oxford for Harvard undergrads. Its theme is Darwin and evolution, and the best part is that since the course takes place in DarwinLand, he can take the students to various historical sites and show them the science and history behind the Great Idea. I went to Down House, Darwin’s adult home, with Andrew’s course one year, and we were given a tour by none other than Janet Browne, historian of science and author of the wonderful two-volume biography of Darwin (see here and here) that I consider the best account of his life and work. Janet still takes the students to Darwin’s home, and you can see her in the penultimate photo.

Every year Andrew puts up a photo website of that summer’s course for the delectation of the students, and I thought I’d share some of them with you so you could see what the course covers. Go here to see all of the pictures. Andrew has kindly furnished captions for them giving the historical background, and his descriptions are indented. You can enlarge all the photos by clicking on them (twice if you want to eliminate the text).

The program runs for 6 weeks in Queen’s College, Oxford. It is a mix of history of science (the development of evolutionary thinking) and of science (current thinking in evolution).  This photo comes from a previous year during a more typical English summer.  The current heatwave (yes, in England) has scorched the college lawns.
Most of the students (there are 17 in this year’s class) spend the two weeks prior to the program in London, interning at the Royal Botanic Gardens, Kew, on a history of science project dedicated to creating an online archive of the writings of Joseph Dalton Hooker, Victorian botanist, director of Kew, and Darwin confidante.  Pictured is Kew’s extraordinary Palm House (1848), commissioned by Hooker’s father, the previous director, and designed by Decimus Burton.
Hooker traveled on James Clark Ross’s Erebus & Terror expedition to Antartica (1839-43) where his skills as a botanical illustrated were challenged by the local fauna.
Hooker undertook another major expedition, to the E Himalaya (1847-51).  Here is a sample of his exquisite pen-and-water color sketches of the landscape.  Among these is numbered the first known view by a European of Mt. Everest.  http://blogs.nature.com/news/2011/02/first_sketch_of_everest_credit.html
Hooker’s ticket, as pall bearer, to Darwin’s funeral, 1882.
Cambridge.  Darwin was a student here (after dropping out of his medical studies at Edinburgh University), and came back here after returning from the Beagle voyage so that he could start processing the specimens he had brought back with him.
Darwin’s undergraduate room in Christ’s College, Cambridge.  This is where he lived when he was the same age as my students.
In the archives of Christ’s College is a wealth of Darwin-related material, including illustrated letters celebrating his undergraduate beetle-hunting excitements.
Christ’s College boasts a statue of the young Charles Darwin (an attempt to re-create Darwin as he was when he was at Christ’s).  He is, as such, inevitably a selfie target.
Behind the scenes in the Cambridge Zoology Museum: bird of paradise specimens collected by Alfred Russel Wallace in the course of his Malay Archipelago journey
The commonplace book of Erasmus Darwin, physician, inventor, poet, evolutionist, and grandfather of Charles Darwin.  Erasmus gave us the best ever synopsis of evolution (from his Temple of Nature, 1803):
Organic life beneath the shoreless waves
Was born and nurs’d in ocean’s pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.
Erasmus Darwin lived in Lichfield’s cathedral “close” (ie the community associated with the great church).  He had to be careful in the use of his evolutionary motto, E Conchis Omnia (from shells, everything), for fear of offending his ecclesiastical neighbors
Linnean Society, London, with archivist Isabelle Charmantier.  It was at a meeting here, on 1 July 1858, that the theory of evolution by natural selection was unveiled, though neither of the paper’s authors, Darwin and Wallace, was present.
The Linnean Society possesses the papers and collections of Linneaus himself, the Swedish father of taxonomy.  Here are some of his early notes as he explores ways to categorize and organize nature.
1735: the first edition of Linneaus’s great work, Systema Naturae.  Here he has already grouped humans with primates (“Simia”), though he mistakenly includes sloths (Bradypus) in the group as well.
Revising life.  In later editions of Systema Naturae, Linnaeus had blank pages bound between each printed page and used these to make revisions for subsequent editions.  In his tiny, cramped hand-writing, then we are seeing Linnaeus in the process of revising the organization of living things.
Linnaeus’s specimens.  By definition, most of Linnaeus’s specimens are type specimens — ie the key specimen from which a species was originally described.
Linnaeus’s Lapland expedition note book.  Linnaeus’s reputation was established by his journey into the northern wilds of Scandinavia.  His field note book contains of wealth of biological, geographical and anthropological observation.  His drawing skills, however, left something to be desired.  This is a charming illustration of the preferred local way of carrying canoes.
The room in which Darwin was born, 12 Feb 1809.
Shrewsbury, where Darwin was born and grew up.  The family house, The Mount, built by his father Robert Darwin on a small rise overlooking the town, is now a district tax office, but they generously allow pre-arranged visits by small groups.
(Old) Shrewsbury School.  Darwin attended the local private high school (as a boarder even though the school was less than a mile from his home).  The school has since moved out of the centre of town, and the Darwin’s school building is today the town library.  Darwin’s retrospective assessment of his experience there was not especially positive: “Nothing could have been worse for the development of my mind than Dr. Butler’s school, as it was strictly classical, nothing else being taught, except a little ancient geography and history. The school as a means of education to me was simply a blank.”

Update: the next picture is a close-up of the statue taken by reader Al Lee and just sent along:

In the Shrewsbury School library: Presentation copy of the Origin of Species given to Darwin’s prominent opponent, Richard Owen.  Note that it is dated prior to the publication of the book (24 Nov 1859).
In Darwin’s geological footsteps.  After finishing his undergraduate degree at Cambridge, Darwin traveled to N. Wales with Adam Sedgwick, his geology professor.  Sedgwick was trying to make sense of the sequence of rocks that would later become formalized as the geological column.  In particular he was interested in finding Old Red Sandstone (from the Devonian) on his travels.  This however proved elusive. Darwin visited Cwm Idwal in Snowdonia (ie the mountainous area in the NW of Wales) twice.  First, in 1831, as part of his Sedgwick expedition.  He attempted to interpret the landscape but was defeated by the region’s complexity and his own lack of experience.  He came back after the voyage of the Beagle  when he had read Louis Agassiz’s theory of Ice Ages.  He recognized that the best place he could go to to see for himself whether or not these new fangled ideas were sound was Cwm Idwal.  He was convinced: “a house burnt down by fire does not tell its story more plainly than did this valley.”
Learning to read the landscape with our guide, Michael Roberts, geologist, historian, and vicar.
“Darwin’s Boulders” beside the lake in Cwm Idwal:
Hiking Y Garn, the mountain overlooking Cwm Idwal.
Castel Dinas Bran, above Llangollen.  Another site visited by Darwin and Sedgwick in pursuit of recognizably Devonian deposits.  The hill is crowned with the picturesque ruins of a 13th century Welsh fort.
Fossil hunting.
Oxford University Natural History Museum, June 1860: site of the famous spat between T  H Huxley and Samuel Wilberforce, Bishop of Oxford.  The exchange is probably somewhat apocryphal, but it has entered popular consciousness as a canonical science vs. religion moment.  As recounted by historian Frank Sulloway, “Following a lengthy, pro-Darwinian paper, Samuel Wilberforce, the slickly eloquent bishop of Oxford, began a half-hour-long attack on Darwinian theory. With glib lines like “Is it credible that a turnip strives to become a man?,” Wilberforce’s speech met with peals of sympathetic laughter, and his rhetoric hit home. Finally he turned to Huxley, who was seated near him on the speaker’s platform, and asked him whether it was on his grandfather’s or grandmother’s side that he claimed descent from an ape.”  Huxley’s supposed response: “[Asked] if I would rather have a miserable ape for a grandfather or a man highly endowed by nature and possessed of great means and influence, and yet who employs those faculties for the mere purpose of introducing ridicule into a grave scientific discussion — I unhesitatingly affirm my preference for the ape.”
Natural History Museum, London, archive.  A drawing by A R Wallace of an Amazonian fish.  That this picture still exists is remarkable.  This was part of the set of materials — specimens, notes, drawings, living animals — that Wallace had with him as he headed back to the UK after four years in the Amazon.  His ship caught fire in the middle of the Atlantic, and Wallace and the crew had to abandon ship precipitously.  Wallace had time to grab one small case of materials from his desk, and this drawing was in it.  It was ten days before Wallace and the crew were rescued.
Darwin (statue) and Wallace (portrait): side by side (OK, with a big gap between them) at the Natural History Museum.
[Photo from previous year, as we have yet to go to Down House this year].  Down House, Kent, where Darwin lived for more than half of his life and where he penned the Origin of Species, the Descent of Man, and more.
[Photo from previous year, as we have yet to go to Down House this year].  Darwin’s “thinking path”, the Sand Walk, where he would stroll and ponder.  I live in hope that my students will have correspondingly significant insights as they walk along the path, but it’s yet to happen. Here they are accompanied by Janet Browne, Darwin scholar and biographer.
Finally, Andrew sent me this photo (taken some years ago when I was a lot pudgier!), also at Down House:
Isn’t that a lovely course? I’d love to take the whole thing, but time prohibits that. Many thanks to Andrew for the photos and captions. I suspect this is the inspiration for the “Jumping at Down House” photo above.