One thing that threw up a warning flag in the article was this sentence:
I suggest that the true source of macroevolutionary change lies in the non-linear, or chaotic, dynamics of the relationship between genotype and phenotype - the actual organism and all its traits.
My understanding is that chaotic dynamical systems are just a subset of nonlinear dynamical systems, so the whole title seems sensational and as if the author just used "chaos" not because he has reason to believe that evolution is actually chaotic, but instead because chaos sounds really cool.
If we simply restrict the theory to evolution being nonlinear, that's almost certainly true. Why would evolution be linear? To paraphrase Stanislaw Ulam, talking about "non-linear dynamics" is like talking about "non-elephant zoology."
The author does support the chaos hypothesis later on in the article by talking about the tree of life being fractal, but I'm definitely going to need more evidence than a single paragraph without references.
Yes; as far as I can tell, the only thing the author says that is remotely related to chaos is that arbitrary choices get frozen in place. This is the lack of ergodicity, and thus the lack of chaos.
The author makes a claim: "it is impossible to predict how a given species will respond to environmental change."
This claim has been shown false. The first thing that comes to mind is the bajillion fruit fly studies.
It's basically equivalent to the claim that experiments in evolution are not repeatable. Partly true, but mostly false. The E. Coli in http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment evolved the ability to live on citrate, after all. They didn't grow wings and fly. In fact, I think one of the papers that's come out of that experiment was an analysis showing that the rate of beneficial mutations was roughly constant.
He also displays a number of bad traits, such as appeal to authority rather than giving evidence, that sort of thing.
:
Research on animals has come to similarly unexpected conclusions, albeit based on sparser fossil records. For example, palaeontologist Russell Graham at Illinois State Museum has looked at North American mammals and palaeontologist Russell Coope at the University of Birmingham in the UK has examined insects (Annual Review of Ecology and Systematics, vol 10, p 247). Both studies show that most species remain unchanged for hundreds of thousands of years, perhaps longer, and across several ice ages. Species undergo major changes in distribution and abundance, but show no evolution of morphological characteristics despite major environmental changes. That is not to say that major evolutionary change such as speciation doesn't happen. But recent "molecular clock" research suggests the link between speciation and environmental change is weak at best. Molecular clock approaches allow us to estimate when two closely related modern species split from a common ancestor by comparing their DNA. Most of this work has been carried out in birds, and shows that new species appear more or less continuously, regardless of the dramatic climatic oscillations of the Quaternary or the longer term cooling that preceded it
The hypothesis is that there's very little possibility of finding patterns in evolution. What do you think?
One thing that threw up a warning flag in the article was this sentence:
I suggest that the true source of macroevolutionary change lies in the non-linear, or chaotic, dynamics of the relationship between genotype and phenotype - the actual organism and all its traits.
My understanding is that chaotic dynamical systems are just a subset of nonlinear dynamical systems, so the whole title seems sensational and as if the author just used "chaos" not because he has reason to believe that evolution is actually chaotic, but instead because chaos sounds really cool.
If we simply restrict the theory to evolution being nonlinear, that's almost certainly true. Why would evolution be linear? To paraphrase Stanislaw Ulam, talking about "non-linear dynamics" is like talking about "non-elephant zoology."
The author does support the chaos hypothesis later on in the article by talking about the tree of life being fractal, but I'm definitely going to need more evidence than a single paragraph without references.
Yes; as far as I can tell, the only thing the author says that is remotely related to chaos is that arbitrary choices get frozen in place. This is the lack of ergodicity, and thus the lack of chaos.