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Convergence or parallelism?: Kevin Padian at Nature on Jonathan Losos’ Improbable Destinies

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Integrative biologist Kevin Padian reviews Improbable Destinies: Fate, Chance, and the Future of Evolution by Jonathan B. Losos at Nature. He likes it but with quite a few qualifications:

Early in Jonathan Losos’s Improbable Destinies, the narrative goes off the rails. Losos sets up the problem of historical contingency in evolution by repeating the story that 66 million years ago, at the end of the Cretaceous period, an asteroid smacked into Earth, killing off the dinosaurs and paving the way for mammalian success. Had the asteroid missed, he writes, dinosaurs would have continued their domination and we humans might never have evolved.

The problem is much evidence has come to light in recent years that he dinosaurs were declining anyway and the mammals were doing reasonably well.
Note: There is an excerpt from the book at ScienceFriday.

Nevertheless, Improbable Destinies is deep, broad, brilliant and thought-provoking. Losos explores the meaning of terms such as fate, chance, convergence and contingency in evolution. Why do similar solutions — morphological, genetic and molecular — crop up again and again? He became intrigued by these questions when, as a student, he began to study the Caribbean Anolis lizards, following groundbreaking work by ecologist Thomas Schoener. These lizards inhabit a great range of island sizes and habitats, and tend to evolve similar adaptations and roles in similar circumstances. However, species on different islands that resemble each other aren’t each other’s closest relatives. Why not?

Why not indeed? Padian has some thoughts on this type of convergence:

Many call this convergence; I prefer the term parallelism for closely related lineages. ‘Convergence’ is appropriate for reinvention in very different groups — the superficially similar wings of birds and pterosaurs, or the elongated grub-seeking fingers of the aye-aye (Daubentonia madagascariensis) and striped possum (Dactylopsila trivirgata). We can catalogue examples all day, but is there any real theory of convergence? We cannot assert that some lineages are ‘fated’ to converge on these features. More.

Actually, hardly anyone asserts that convergence is “fated”; the problem is that it isn’t very Darwinian. Padian is president of the National Center for Science Education, which possibly accounts for the slam at Lamarck that immediately follows: “Biological ideas of determinism went out with Jean-Baptiste Lamarck in the late eighteenth century.”

As to a theory of convergence, it would be nice to study convergence much more before attempting one: How do large amounts of complex, specified information that cannot have evolved randomly within the life of this universe (Darwinism = natural selection acting on random mutations) duplicate themselves in widely different life forms? If we knew how, it might be easier to predict whether and when.

See also: New book: Evolution happens more quickly than we think If all “evolution” meant was variations in finch beaks and lizards, this book might be the answer. But let’s not kid ourselves.

and

Evolution appears to converge on goals—but in Darwinian terms, is that possible?

Comments
J-Mac @3 Lotos?Dionisio
August 23, 2017
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I see much digression in this discussion. Let's pay attention to the bottom line, which is briefly explained @2. Anything outside that is off topic gossiping at best. Ok? :)Dionisio
August 23, 2017
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Actually, hardly anyone asserts that convergence is “fated”; the problem is that it isn’t very Darwinian.
Why not? Why can't different organisms evolve similar solutions to the same problem?Bob O'H
August 23, 2017
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Dawkins says the opposite... Evolution is too slow to be observed... http://www.inquisitr.com/1917988/evolution-observable-in-action-today-richard-dawkins-explains/ I guess Lotos is talking about the 4th or the 5th way of evolution and Dawkins...who hell knows.. Joseph Felsenstein says there is 10 billion species on the earth right now all of them evolving but the transitions into new species are not observable now in any of them...But if we wait long enough we will see new species... Are there more than 67 ways of evolution? If there are, I'd like to know... I'm getting tired of this evolutionary bs...J-Mac
August 22, 2017
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Ok, let's repeat this here too: This was posted in another thread, but maybe it fits in this one too. Are they referring to the embedded variability framework (EVF) that operates within the biological systems? Don’t birds remain birds? Bacteria remain bacteria? Plants remain plants? Amphibians remain amphibians? Apes remain apes? Humans remain humans? Many ethnic groups but all equally humans. The evo-devo fundamental conundrum remains unresolved: Dev(d) = Dev(a) + Delta(a,d) That’s the bottom line. The rest is speculation. Without Delta(a,d) there’s no way to get Dev(d) from Dev(a). That’s daydreaming illusion. Figment in their imagination. Pie pie in the sky. It’s time to get serious. A couple of years ago a science professor claimed to know exactly how morphogen gradients form, but even today the research papers point to the complexity of such an important process that still is poorly understood. As outstanding questions get answered new ones are raised. However, as every new discovery sheds more light on the elaborate cellular and molecular choreographies orchestrated within the biological systems, the emerging big picture points more and more to marvelously designed systems. BTW, ‘a’ stands for ‘ancestor’ and ‘d’ for ‘descendant’. Dev(x) is the entire developmental process of a given biological system ‘x’. Delta(x,y) is the entire set of spatiotemporal changes required in Dev(x) in order to get Dev(y). All the bells and whistles have to be included. The whole enchilada. The point is to show how to get Delta(x,y) assuming that we know Dev(x) and Dev(y). I challenge that professor and his cousins to show me one example that satisfies the above formulation. We can sweep and mop the floor with all their baseless ideas. With every new discovery their situation will get even worse.Dionisio
August 22, 2017
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Two words come to mind: "bzdura" (Polish language) and "yerunda" (Russian language). Actually, a third word comes to mind too: "tonterias" (Spanish language). :)Dionisio
August 22, 2017
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