The Great Wall of China: a physical barrier to gene flow?

Abstract

One population from each of six plant species along both sides of the Juyong-guan Great Wall, together with one population from each of five species along both sides of a path on a mountain top near Juyong-guan, were selected to study the effect of the Great Wall as a barrier on genetic differentiation between two subpopulations using RAPD markers. Significant genetic differentiation was found between the subpopulations on both sides of the Great Wall. A wind-pollinated woody species, Ulmus pumila, showed less genetic differentiation than four insect-pollinated species: Prunus armeniaca, Ziziphus jujuba, Vitex negundo, and Heteropappus hispidus. Cleistogenes caespitosa, a windpollinated perennial herb, displayed more genetic differentiation between subpopulations than the insect-pollinated species because of its propagation strategy. Although AMOVA analysis showed that subpopulations divided by a mountain path had diverged genetically, the variance component between the subpopulations on both sides of the Great Wall was significantly larger than that between the subpopulations at the control site. Therefore, it is reasonable to deduce that the Juyong-guan Great Wall has served as a physical barrier to gene flow between subpopulations separated for more than 600 years.

Trees in the desert: Reproduction and genetic structure of fragmented Ulmus pumila forests in Mongolian drylands

“…Schiebold et al, 2009;Steinger et al, 1996;Wesche et al, 2005b). RAPDs have also been used to describe genetic structure in U. pumila (Su et al, 2003).…”

Fine- and landscape-scale spatial genetic structure of cushion rockjasmine, Androsace tapete (Primulaceae), across southern Qinghai-Tibetan Plateau

“…However, some landscape features (e.g. rivers or mountains) may serve as important barriers for gene flow (Manel et al 2003;Su et al 2003;Coulon et al 2006;Cushman et al 2006), thus result in landscape-level spatial genetic patterns that fulfill the expectations of isolation by 'biological distance' rather than of isolation by 'Euclidean distance' model (Hirao and Kudo 2004;McRae 2006).…”

Testing the effect of the Himalayan mountains as a physical barrier to gene flow in Hippophae tibetana Schlect. (Elaeagnaceae)

“…Geographic isolation is considered to play a critical role in the genetic differentiation of plant populations [1], [2]. Physical barriers, such as mountain ranges, rivers, and glaciers may prevent gene flow and cause genetic differentiation of isolated natural populations [1], [2], [3], [4], [5].…”