Research Interests:
Dr. Lachance uses computational approaches to understand how evolutionary history influences patterns of genetic variation and disease risks in human populations. This research program bridges the gap between evolutionary genomics and genetic epidemiology. Highlights of this work include detecting signatures of archaic introgression in African genomes, the first application of polygenic risk scores to ancient hominins, and the first pan-African GWAS of prostate cancer. His research has also explored why genetic predictions of disease risk generalize poorly across populations, with one key cause being SNP ascertainment bias. To alleviate this bias, he led the successful development of a novel genotyping array that is optimized for detecting genetic associations in populations from sub-Saharan Africa. Working with colleagues from Ghana, Nigeria, Senegal, and South Africa, he has spearheaded efforts to identify continental and sub-continental differences in the genetic architectures of complex traits. Current projects in Dr. Lachance's lab include generating polygenetic risk scores that generalize well across populations and analyzing ancient and modern genomes to uncover the evolutionary history of disease-associated loci.

Teaching Interests:
Dr. Lachance's teaching is focused on population genetics classes at the undergraduate and undergraduate level, including Evolutionary Biology, Mathematical Models in Biology, and Human Evolutionary Genomics. His approach to mentoring is based on maintaining an environment where curiosity and collaboration are valued. Since joining the faculty of the School of Biological Sciences Dr. Lachance has been the primary research mentor of three postdocs and eight PhD students. Awards received by trainees in his lab include an American Indian Educational Fund fellowship, SMBE’s Graduate Student Excellence Award, the Cherry Emerson Research Award, and the O’Hara Graduate Fellowship. Past members of his research group have placed into data scientist positions in industry, academic PhD programs, public health genomics positions at the CDC, and an associate editor position at the journal Science. During his time at Georgia Tech, Dr. Lachance has received the CTL/BP Junior Faculty Teaching Award, a CIOS Honor Roll Award, and been named a Doc Blanchard Professor. He has served eight times as an instructor for the Summer Institute in Statistical Genetics and is currently the director of a Department of Education GAANN training grant.

Recent Scholarly Output:

1. Lauder IH and Lachance J* (2026) Hardy-Weinberg equilibrium and random mating.   Encyclopedia of Evolutionary Biology, edited by Wolf JB and Russo CAM. Academic Press. Vol. 2, pp. 177-182. 
2. Chen F, Sheng X, Wang A, … Lachance J, … Watya S, Conti DV, and Haiman CA* (2025) Integrating Pathogenic Variants, Polygenic Risk Score, and Family History for Prostate Cancer Risk Estimation in Men of African Ancestry. European Urology (accepted). 
3. Janivara R, Hazra U, Pfennig A, Harlemon M, Kim MS, Eaaswarkhanth M, … , Rebbeck TR, Adebiyi AO, Agalliu I, and Lachance J* (2025) Uncovering the genetic architecture and evolutionary roots of androgenetic alopecia in African men.
4. Hoffman T, Graff RE, Madduri RK, Rodriguez A, … Lachance J, Andrews CA, Adebiyi A, Aisuodionoe-Shadrach O, Pedro Fernandez P, Jalloh M, Janivara R, … , Justice AC, Kachuri L, and Witte JSR* (2025) Genome-wide association study of prostate-specific antigen levels in 392,522 men identifies new loci and improves cross-ancestry prediction. Nature Genetics 53:334-344.
5. Rebbeck TR* and Lachance J* (2024) Pan-African analysis identifies genetic differences in prostate cancer risk. Nature Genetics – Research Briefing.
6. Janivara R, Chen WC, Hazra U, Baichoo S, Agalliu I, Kachambwa P, Simonti CN, Brown LM, Tambe SP, Kim MS, Harlemon M, … , Lachance J*, and Rebbeck TR* (2024) Heterogeneous genetic architectures of prostate cancer susceptibility in sub-Saharan Africa. Nature Genetics 56:2093-2103.
7. Brown LM, Elbon MC, Bharadwaj A, Damle G, and Lachance J* (2024) Does effective population size govern evolutionary differences in telomere length? Genome Biology and Evolution 16(5) evae111.
8. Janivara R and Lachance J* (2024) The genetic hitchhiker’s guide to tumor evolution – Chapter 3 in Cancer through Lens of Evolution and Ecology, edited by Somarelli J and Johnson NA. 
9. Hazra U and Lachance J* (2024) Polygenic evolution of germline variants in cancer – Chapter 6 in Cancer through Lens of Evolution and Ecology, edited by Somarelli J and Johnson NA.
10. Wang A, Shen J, Rodriguez AA, Saunders EJ, Chen F, Janivara R, … , Lachance J, … , Kote-Jarai Z, Madduri R, Conti DV, and Haiman CA* (2023) Characterizing prostate cancer risk through multi-ancestry genome-wide discovery of 187 novel risk variants. Nature Genetics 55: 2065–2074 (.pdf). 
11. Pfennig A, Petersen LN, Kachambwa P, and Lachance J* (2023) Evolutionary genetics and admixture in African populations. Genome Biology and Evolution 15(4) evad054.