Quantifying the potential for future introgressive hybridization at continental and community scales among suites of interfertile species
by Charles Cannon | The Morton Arboretum
Abstract ID: 60
Event: The 3rd AsiaEvo Conference
Topic: Impact of introgessive hybridization on tropical diversification
Presenter Name: Charles Cannon

Introgressive hybridization (IH), where small fractions of the entire genome are shared among interfertile species through initial F1 hybridization and subsequent integration through backcrosses, is increasingly being detected in many different organisms.  This natural process has played a significant role in the diversification of many major tropical lineages.  Given the ecological and environmental settings of tropical forests, particularly for trees, the potential for IH is quite large.  In species rich forests, where numerous interfertile species are sympatric in any one location, IH also creates a complex network of potential pathways for adaptive genes to be shared.  One of the most likely ways isolated species become maladaptive is through the loss of critical function, through genetic drift, particularly if that function is only required sporadically over very long periods of time.  Here, I discuss how existing geospatial data about species distributions can be used to explore and quantify the potential for IH among suites of interfertile species.  These estimates and descriptors can be applied at various spatial scales using different approaches to characterize species distribution.  Additionally, I discuss how the network properties of the syngameon (the suite of interfertile species) facilitates sharing of adaptive alleles and has synergistic effects of diversification capacity of a group.

Given the rapid change in environmental conditions and the emergence of novel ecosystems, species will need to greatly accelerate their adaptive processes, precisely at a moment when most of these processes are being disrupted by human activity.  The likelihood of IH will probably substantially increase during the Anthropocene, due to declining population sizes in each species, increased mobility among sites, and the increasing adaptiveness of transgressive or novel phenotypes in novel environments.   Understanding the potential future dynamics of IH and the probably outcomes from the process given different assumptions are important questions for biodiversity conservation.  Enabling the natural potential in IH may be one of the most effective means to sustain their adaptive capacity of threatened species.