Populationsgenetik konsekvenser av skogsträd biologi på artbildning och anpassning

Tidsperiod:

1 oktober – 31 december 2009

Projektledare:

Martin Lascoux

Finansiär:

Formas

Bidragstyp:

Oklassificerat

Budget:

27 000 SEK

Forest tree species often combine long generation times, large effective population sizes and a high degree of hybridization with related species. These characteristics have important consequences on the distribution of nucleotide variation within and between species and thereby on the studies of speciation and adaptation. For example, even in species that separated a long time ago, the number of generations is limited and genetic drift is weak so that fixed sites tend to be rare and shared polymorphisms common. The consequences for speciation will be illustrated by two recent analyses in the Picea genus, one focusing on the divergence of three major boreal species with large ranges and a Tertiary relict with a very limited distribution, the other on the complex speciation process in a group of four species from the Tibetan Plateau and adjacent areas. The general emerging pattern is one of recent divergence, often accompanied by subsequent gene flow and a strong impact of demographic history on the pattern of nucleotide variation. The implication of these results and, more generally, of the use of comparative population genetic studies to understand evolutionary processes and identify adaptive genes will be discussed.