Dolphin whiskers and cetacean evolution

April 26, 2013 • 8:17 am

The journal Evolution and Education Outreach is a valuable resource to anyone interested in or teaching evolution. Fortunately, it’s just been made an open-access journal, so anyone can read it free online (link is here). While perusing the articles, I found one that I thought was really good for not only teaching students about macroevolution, but learning about one of its paradigmatic cases: the evolution of whales from their ancestors—small hoofed mammals.  The article, by Thewissen et al., is called “From land to water: the origin of whales, dolphins, and porpoises“, and you can download the pdf here.

Although the article is four years old, it’s not out of date and it’s easily accessible to non-scientists. I like it because it completely destroys the ID and claim notion that although there has been “microevolution” (minor changes in form within animal or plan lineages), we don’t see any cases of “macroevolution” (major transitions between “types” of animals or plants).  That notion is absolutely belied by the fossils, for we can see macroevolutionary transitions from fish to amphibians, amphibians to reptiles, reptiles to mammals, reptiles to birds, and so on.  And, of course, we have the macroevolutionary transition from our early ancestors—resembling (but not apeing)—modern chimps and gorillas, to modern humans.

I’ll let you read the article yourself, for it’s one piece on macroevolution that you should have under your belt. (If you want more, there’s Don Prothero’s wonderful book, Evolution: What the Fossils Say and Why It Matters, which describes many examples of evolution in the fossil record.) But there are two figures that I want to post just because they’re cool.

The first involves a vestigial trait in cetaceans (whales, dolphins, and porpoises) that is seen only in the embryological state: whiskers. Cetaceans evolved from single whiskered common ancestor that lived on land land: an artiodactyl, or even-toed ungulates). In the course of becoming marine, though, the lineages lost their whiskers.  Nevertheless, they develop briefly in the embryo and then disappear. What better evidence for common ancestry of whales and terrestrial mammals? Here’s a photo from the paper:

Dolphin whiskers

And here’s something close to the terrestrial ancestor of the whale, the unlikely candidate Indohyus, a small, cat-sized mammal with separate toes, each of which ended in a hoof.  It’s thought to be related to the common ancestor of cetaceans because of its thickened wall in the middle ear (limited to modern whales, dolphins and porpoises), its dense bones, which would suit it for living part-time in water (heavy bones make it easier to wade), and chemical analysis of its teeth, which show an oxygen 16:18 isotope ratio characteristic of animals who live in the water:

Picture 1
Thewissen et al. mention a video I’ve posted before, showing how a terrestrial artiodactyl might become aquatic. It’s the African mouse deer (Hyemoscus aquaticus also called the “water chevrotain”), which, though terrestrial, stays near water and swims, fully submerged, to escape from predators. This remarkable video shows how the evolution of aquatic behavior might have started:

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Thewissen, J. G. M., L. Cooper, J. George, and S. Bajpai. 2009. From land to water: the origin of whales, dolphins, and porpoises. Evolution: Education and Outreach 2:272-288.

Two profiles of Sam Harris

April 26, 2013 • 5:51 am

Several readers (thanks to all) have called my attention to two pieces about Sam Harris (free online) in the new Atlantic: an interview “What martial arts have to do with atheism,” and an article (another about Sam’s penchant for martial arts), ‘The atheist who strangled me“. The interviewer and the writer are Graeme Wood.

I knew that Sam was not only an advocate of gun ownership, but a practitioner of martial arts, but I didn’t know how avid he was about the latter. He’s apparently a diligent student—training three times a week—of Brazilian jiu-jitsu (BJJ), a lethal form of hand-to-hand combat that you can see on YouTube, and whose aim is to strangle the opponent or break his limbs.

I had thought that Sam’s motivation for owning guns and studying jiu jitsu was to protect himself in light of the many death threats his gotten after publishing two books attacking religion, but there’s also another motivation that I found interesting. This quote ends the “strangled” article:

A week later, Harris tutored me in his other passion: meditation. The introduction left me with an even greater sense of spiritual discomfort than the ass-kicking. And after 20 minutes of struggling to banish the voices in my head and clear my mind, I felt just as winded as I had at the Gracie Academy. The experience did, however, offer some insight into why Harris might crave a daily routine of silent reflection. He has, after all, chosen a life of wandering the Earth getting in unwinnable arguments with unyielding people. Perhaps this leaves him with an unusual need for peace, quiet, and answers.

“The sort of satisfaction one hopes to achieve in intellectual debate is always elusive,” said Harris, referring to his public disputations with various professional Christian apologists. “I’ve had debates where it’s absolutely clear to me that my opponent has to tap out,” he told me. [JAC: “Tapping out” refers to practice bouts of BJJ in which you signal your helplessness to the opponent by tapping his body.] “They are wrong—just as demonstrably as you’re wrong when you’re being choked to death in a triangle choke.” (Which raises the possibility that, however calm and well-spoken Harris appears onstage with, say, Rick Warren, he may be silently imagining strangling the pastor into unconsciousness.) “It’s like they’ve turned into a zombie,” he continued. “You rarely get the satisfaction in intellectual life where the person who is wrong has to acknowledge and grow from the experience of having been self-deceived for so long.”

That’s true, but you do get the satisfaction of receiving letters—and Sam has gotten many—showing that your public debates have converted onlookers to your point of view.

If you want to see what BJJ looks like, here’s an example.  According to Sam, an expert in BJJ can “put you to sleep” in 6 to 10 seconds once he gets his hand on your neck:

Red panda gymnastics for Friday

April 26, 2013 • 4:51 am

The red panda (Ailurus fulgens, or “shining cat” in Latin) is a denizen of the same bamboo forests of China that harbor the giant panda (Ailuropoda melanoleuca, meaning “black and white cat-foot”). They also subsist largely on bamboo leaves, though they’re a bit more omnivorous than their larger relative. Although it’s called the “lesser panda”, and is sympatric with A. melanoleuca, red pandas aren’t that closely related: the red panda is in the family Ailuridae and superfamily Mustiloidea, along with otters, skunks, weasels and raccoons, while the giant panda is in the family Ursidae, along with other bears.

When I was in graduate school, it was still debated whether giant pandas were really closely related to bears, a question that was resolved using molecular analysis: immunological distance. The study, by Vince Sarich, was published in Nature in a paper with a wonderfully concise title: “The giant panda is a bear.” The phylogenetic position of red pandas was resolved in several later studies.

But enough of the biology lesson—let’s end a long week with a video of this delightful animal training for the next Olympics:

And for extra squee, some red panda babies from the Knoxville Zoo:

red panda babies

Dawkins named world’s top thinker

April 25, 2013 • 1:23 pm

No, it’s not Peter Hitchens or Terry Eagleton.  Nor is it Glenn Greenwald, R. Joseph Hoffmann, or any of the critics of New Atheism who fancy themselves far more sophisticated and, perhaps, influential than the New Atheists.  (We’ve all heard the hounds baying about the declining relevance and clout of all those “militant” athiests.)

No, according to a Prospect Magazine poll, the world’s top thinker, the person who was most intellectually influential over the last 12 months, was—Richard Dawkins.  And #3 was another vociferous atheist, Steven Pinker. In the #8 spot we find another godless person: Peter Higgs.

Here are the top ten, chosen by Prospect readers from a list of 65 people created by an elite panel from the U.S. and U.K. (links go to descriptions of the braniacs as well as the other 55 candidates):

1. Richard Dawkins
2. Ashraf Ghani
3. Steven Pinker
4. Ali Allawi
5. Paul Krugman
6. Slavoj Žižek
7. Amartya Sen
8. Peter Higgs
9. Mohamed ElBaradei
10.Daniel Kahneman

Other atheists known to me in the top 20 are Steven Weinberg (#11) and Oliver Sacks (#13).  That makes at least 25% atheists, twice the proportion of nonbelievers in the world as a whole. Maybe we should resurrect the term “brights.” (Only kidding!)

Prospect‘s analysis goes further:

Among the new entries at the top are Peter Higgs—whose inclusion is a sign of public excitement about the discoveries emerging from the world’s largest particle physics laboratory, Cern—and Slavoj Žižek, whose critique of global capitalism has gained more urgency in the wake of the financial crisis. The appearance of Steven Pinker and Daniel Kahneman, authors of two of the most successful recent “ideas books,” further demonstrates the public appetite for serious, in-depth thinking in the age of the TED talk. The inclusion of Ashraf Ghani, Ali Allawi and Mohamed ElBaradei—from Afghanistan, Iraq and Egypt, respectively—reflects the importance of their work on fostering democracies across the Muslim world in the wake of foreign interventions and the Arab Spring.. .

As always, the absences are as revealing as the familiar names at the top. The failure of environmental thinkers to win many votes may be a sign of the faltering energy of the green movement. Despite the presence of climate scientists lower down the list, the movement seems to lack successors to influential public intellectuals such as Rachel Carson and James Lovelock. Serious thinkers about the internet and technology are also conspicuous by their absence. The highest-placed representative of Silicon Valley is the entrepreneur Elon Musk, but beyond journalist-critics such as Evgeny Morozov and Nicholas Carr, technology still awaits its heavyweight public intellectuals (see Thomas Meaney, £).

Most striking of all is the lack of women at the top of this year’s list. The highest-placed woman in this year’s poll, at number 15, is Arundhati Roy, who has become a prominent left-wing critic of inequalities and injustice in modern India since the publication of her novel The God of Small Things over a decade ago.

The Guardian Books section has its own analysis, including speculations about the lack of women:

To qualify for this year’s world thinkers rankings, it was not enough to have written a seminal book, inspired an intellectual movement or won a Nobel prize several years ago (hence the absence from the 65-strong long list of ageing titans such as Noam Chomsky or Edward O Wilson); the selectors’ remit ruthlessly insisted on “influence over the past 12 months” and “significance to the year’s biggest questions”.

This requirement may have been a factor in the top 10 being all-male (presumably a source of frustration to the five women on the selection panel, including Prospect’s editor Bronwen Maddox), with longlistees such as Hilary Mantel, Martha Nussbaum and Sheryl Sandberg not making it through to the elite of the elite, and the likes of Germaine Greer and Naomi Klein not even making it into the 65. But it may also, of course, simply reflect the gender make-up of the monthly’s readership.

Political engagement was clearly enough for the Middle Eastern trio to meet the criterion of current influence, and others among the cerebral galacticos have been in the news too. The Higgs boson was identified at Cern in July and confirmed there last month, making him an odds-on favourite for a Nobel. Kahneman’s Thinking, Fast and Slow became a worldwide bestseller last year. Krugman, a New York Times columnist as well as a Princeton don, has been the leading critic of “the austerity delusion”. Pinker might well have made the chart anyway, but probably owes his high position to his switch from his specialist field of psycholinguistics to history in The Better Angels of Our Nature.

As for Dawkins, the continuation of wars of religion and terrorist atrocities informed by it means his atheist crusade remains relevant to the year’s biggest questions, despite the end of the Bible-bashing, war-mongering Bush era in which he first raised his banner – this week his 670,000 Twitter followers could find him (between musings about socks) rejoicing in France’s legalisation of gay marriage, ridiculing a journalist’s Muslim beliefs, and retweeting a story that the older Boston bomber “was angry that the world pictured Islam as a violent religion”. On Monday, no doubt manfully resisting efforts to deify or idolise him, the world No 1 will attend the premiere in Toronto of a documentary about his roadshow (with Lawrence Krauss) promoting science and reason.

Don’t ask me to defend the list, for I haven’t heard of half the candidates! Nor can I vouch for the sapience of Prospect readers. But I do count Richard and Steve as friends, and can testify that they clearly deserve their positions. It’s humbling and an honor to know them—and really good for my education!

Talk in North Carolina next week

April 25, 2013 • 9:27 am

A week from today, on May 2 at 7 p.m., I’ll be talking about the message of my book (and some about religion) at Appalachian State University in Boone, North Carolina (yes, it was named after Daniel Boone). You can see the announcement here for details and the venue.

I’m excited to be going for several reasons: ASU is a very good liberal arts school, which I’ve never visited; the mountains of western North Carolina are beautiful, and it will be spring; the organizers have planned an awesome series of restaurant visits for me, and I’ll get to hike up Grandfather Mountain to whet my appetite.

I doubt that there are many readers in that neck of the woods, but if you’re nearby, come on in, y’all!  They will be selling copies of WEIT, which I’ll autograph after my talk, and there will be a secret word (revealed on Tuesday or Wednesday of next week) which, if you say it to me, will get you a cat drawn in your book as well. If you want to be prepared, the ASU bookstore has been selling the book for several weeks.

Thanks to Professor Howie Neufeld for organizing my visit and the noms.

GrandfatherMountain1
The top of Grandfather Mountain. I didn’t realize there was a bridge!

 

DNA day celebration meeting – online NOW!

April 25, 2013 • 5:42 am

by Matthew Cobb

60 years ago today, Nature published three articles on the structure of DNA. The famous one by Watson and Crick (which contains no data), and two others, one by Franklin and Gosling, the other by Wilkins, Stokes and Wilson, which provide the evidence upon which Watson and Crick’s brilliant insight was based. If you’re free in the next few hours, I would recommend following this live stream of the Francis Crick Memorial Meeting being held in Cambridge to commemorate the discovery of the double helix structure of DNA.  It features some key players of the molecular genetics revolution, a Crick biographer and a leading historian of science.

Programme:

1.45–2.15 pm Matt Ridley (Crick, the early years and work at the Admiralty)
2.15–2.45 pm James Watson (Eureka moments from 28th February)
2.45–3.00 pm Jack Dunitz  (April 1953: Oxford to Cambridge with Sydney Brenner, Dorothy Hodgkin and Leslie Orgel)
3.00–3.30 pm Matthew Meselson (Semiconservative DNA replication)
3.30–4.15 pm Tea
4.15–4.45 pm Sydney Brenner (Triplet code)
4.45–5.15 pm Venki Ramakrishnan (Reading the Code: the 3D version)
5.15–5.45 pm Robert Olby (Speaking out on controversial subjects)
5.45–6.00 pm John Mollon (Crick and Caius College, and the Crick Memorial)

(N.B. All times are in British Summer Time, i.e. GMT+1)

[EDIT – the annoying buzzing that afflicted the opening 30 minutes has been fixed]