Figure 1.
Haplotype maps of 14 Afrotropical tree taxa (dataset 1).
Sizes of circles are proportional to the sample sizes of each population, haplotypes are colour-coded. Statistical parsimony networks of haplotypes are included for each taxon: each link represents a single mutation, white circles indicate unobserved putative haplotypes and the black box on the Strombosiopsis tetrandra network represents 26 mutations. The scale bar on the maps corresponds to 200 km.
Figure 2.
Two physioclimatic features of the Lower Guinea region that led to the formulation of alternative evolutionary scenarios for Afrotropical tree taxa.
A) The W-E environmental gradient, B) the N-S seasonal inversion, illustrated by the difference of January and July precipitation (mm).
Table 1.
Diversity patterns at the trnC-ycf6 region in 14 Afrotropical tree taxa.
Figure 3.
Haplotype maps of four Afrotropical tree species (dataset 2).
Sizes of circles are proportional to the sample sizes of each population, haplotypes are colour-coded. Statistical parsimony networks of haplotypes are included for each species: each link represents a single mutation; white circles indicate unobserved putative haplotypes. Red lines correspond to the three strongest genetic barriers (BARRIER program) identified in each species.
Figure 4.
Graphical representation of two evolutionary scenarios tested using coalescent simulations.
A) population divergence scenario, B) constant population size scenario.
Table 2.
Tests of population expansion and patterns of isolation by distance in 14 Afrotropical tree taxa.
Table 3.
Analysis of variance in 14 Afrotropical tree taxa under two evolutionary scenarios.
Table 4.
Diversity estimates across 14 Afrotropical tree taxa under two evolutionary scenarios (dataset 1).
Table 5.
Diversity estimates in 14 Afrotropical tree taxa under two evolutionary scenarios.
Table 6.
Differentiation patterns in 14 Afrotropical tree taxa under two evolutionary scenarios.
Table 7.
Simulation results showing summary statistics and the expected proportion of significant differentiation tests under divergence or constant population size scenarios for simulated deme sizes, N, and mutation rates, µ, and their comparison to observed data from dataset 1.
Figure 5.
Graphical representation of co-location of the three strongest genetic barriers (barrier density) observed across four Afrotropical tree species (dataset 2).
Barriers (in blue) are based on the pair-wise differentiation (GST) among sampling locations. More intense coloration indicates higher barrier density.