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?