Life cycles in major transitions, and some clueless critique

Jordi van Gestel and Corina Tarnita have published a ‘Perspective’ in PNAS, “On the origin of biological construction, with a focus on multicellularity“:

…we propose an integrative bottom-up approach for studying the dynamics underlying hierarchical evolutionary transitions, which builds on and synthesizes existing knowledge. This approach highlights the crucial role of the ecology and development of the solitary ancestor in the emergence and subsequent evolution of groups, and it stresses the paramount importance of the life cycle: only by evaluating groups in the context of their life cycle can we unravel the evolutionary trajectory of hierarchical transitions.

van Gestel 2017 Fig. 2

Figure 2 from van Gestel and Tarnita, 2017. Relationship between life stages in hypothesized life cycles of solitary ancestors and group formation in derived group life cycles. (Upper) Simplified depiction of hypothesized ancestral solitary life cycles of the green alga Volvox carteri, the cellular slime mold Dictyostelium discoideum, and the wasp Polistes metricus. Life cycles here consist of a life stage expressed under good conditions (black) and a life stage expressed under adverse conditions (green). For the latter life stage, we show an environmental signal that might trigger it and some phenotypic consequences. (Lower) Simplified depiction of group life cycles of: V. carteri, D. discoideum, and P. metricus. Developmental program underlying life stages in solitary ancestor is co-opted for group formation (shown in green): differentiation of somatic cells (V. carteri), fruiting body formation (D. discoideum), and appearance of foundress phenotype (P. metricus).

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A confused mess, part 2

xkcd Wrong on the Internet

Comic by Randall Munroe, xkcd (of course).

Maybe by the time I have part 2 written up, someone will tell me in the comments why we evolutionary biologists shouldn’t just hang up our hats in light of pre-antibiotic antibiotic resistance.

I really didn’t mean to leave that hanging for three weeks. That was the end of part 1 of my look at Phillip Cunningham’s video, “Darwin vs. Microbes,” in which Cunningham argues that antibiotic resistance is not an example of evolution because (among other reasons),

…contrary to Darwinian thought, it is now found that antibiotic resistance, instead of being an ability that is new for bacteria, is an ability that is ancient.

Boom, game over, creationists win, right? I mean, how can antibiotic resistance have evolved millions of years ago if Alexander Fleming didn’t invent penicillin until 1928? [Read more…]

In which I agree with Michael Egnor

Can you be good without God? Of the various questions raised in the theist/atheist debate, this question has, I believe, occasioned more witless commentary than any other.

–Michael Egnor, Evolution News & Views 2017-09-05

I couldn’t agree more. And you’ll find no better example of that witless commentary than Egnor’s article itself.

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In their own words, part 2

Evolution News & Views

I previously pointed out that Casey Luskin’s “false, straw-man [version] of ID” bears a striking resemblance to intelligent design advocate Michael Behe’s actual definition:

Let me get this straight:

life is so complex, it could not have evolved” is a “false, straw-man version” of

Cells are simply too complex to have evolved.

I promised that I would get to the second part of Luskin’s “straw-man version,”

…therefore it was designed by a supernatural intelligence,

and that’s what I mean to address in this post. Maybe Luskin wasn’t claiming that ID critics mischaracterize the logic that leads ID advocates to reject evolution, but rather that they mistakenly (or deceitfully) portray ID advocates as inferring supernatural causation. If so, he’s not alone. Advocates of intelligent design frequently deny that their theory has anything to do with the supernatural, and they imply that efforts to portray it as such are deceitful or, at best, misinformed.

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In their own words, part 1

Evolution News & Views

Cdesign proponentsists often complain that critics attack straw man versions rather than their actual arguments. That must be really frustrating; as I’ve said before, if you have good arguments, you don’t need to misrepresent your opponents’. Here, for example is Casey Luskin on Evolution News & Views:

Many critics of intelligent design have promoted false, straw-man versions of ID, typically going something like this:

“Intelligent design claims that life is so complex, it could not have evolved, therefore it was designed by a supernatural intelligence.”

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Get your story straight, will you?

Here are a few of the things that would or do support intelligent design, according to various authors on Evolution News & Views:

If evolving multicellularity is complicated. — Cornelius Hunter, Anne Gauger

If evolving multicellularity is simple. — Unsigned Evolution News & Views article

If the human and chimpanzee genomes are very different. — Denyse O’Leary, Casey Luskin, David Klinghoffer, Anne Gauger

If the human and chimpanzee genomes are very similar. — Cornelius Hunter

If life is uncommon in the universe. — David Klinghoffer

If life is common in the universe. — David Klinghoffer

So intelligent design is in the enviable position of being supported equally well by mutually exclusive predictions. Heads I win, tails you lose! Now we can add Kirk Dunston to that last entry (“Could Atheism Survive the Discovery of Extraterrestrial Life?“):

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Convergence falsifies evolution, according to Cornelius Hunter

Xerus princeps

Xerus princeps, the mountain ground squirrel.

Before I saw the light and switched to studying Volvox, I studied squirrels. With apologies to Iris Vander Pluym, squirrels are cool. If you grew up in the squirrel-deprived eastern U.S., you might not realize that there are over a hundred species. Chipmunks are squirrels. Marmots are fat squirrels. Prairie dogs are adorable squirrels.

Most of my squirrel work, and some of my Volvox work, has focused on understanding the evolutionary relationships among species. This fits in the subfield of evolutionary biology known as phylogenetics. Phylogenetics results are often visualized as trees and published in journals like CladisticsMolecular Phylogenetics and Evolution, and Systematic Biology. Phylogenetics is a vast subfield, with a huge number of papers devoted to developing methods that are theoretically and empirically sound.

Cornelius Hunter understands none of this. In a recent post over at Evolution News and Science Today (which used to be Evolution News and Views…when did that change?), he argues against the whole idea of common descent, the very foundation of phylogenetics. Dr. Hunter argues that convergence, similarities among distantly related species, falsifies evolution. The nature of his arguments shows pretty conclusively that he doesn’t understand the basic logic of what he’s criticizing.

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Devolution isn’t a thing

Devo

Yesterday I volunteered as a Meeting Mentor at the AbSciCon meeting. It’s not a big commitment; essentially all you have to do is hang out with a high school student for half a day, going to talks and enjoying the meeting as you normally would.

During a break, I was chatting with my mentee about Betül Kaçar’s research, and he surprised me by pointing out that (as he put it), “Devolution isn’t a thing.” The student I was paired with is interested in physics and space exploration, but his comment showed an insight that not even all professional biologists really own. From what I’ve seen, it’s an insight that very few creationists own.

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New fossil proves plants are younger than previously thought

That’s not a headline you’re likely to see again. Hopefully it made you think something along the lines of “how does that work, exactly?” Because it doesn’t. If your estimate of the age of a taxon is based on its oldest known fossil, finding a newer fossil isn’t likely to change that estimate. If it’s an extinct group, a newer fossil might show that it stuck around later than you thought, but not that it originated later. Paleontologists recognize that fossil-based estimates of ages are almost always underestimates, since the fossil record is spotty (and generally spottier the further back you go).

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Responses from both Davids (I’m Goliath)

David Klinghoffer and David Coppedge have both responded to my post “Lies of omission and straight-up lies.” Klinghoffer did so in a post on Evolution News and Views, “You Already Support Goliath with Your Tax Dollars; Won’t You Consider Balancing the Scales?“. In it, he calls me a bully for pointing out inconsistencies and omissions in his and Coppedge’s accounts. What he doesn’t do is refute anything I said.

Instead, he reveals how deeply the persecution narrative is embedded in his worldview. So deeply, in fact, that mere criticism is perceived as persecution and bullying. I’ve mentioned the persecution complex before (“The Discovery Institute still doesn’t understand free speech“), and I’m sure others have as well. Here’s how Klinghoffer responds to having inconsistencies in his narrative pointed out:

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