Ryan Hernandez, PhD

Background:  Modern sequencing technologies have revolutionized genetic research.  The entire genomes of 1000s of individuals across the world are currently being sequenced.  The Hernandez Lab uses such data to study patterns of genetic variation, and gain insights into our evolutionary history.  Using detailed simulations and population genetic modeling, we seek to understand the role that natural selection and demography have had on the patterning of variation throughout our genomes.

On-going research:  Population genetic modeling of human populations:

In order to further understand the evolutionary forces that acted on our ancestors, we analyze large-scale sequencing data from populations throughout the world. In collaboration with the 1000 Genomes Project, we employ detailed population genetic models to better understand the implications of complex interactions among evolutionary forces on patterns of genetic variation within and between populations. One current focus is on the implications of a genome's worth of deleterious mutations that are interacting in complex ways to drive systematic genomic patterns of variation. Using detailed simulations and models of background selection, we seek to learn more about our species' history and to discover more of the functionally relevant regions of the genome.

Disease susceptibility in complex populations:

Next-generation sequencing technologies are providing an unprecedented opportunity to learn about the genetic basis of disease. We strive to leverage evolutionary signals in patterns of genetic variation to uncover the meaningful associations with phenotypic variation. One primary focus is in a collaboration with Dr. Esteban Burchard, on the genetics of asthma in minority populations across the USA. By leveraging evolutionary signatures of natural selection and admixture patterns in trans-ethnic studies of Latino and African American populations, we will be able to gain insights into the genetics of this disease for the betterment of all populations.

Host-pathogen interactions

Populations do not evolve in isolation. Rather, they are constantly interacting with other species, both mutualistically (as in the human microbiome) as well as competitively (in the case of pathogens). We are developing tools to leverage patterns of genetic diversity within populations and divergence across phylogenies to learn more about the genetic targets of such interactions. In collaboration with Dr. Nevan Krogan, we are investigating interactions between mammals across the phylogenetic tree and their associated immunodeficiency viruses (e.g., HIV, SIV, FIV, etc). Using both phylogenetic and population genetic techniques, we are learning about the nature of these interactions, and addressing pressing questions about the conditions under which viruses jump species barriers.