Ecosystem size matters: The dimensionality of intralacustrine diversification in Icelandic stickleback is predicted by lake size ...

• Main Authors: Kristjánsson, B. K., Lucek, Kay Jurka Olaf, Skúlason, S., Seehausen, Ole
• Format: Text
• Language: English
• Published: John Wiley & Sons, Inc. 2016
• Subjects: 570 Life sciences; biology; Iceland
• Online Access: https://dx.doi.org/10.7892/boris.82585; http://boris.unibe.ch/82585/

Cases of evolutionary diversification can be characterized along a continuum from weak to strong genetic and phenotypic differentiation. Several factors may facilitate or constrain the differentiation process. Comparative analyses of replicates of the same taxon at different stages of differentiation can be useful to identify these factors. We estimated the number of distinct phenotypic groups in threespine stickleback populations from nine lakes in Iceland and in one marine population. Using the inferred number of phenotypic groups in each lake, genetic divergence from the marine population, and physical lake and landscape variables, we tested if ecosystem size, approximated by lake size and depth, or isolation from the ancestral marine gene pool predict the occurrence and the extent of phenotypic and genetic diversification within lakes. We find intralacustrine phenotypic diversification to be the rule rather than the exception, occurring in all but the youngest lake population and being manifest in ...