From David Reznick and Joseph Travis at Science:
Questionable predictability is not specific to stick insects. Nosil et al. analyzed data sets for other long-term studies of evolution in various species, including Galapagos finches and the peppered moth, and show that they also offer low temporal predictability. In these cases, the likely cause is also multiple forms of selection the strength of which varies over time.
These results show that an iconic example of a simple trait subjected to a single agent of strong selection is actually much more complicated. Similar lessons have been taught by other seemingly simple phenomena. For example, the complex ways in which known agents of selection on the color polymorphism of Cepaea snails meant that “each population is subject to a unique explanation” (10). This is in stark contrast to studies of microbial, viral, and immune system selection, for which evolution seems to be highly predictable (13). Why this is the case, when it is not so in organisms such as stick insects and others, is a new challenge for evolutionary biologists. More. (paywall)
Hmmm. How sure are we in the other cases (“microbial, viral, and immune system selection”), that the authors have not examined in detail, that evolution is “highly predictable”? Listening to some Darwinians hold forth I’d want independent corroboration for anything they say, when warming to their favorite themes.
See also: Evolution predictable or haphazard? Or is the discussion a waste of time?
Convergent evolution: “Emerging view” that evolution is predictable?
If evolution is unpredictable and irreversible, … was Stephen Jay Gould wrong?