Archive for the ‘Evolution’ Category

[Review] 99% Ape: How Evolution Adds Up.

June 6, 2010 1 comment

The following review first appeared in Journal of the History of Biology (2009).

To historians, textbooks can be useful data. Because of their very nature that can act as time capsules for “consensus science” during the period of their publication: cutting-edge science is usually omitted and students are usually only exposed to what is accepted by the majority of the scientific community. This is particularly true of textbooks aimed at secondary-level students. Yet textbooks – due to their pedagogical role – never fully disentangle themselves with the socio-political milieu from which they emerge. A classic example of this is George William Hunter’s Civic Biology (1914) which – along with the accepted science of the day – discussed eugenics, the perceived negative implications of “parasitic” families, and the hoped for future improvement of the human race. Textbooks, in short, can be more than just collections of scientific facts and theories; they are also embedded (and can function) within a socio-political matrix. I will return to this issue presently.

The work under review is the textbook for an entry-level Open University (UK) course titled Darwin and Evolution and as such is aimed at readers with no previous background in the biological sciences. As such, it offers an entry into the current state of evolutionary biology and sacrifices breadth for depth. Throughout the reader is presented with the evidence for evolution as fact (change over time within populations in both the neontological and paleontological realms) and as pathway (hypotheses about what changes into what through deep time). In addition various mechanisms for evolution are briefly discussed, with pride of place being given to Charles Darwin’s two mechanisms of natural and sexual selection. The examples will be familiar to many readers: Galapagos finches, East African cichlids, Hawaiian picture wing flies, the evolution of the Human Immunodeficiency Virus (HIV) from simian viruses, the transition to land, the evolution of birds and feathered dinosaurs, the evolution of whales, industrial melanism in peppered moths, and of course, human evolution. All are covered relatively briefly using clear text and often stunning illustrations.

Throughout the work genetic and morphological studies unite to offer explanations of organic diversity. Data from fossils are united with genetic studies (both phylogenetic and within the field of evolutionary developmental biology) to present our current understanding of a particular phenomenon. Often these investigations are put with an historical context. A good example of this is the chapter devoted to Darwin’s finches. Beginning with an account of Darwin’s own engagement with the group (and after tipping the hat to the pioneering work of David Lack) the chapter discusses the long-term studies of Peter and Rosemary Grant before culminating in a brief discussion of how the proteins calmodulin (CaM) and bone-modulating protein 4 (bmp4) control beak size and shape, illuminating how changes in the activation of genes controlling the production of these proteins could account for aspects of speciation within Geospiza. These findings are then integrated into a discussion of the geological and environmental history of the Galapagos archipelago. All of this occurs in eleven pages with twelve figures.

Historians of evolutionary biology are not likely to learn much new from this work and its value will be to us as teachers, providing as it does a brief and visually appealing introduction to modern evolutionary biology, one which can be recommended to students with little or no background in the sciences. That said the seven co-authors, all biologists, work hard to include historical information within the individual chapters. The work is richly illustrated with many images that historians will recognize and quotes abound from Darwin’s notebooks, Origin, and the Journal of Researches. Yet Darwin is not the only historical figure one encounters – Thomas Henry Huxley, William Paley, Samuel Wilberforce, and Louis Agassiz are (somewhat predictably) mentioned. There are however some surprises. The chapter on whale evolution introduces the reader to the relatively little known anatomist, William H. Flower, who in 1883 proposed – based on multiple lines of evidence – that whales evolved from artiodactyls. This idea received little support until the late 1980’s when new fossil finds and genetic studies overthrew the prevailing view that whales were related to a carnivorous group known as mesonychids. In time it has become clear that the closest living relative to whales are in fact hippopotami. The book commemorates Flower’s bold claim with a full-page picture and an extensive quotation that is worth repeating here (in an abbreviated form):

“We may conclude by picturing to ourselves some primitive generalized, marsh-haunting animals with scanty covering of hair like the modern hippopotamus, but with broad swimming tails and short limbs, omnivorous in their mode of feeding … gradually becoming more and more adapted to fill the void place ready for them on the aquatic side of the borderland on which they dwelt, and so by degrees being modified into dolphin-like creatures inhabiting lakes and rivers and ultimately finding their way into the ocean.” (p. 93).

As I mentioned above, textbooks function within a socio-political matrix. Here in the United States that matrix is distinguished by the fact that over 50% of the population apparently believes that “the development of life was guided by intelligent design” (Zogby Poll, June 2009) and while traditionally an American problem, such anti-evolutionism has manifested itself in Europe and Australia. Chapter 18 distinguishes the “science of evolution” from the non-science of creationism and rightly identifies the modern Intelligent Design (ID) movement as a manifestation of the latter. Indeed, much of the evidence discussed in 99% Ape is precisely that dismissed by proponents of ID (such as Jonathan Wells) as flawed “icons of evolution”. Perusal of this book will show how strong the evidence for evolution (as fact, pathway & mechanism) is. Noting that there are no constitutional barriers (as there are in the US) to the teaching of creationism in British schools, the authors implicitly set their volume as a bulwark against future creationist incursions. For all of us – whether British or not – the book can serve as a primer of forceful examples to use whenever one needs to illustrate the evidence for evolution to a skeptical audience.

Jonathan Silverton, ed., “99% Ape: How Evolution Adds Up” (London, Natural History Museum, 2008; Chicago, University of Chicago Press, 2009), 224 pp., £14.99, $26.00 (paper).

[Review] The Evolution-Creation Struggle

June 3, 2010 Comments off

51J86J7T0DL._SL160_.jpg[The following appeared in Nature Reviews Genetics in 2005 under the title "The Secular Religion of Evolution(ism)". As such it appeared before the tendency of New Atheists to throw out the epithet  "appeaser" or "accomodationist" (and their general vehement detestation of Ruse). While in a different venue (or indeed five years later), I may have written a different review of the book, here is what I wrote back then.]

As an undergraduate in Ireland in the mid-80’s I ran across a copy of Ashley Montagu’s book Science and Creationism. Frankly, I felt that I was reading some kind of parody – could there actually be people in a technologically literate country like the United States who denied both the fact of evolution and the hypothesis that natural selection was a mechanism for such change? Such opposition was not an issue in Ireland and I could not see why it should be in America. Subsequent experience has taught me that this is sadly the case, and indeed that anti-evolutionists often have understandable reasons for their opposition to Darwinian evolution.

The Montagu volume contained an article by the philosopher and historian Michael Ruse describing his experiences during the 1981 Arkansas “Scopes II” trial in which he provided Judge William Overton with a somewhat controversial definition of “science” and thus the basis of the decision to ban “creation science” from Arkansas public schools. This decision, along with the 1987 Supreme Court ruling in Edwards v Aguilard, marked a sea-change for the anti-evolution movement in America. As a result, creationism itself was forced to evolve and indeed, the resurgence of intelligent design (ID) is a clear indication that anti-evolutionism has not died in the United States. With ongoing creationist action at the state and local level in many states in America, the struggle between supporters of evolution and creation is not likely to disappear soon, and indeed ID appears to be making some inroads into Europe.

In this relatively short and readable book, The Evolution-Creation Struggle, Ruse sets out his vision of this ongoing struggle between evolution and creation. Following a broad historical narrative beginning with the Enlightenment and discussing the development of evolutionary biology as a fully-fledged professional science, Ruse is careful to distinguish between evolution and evolutionism. The former is a professionalized field within biology that deals with facts and observations, the latter, a secular religion of evolutionary philosophical naturalism that smuggles values into evolution. Ruse notes that evolutionism is practiced – if not preached – by many of the most skillful popularizers of evolutionary biology; Richard Dawkins, E.O. Wilson, William D. Hamilton, Jerry Coyne, and William Provine are all offered as exemplars. These supporters of evolutionism, Ruse claims, exhibit a worldview that is ultimately optimistic and supports progress. In fact, he sees such individuals as essentially post-millennial, that is believing that humans can work towards a better future. This is in opposition to pre-millennialists (including advocates of creationism and intelligent design) who, believing in Christian providentialism, hold that human action alone cannot and will not make the world a better place. Ruse thus shifts the “struggle” from (the traditionally accepted) one of evolution versus creation to one of differing visions of the future of humanity.

It would be tempting – and easy – to misread Ruse as saying that evolution is a religion, and I expect creationists will, if past history is any guide, misquote portions of this work. Ruse clearly states that evolution is a mature, professional science exhibiting “[p]rediction, consilience, consistency, and fertility”. Indeed, Ruse denies these very characteristics to intelligent design, stating “we find no empirical or conceptual reason whatsoever to think of intelligent design theory as genuine science … [T]here are no results. And there are no new predictions leading to new and unexpected discoveries”. On this point, I wholeheartedly agree with Ruse.

He also believes that Darwinism – or any other form of evolution – does not entail the secular theology of evolutionism, and that Christianity itself does not entail any form of anti-evolutionism. In short, one can be a Darwinian and a Christian – an observation backed up in the writings of theologian John F. Haught or biologist Kenneth R. Miller. Thus, Ruse sees it as a fatal flaw for supporters of evolution not to realize that there are deeply religious individuals who support evolution yet dismiss evolutionism, and he states that evolutionists need to “start thinking about working together … rather than apart” with such individuals .

Ruse’s point is clear; “Those of us who love science must do more than simply restate our positions or criticize the opposition. We must understand our own assumptions and, equally, find out why others have (often) legitimate concerns. This is not a plea for weak-kneed compromise but a more informed and self-aware approach to the issues. First understanding, and then some strategic moves”. The evolution-creation struggle has generated more heat than light in the quarter century since the Arkansas trial, and it shows no sign of letting up. Whether Ruse’s analysis is ultimately accurate or not, he is correct in claiming that, as educators and evolutionists, we need to be aware of the potential perils of evolutionism.

Michael Ruse, The Evolution-Creation Struggle, Harvard University Press, 2005

Footprints of nonsentient design

May 6, 2010 4 comments

John Avise has a paper upcoming in PNAS. Here’s part of the abstract:

Here, I highlight several outlandish features of the human genome that defy notions of ID by a caring cognitive agent. These range from de novo mutational glitches that collectively kill or maim countless individuals (including embryos and fetuses) to pervasive architectural flaws (including pseudogenes, parasitic mobile elements, and needlessly baroque regulatory pathways) that are endogenous in every human genome. Gross imperfection at the molecular level presents a conundrum for the traditional paradigms of natural theology as well as for recent assertions of ID, but it is consistent with the notion of nonsentient contrivance by evolutionary forces.  

Article is here. doi: 10.1073/pnas.0914609107  

Origins: Natural Selection

February 7, 2010 Comments off

Monday’s class is an introduction to the logic of natural selection. As I usually do when presenting selection, I follow Ernst Mayr’s formulation of a series of facts and inferences from those facts. I then deal with some of the consequences of the idea and the prevalent misconceptions about evolution through natural selection. Some of the slides are going to be anything but self-evident, I’m afraid.

The next three lectures will be focused on the history of American anti-evolutionism and I will, of course, post those slides (starting on Wednesday).

Meanwhile in Chicago …

November 1, 2009 Comments off

There’s a big Darwin meeting going on in Chicago this weekend with concurrent science and HPS sessions. I was originally going to attend but work got in the way. PZ Myers has been live blogging the science talks by Dick Lewontin, Ron Numbers, Mark Hauser, Doug Futyuma, the Grants, Douglas Schemske, Paul Sereno, Frederick Cohan, Jerry Coyne, Eric Lander, Philip Ward, David Jablonski, David Kingsley, Neil Shubin, and Hopi Hoekstra.

He also stumbled into Michael Ruse’s talk on “Is Darwinism past its ‘sell by’ date? The challenge of evo-devo” – I suspect this is the talk Ruse gave here at ASU in February (transcript available) – and one by philosopher Bill Wimsatt that left him a little confused. Bill often has that effect of folks.

Update: I thought there was a verb, to Wimsatt. I was wrong.

Systematics and Biogeography

September 10, 2009 Comments off

By way of Wilkins I see that Nelson & Platnick’s Systematics and Biogeography (1981) is now freely available online as a PDF. Wander here … and pick up a copy of John’s book (Species) while you are at it.

Therizinosaurs near Tempe

September 2, 2009 4 comments


The Therizinosaur – Mystery of the Sickle-Claw Dinosaur exhibit that has been in the Museum of Northern Arizona for the past few years is coming to the Arizona Natural History Museum on October 3rd. Excellent stuff. Who wouldn’t want to see the skeleton of a 93 million year old, 13-foot-tall, one-ton, sickle-clawed, feathered dinosaur? This won’t be as spectacular as the recent feathered dinosaurs exhibit (see here and here), but still good nonetheless.

You can read more on Therizinosaurs here and here.

How to make a flagellum in a test-tube.

August 8, 2009 2 comments


So looks like pili and flagella can appear without a designer’s action. No doubt the ID brigade will either argue that the change doesn’t represent an increase in information or that it represents front-loading by the Designer That Shall Not Be Named.

[Geobacter] sulfurreducens bacteria were cultured on a graphite electrode under a 400 mV applied bias. The goal was to force the bacteria to adapt to conditions inside the MFC [microbial fuel cell] with the hope that they would evolve greater functionality in the process. Several colonies were isolated after five months in the MFC environment and re-cultured under normal conditions. When placed in an MFC cell, the specially cultured bacteria grew much more rapidly—current saturated after 50 hours as opposed to 400 hours—and they provided twice the current density of normally cultured bacteria.

Analysis of the enhanced bacteria showed that there were two primary adaptions. First, pili, fine, thread-like structures that connect neighboring cells, dramatically increased in the new bacteria. These structures are thought to be responsible for electronic conduction in bacterial films. Also, unlike their precursors, the enhanced bacteria all had flagella that allowed both motility and enhanced attachment to anode surfaces. It is unclear which adaptation is primarily responsible for the enhanced performance.

From here with a hat-tip to RBH.

Reference: Biosensors and Bioelectronics DOI:10.1016/j.bios.2009.05.004

Image: G. sulfurreducens biofilm (source)

Carnival of Evolution #14 now online

August 1, 2009 Comments off

The Carnival of Evolution is up to incarnation number 14 and this month is to be found over at Steve Matheson’s place, Quintessence of Dust .

Darwinius: The Book of the Movie of the Fossil

July 4, 2009 Comments off


Readers probably remember Darwinius masillae (“Ida”) the the beautifully preserved adapiform primate hyped as “the missing link” (the original paper is here). What we saw in May was media-driven science with a book, movie & website. As Jerry Coyne notes, “[i]n the end, it was the bloggers like Brian Switek, and a few intrepid science journalists like Ann Gibbons, who put Ida in the correct perspective.” Jerry brings our attention to Ian Tattersall’s review of the book of the fossil, The Link by Colin Tudge & Josh Young. Tattersall isn’t very impressed:

Colin Tudge’s book is part of the media blitz; and, at the risk of damning it with faint praise, I have to say that it is much the best part. … Understandably, Ida herself doesn’t take up too much of the volume. Instead, most of what we find in its pages is an amiable, meandering and hugely repetitive stroll through the environments and faunas of the past 50 million years. Interspersed with passing references to Ida and some miscellaneous philosophizing.

Not much to look forward to here by the looks of things.

Evolution of house cats

June 13, 2009 Comments off

Scientific American has a nice piece by Carlos A. Driscoll, Juliet Clutton-Brock, Andrew C. Kitchener and Stephen J. O’Brien on the evolution of domestic cats. Juliet, Andrew and I have written on hybridization between Arctic wolves (Canis lupus arctos) and domestic dogs (see pdf here) and Andrew and I have been frequent collaborators on projects examining morphological variation in carnivores and other groups (see here). We’re currently finishing up a paper on morphological variation in European beavers (Castor fiber) and its implications for the reintroduction of the species to Scotland.

Evolutionary biology and the law

June 11, 2009 1 comment

For a number of years (2004-’09) I was the interdisciplinary officer for the Society for Evolutionary Analysis in Law (SEAL), a group of scholars who take seriously the implications that findings in evolutionary and behavioral biology may have for the law. The group has – however – not being without its detractors, one being Brian Leiter who has announced a paper (with philosopher Michael Weisberg) titled “Why evolutionary biology is (so far) irrelevant to legal regulation” to appear in Law and Philosophy later this year. As I have not, as yet, read the paper, suffice that I post the abstract here:

Evolutionary biology – or, more precisely, two (purported) applications of Darwin’s theory of evolution by natural selection, namely, evolutionary psychology and what has been called human behavioral biology – is on the cusp of becoming the new rage among legal scholars looking for interdisciplinary insights into the law. We argue that as the actual science stands today, evolutionary biology offers nothing to help with questions about legal regulation of behavior. Only systematic misrepresentations or lack of understanding of the relevant biology, together with far-reaching analytical and philosophical confusions, have led anyone to think otherwise. Evolutionary accounts are etiological accounts of how a trait evolved. We argue that an account of causal etiology could be relevant to law if (1) the account of causal etiology is scientifically well-confirmed, and (2) there is an explanation of how the well-confirmed etiology bears on questions of development (what we call the Environmental Gap Objection). We then show that the accounts of causal etiology that might be relevant are not remotely well-confirmed by scientific standards. We argue, in particular, that (a) evolutionary psychology is not entitled to assume selectionist accounts of human behaviors, (b) the assumptions necessary for the selectionist accounts to be true are not warranted by standard criteria for theory choice, and (c) only confusions about levels of explanation of human behavior create the appearance that understanding the biology of behavior is important. We also note that no response to the Environmental Gap Objection has been proffered. In the concluding section of the article, we turn directly to the work of Owen Jones, a leading proponent of the relevance of evolutionary biology to law, and show that he does not come to terms with any of the fundamental problems identified in this article.

Update: John Wilkins makes some thoughtful comments here.

Reading Origin

June 3, 2009 2 comments

51hAscB-KIL._SL160_.jpgA few months ago, I recommended David Quammen’s illustrated edition of Darwin’s Origin of Species. Now another edition has come to my attention: “The Annotated Origin: A Facsimile of the First Edition of On the Origin of Species edited by James T. Costa, a biologist at Western Carolina University.

This edition pairs a facsimile of the first edition of 1859 with annotations by Costa which provide elucidation of the text using both historical and modern information. It has been used both in Costa’s course on Origin at WCU and in Harvard’s Darwin Summer Course at Oxford. The annotations look very useful for clarifying the nature and structure of Darwin’s argument. A brief introduction, a coda, and biographical notes are added. All in all, this edition looks very useful for classroom use, though the $35 price tag is a little too high. Hopefully Belknap Harvard will produce a paperback edition.

A further edition, edited by historian Jim Endersby, is to appear at the end of this month. At $115 it is even more expensive, and I currently have no clue as to what scholarly apparatus is added.

Who needs males?

April 15, 2009 1 comment


Apparently Mycocepurus smithii doesn’t. It has become the first ant species to dispense completely with males. More details here.

(The picture above – from the Daily Mail story – is actually by Alex Wild but is unattributed)

The Superorganism

April 9, 2009 Comments off

I’m currently reading Hoelldobler & Wilson’s The Superorganism and just ran across this post by Alex Wild which claims that

the whole section of The Superorganism devoted to the evolutionary history of ants is muddy, incoherent, and entirely at odds with the increasingly clear picture emerging from modern studies of ant relationships.

Alex is inaugurating Scienceblogs’ new photoblog, Photo Synthesis, and will be guest-blogging for a month, so wander on over and check it out. His own blog is also worth a read and his photos (here and here) are excellent.


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