Speciation and historical migration pattern interaction: examples from P. nigra and P. sylvestris phylogeography

Abstract

Here, from macrophylogeographic mtDNA empirical data, we propose a scenario for the evolution and speciation of two important forest trees, European black pine and Scotch pine, and their multiple subspecies and varieties. Molecular clock simulations revealed that INDEL variability in the Pinus mitochondrial genome is relatively old, i.e., from the Pliocene-Miocene epoch, and related to historical tectonic continental fluctuations rather than to climate change at a large geographic scale. For conservation and management biodiversity program recommendations, special attention is given to the relationships between different speciation models, historical migration patterns, and differences between peripheral and central populations. Species evolution involves the mixing of different speciation modes, and every speciation mode has different effects on different DNA types (e.g., mitochondrial vs. chloroplast vs. nuclear DNA). The misbalance between the contributions of different meta-population census sizes vs. effective population sizes to asymmetric migration patterns is the result of different genotypes (and subphylogenetic lines) responding to selection pressure and adaptive evolution. We propose initial minimal size of conservation unit (between 3 and 5 ha) from central and marginal natural area of distribution for both species in the dynamic management system for practical forest genetic diversity management. The proposed physical sizes were determined by the effective population size, effective radius of seed distribution data, forest density age dynamics, succession pattern, natural selection pressing and species biology [R-17].