From humans expanding into new continents to parasites switching into new hosts, how do populations adapt to new environments? How does demographic history shape adaptation, phenotypic variation, and disease risk? We aim to understand how evolutionary and ecological forces shape population variation, and the consequences of biological variation. Work in the Goldberg lab analyses genetic data from multiple species in the context of demographic, archeological, paleontological, and environmental records. We also have a strong interest in theory and methods development. Some ongoing interests are described below.
Evolutionary models of disease
A new line of work in the lab aims to combine population genetics with classic mathematical models of disease transmission. Current work focuses on malaria genetic epidemiology and evolution. Of the ~30 malaria parasites that infect primates, why do only a handful infect humans? How does the complex lifecycle of the parasite influence expected neutral genetic diversity and adaptability? We complement models with genetic analyses to understand host and parasite genetic adaptations, and parasite host-switching across primates.
Genetics of Admixed Populations
Admixture is one of the fastest ways to radically change the gene pool of a population. Admixed populations have been leveraged for the inference of population history, disease association studies, and identification of genomic regions under selection. However, the history of these populations is often more complex than captured by classical models. In particular, there may have been multiple waves of admixture over time, or non-random mating. We develop mechanistic models to study sex-biased admixture and assortative mating in recently admixed populations. Current work includes a collaboration with Sandra Beleza on assortative mating in the admixed population of Cabo Verde. More recently, we have been developing methods to detect recent selection post-admixture, including identifying a signal of adaptation in Cabo Verdeans to malaria over the last 20 generations.
Figure 1 from Hamid et al. 2020. The distribution of West-African-related ancestry across regions of Cabo Verde. The proportion of the population with African-inferred ancestry at the malaria-protective Duffy-negative allele is marked in red is suggestive of selection on the island of Santiago.
Holocene Population Dynamics
The early and middle Holocene was a time of immense climatic and cultural change. We are interested in disentangling the interplay between human & animal demography, the environment, and cultural change, particularly in the Americas. This system can act as an important model for current climate change. Complex processes such as domestication, population expansions, and mass extinctions have far reaching effects and multiple causes. Therefore, incorporating data from multiple sources provides increased resolution. Towards this goal, we are developing methods for demographic inference leveraging archeology, ancient DNA, and modern genetic data.
The figure depicts estimates for human-occupied area across South America from 3 to 2 ka.