Harnessing paleo‐environmental modeling and genetic data to predict intraspecific genetic structure

Abstract

Spatially explicit simulations of gene flow within complex landscapes could help forecast the responses of populations to global and anthropological changes. Simulating how past climate change shaped intraspecific genetic variation can provide a validation of models in anticipation of their use to predict future changes. We review simulation models that provide inferences on population genetic structure. Existing simulation models generally integrate complex demographic and genetic processes but are less focused on the landscape dynamics. In contrast to previous approaches integrating detailed demographic and genetic processes and only secondarily landscape dynamics, we present a model based on parsimonious biological mechanisms combining habitat suitability and cellular processes, applicable to complex landscapes. The simulation model takes as input (a) the species dispersal capacities as the main biological parameter, (b) the species habitat suitability, and (c) the landscape structure, modulating dispersal. Our model emphasizes the role of landscape features and their temporal dynamics in generating genetic differentiation among populations within species. We illustrate our model on caribou/reindeer populations sampled across the entire species distribution range in the Northern Hemisphere. We show that simulations over the past 21 kyr predict a population genetic structure that matches empirical data. This approach looking at the impact of historical landscape dynamics on intraspecific structure can be used to forecast population structure under climate change scenarios and evaluate how species range shifts might induce erosion of genetic variation within species.

gen3sis: A general engine for eco-evolutionary simulations of the processes that shape Earth’s biodiversity

“…Using gen3sis, it is possible to explore the multiple causal pathways between temperature and biodiversity, with the study of the past providing insight into species responses to ongoing climate change [ 174 ]. Finally, gen3sis can be used to explore not only species diversity, but also intraspecific genetic structure and thus the correspondence between these diversity levels [ 175 ].…”

Broadening Predictive Understanding of Species’ Range Responses to Climate Change: The Case of Aloidendron dichotomum

“…Huntley et al (2016) invoked a similar explanation for current geographic patterns of bird species richness in this region, and more broadly in southern Africa. Certainly, the impact of changing climate patterns through the LGM and mid-Holocene until the present day has been important for current geographic distributions and spatial patterns of genetic diversity for multiple long-lived tree species globally (Hao et al, 2018;Lyam et al, 2020;Yannic et al, 2020;Łabiszak et al, 2021).…”

CHELSA-TraCE21k v1.0. Downscaled transient temperature and precipitation data since the last glacial maximum

“…The strong coupling between temperature and glacial extent in CHELSA-TraCE21k generates an increase in glacial extent more than a sudden collapse during this time period, which seems to override the signal from the ICE6G forcing data in CHELSA-TraCE21k. cycle since the LGM, have had a significant influence on the distribution of ecosystems (Williams and Jackson, 2007), species (Hampe and Jump, 2011;Hewitt, 1999), and as a result on intraspecific genetic structures and speciation (Alsos et al, 2012;Pellissier et al, 2015;Yannic et al, 2014Yannic et al, , 2020.…”