Time for a revision? Maureen O’Malley and Russell Powell on Major Transitions, part 1

The so-called ‘Major Transitions’ framework is an attempt to explain the hierarchical structure of life on Earth: genes within chromosomes, chromosomes within cells, cells within cells (eukaryotic cells), individuals within sexual partnerships, cells within multicellular organisms, and organisms within societies. The best-known attempt to unify the origins of these relationships is a book by John Maynard Smith* and Eörs Szathmáry, The Major Transitions in Evolution.

MajorTransitionsCover

First published in 1995, the book focused on the origins of these hierarchical levels, connecting them with the unifying theme that

…entities that were capable of independent replication before the transition can replicate only as part of a larger whole after it.

For example, after a transition from unicellular to multicellular organisms (there were several), cellular reproduction either contributes to the growth of the organism or to production of new multicellular organisms.

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So much wrong

Say what you want about the Discovery Institute; they are prolific! Evolution News & Views alone publishes several articles a day. I’m lucky if I can crank out three a week, and I try to limit the proportion that are about cdesign proponentsists being wrong. It’s a continual temptation, because those posts are easier to write than, say, digging into a peer-reviewed article. PZ promises me that blogging on FtB will eventually earn me enough to buy a cup of coffee, but I have a job. All of this means that I have to let a lot of big, juicy targets sail by. So, quickly:

DentonLeaves

Thank you, Michael Denton; no evolutionary biologist ever considered the possibility that not everything is adaptive. To answer your question, some aspects of leaf shape are adaptive, some are not. Next.

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Dual first authors

Thunderdome

A forthcoming paper in Philosophy of Science has dual first authors, Kate E. Lynch and Pierrick Bourrat (I’ve written about Dr. Bourrat’s work previously, which is part of the reason this is on my radar):

Author order has been decided randomly, therefore both authors are first authors. KEL and PB contributed equally to the manuscript. KEL’s distinct contribution was the ideas developed in Section 3. PB’s distinct contribution was the ideas developed in sections 4 and 5 and the equations in Section 3. Other sections received equal contributions from both authors.

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Intelligent design’s double standard

Double Tourbillon 30° mechanism by Greubel Forsey. Creative Commons image from Wikimedia.

Double Tourbillon 30° mechanism by Greubel Forsey. Creative Commons image from Wikimedia.

Despite protests to the contrary, intelligent design is a god of the gaps argument. Take a look at Discovery Institute blogs, and a large portion of the posts are essentially arguing that some aspect of biology or biochemistry is really, really complicated (for example, Howard Glicksman’s posts at Evolution News & Views). As if there are bunches of evolutionary biologists running around saying life is simple. So most intelligent design arguments boil down to “there’s no plausible evolutionary explanation for this aspect of biology, therefore it must have been designed.” And cdesign proponentsists insist on a high standard of evidence to consider an evolutionary explanation plausible. For example, here’s Michael Behe’s standard for believing that “…complex biochemical systems could arise by a random mutation and natural selection…”:

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F paywalls

CritRevPaywall

Sure, I have $2000 a year to spend on this one journal.

I’ve written twice before about paywalls and how to get around them (On paywalls, Paywalls revisited). Paywalls pop up when you try to read a peer-reviewed article that you don’t have access to. If you work at a university, museum, or other research institution, you probably see these only every once in a while, because most such institutions have subscriptions to most of the big journals. Otherwise, you’re pretty much out of luck. [Warning: PG-13 below the fold]

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David Queller on individuality

Dictyostelium discoideum. Photographed by Usman Bashir (Queller/Strassmann Lab, Washington University in St. Louis). Licensed under the Creative Commons Attribution-Share Alike 4.0 International license.

Dictyostelium discoideum. Photographed by Usman Bashir (Queller/Strassmann Lab, Washington University in St. Louis). CC-BY-SA-4.0 License. Image obtained from Wikimedia Commons.

In the Major Transitions class, the students keep pointing out that the transitions on Maynard Smith and Szathmáry’s list come in two flavors with very different properties. Sure, there are some important similarities between multicellular organisms and social insects, but they are quite different from cellular slime molds and the conspiracy of prokaryotes that make up eukaryotes.
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Following Fierce Roller

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There doesn’t seem to be an RSS button here at Freethought Blogs, but if you use Feedly or some other feed reader (Jema), you can subscribe to fierce roller at https://freethoughtblogs.com/fierceroller/?feed=rss2. I haven’t yet figured out how to subscribe by email, but if that’s your preference there is a slightly kludgy solution: you could convert the rss feed into emails using a service like feedmyinbox or rssfwd.