Those differences may involve divergence in traits (e.g., body size), the habitats used by the competing species, or the times of year that the species use a particular habitat, and they may also involve multiple forms of selection other than competition (Pfennig and Pfennig 2009).
Clear examples of ecological speciation exist, often involving divergence in trophic morphology.
However, the best-known example of disruptive selection is inconclusive and might have involved divergence in allopatry preceding secondary contact [ 6, 65, 66].
These data, together with the results of our phylogenetic analysis, strongly suggest that the evolution of the two invertase outparalogs in Ceratocystis involved divergence from a common ancestor by the loss and gain of motifs at their N-terminals to ultimately yield a cell wall and a vacuolar invertase.
Although variation at S-loci is often found to predate speciation [ 83, 84], the role of these loci in mating compatibility and reproduction gives them potential to be involved in divergence in some contexts.
We would like to know whether the adaptation involved expression divergence in all chemosensory gene families, including recently identified Ir, Csp, and Che genes.
One of the hypotheses we wanted to test was whether functional divergence between the different GroEL copies also involved a divergence in their coevolutionary patterns with known GroEL protein clients.
These negative effects of pollinator sharing can be reduced if plants involved show divergences in floral structures that allow mechanical isolation (Grant 1992; Fulton and Hodges 1999) and place their pollen on different body parts of the pollinator (Kay 2006; Muchhala and Potts 2007; Muchhala 2008).
Rather than imagining that speciation means turning lions into tigers, or bears into cows, or fish into humans, they will see that speciation involves a subtle divergence in the evolutionary trajectories taken by populations.
The low diversity in the sequences recovered for both taxa however indicates that incomplete lineage sorting is a likely cause for this pattern, in particular the processes involved in divergence of peripheral isolates as a result of founder effects [17], [18].
