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?
Evolution just might be chaotic
The Chaos Theory of Evolution
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The hypothesis is that there’s very little possibility of finding patterns in evolution. What do you think?