Uncommon Descent on Elizabeth Pennisi’s Science article


Two-headed quarter

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Yesterday, I ran a bit long about Elizabeth Pennisi’s new article in Science, “The momentous transition to multicellular life may not have been so hard after all.” I’m not the only one who noticed it, though; Uncommon Descent also commented (“At Science: Maybe the transition from single cells to multicellular life wasn’t that hard?“). There’s not much to it, just a longish quote from the article followed by this:

So at the basic level, there is a program that adapts single cells to multicellularity? Yes, that certainly makes multicellularity easier and even swifter but it also make traditional Darwinian explanations sound ever more stretched.

So if the evolution of multicellularity is easy, that’s evidence against “traditional Darwinian explanations.” Remember “Heads I win, tails you lose“?

…if multicellularity is really complicated, that’s evidence for intelligent design. But if multicellularity is really simple, that’s evidence for intelligent design.

The first comment is from PeterA:

Comment from PeterA

Well PeterA, I’d love to tell you, but I was banned from Uncommon Descent for reminding Barry Arrington of something he didn’t want reminded of. So I guess I’ll have to answer here.

Cornelius Hunter said it was hard:

[The evolution of multicellularity] is yet another challenging topic because it contradicts the evolutionary model. The most obvious contradiction is that it requires a series profoundly sophisticated enhancements and changes to occur in a population of unicellular organisms.

Anne Gauger said it was hard (I addressed her assertions here and here):

Missing from this story [multicellularity in Volvox], though, are the details necessary for this 12-step progression to occur. There’s the matter of incomplete cell division, cell separation later, and matrix formation. Then there’s the matter of specialization. To get the specialization of somatic from germ cells requires the development of at least three proteins. Also, the embryos produced by those reproductive cells are inside out — the flagella are on the inside, which makes them useless for swimming, and the gonidia are on the outside. As a result, the embryo must turn itself inside out when it reaches the right size. This requires that the somatic cells change shape to bottle- or spindle-shaped cells, depending on their position in the embryo. This shape change requires both microtubules and a little motor protein called kinesin. Neither microtubules or kinesin are present in bacteria so their origin must be accounted for. The selective advantage of each step is not clear.

Paul Nelson said it was hard:

…the challenge [of explaining the evolution of multicellularity] is just getting to the point functionally where natural selection actually operates. That’s an engineering problem, and selection will not help.

In fact,

Pretty much any time real scientists learn something new about the origins of multicellularity, writers on intelligent design blogs Evolution News & Views and Uncommon Descent feel compelled to tell us why it’s wrong (for example, herehereherehereherehereherehereherehereherehere, and here).

Does that help? If you want to pretend that intelligent design advocates haven’t been arguing for years that the evolution of multicellularity was hard–and that this difficulty supported intelligent design–I can’t stop you. If, on the other hand, you really didn’t know, now you do.

 

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