Mitogenome evolution in the last surviving woolly mammoth population reveals neutral and functional consequences of small population size

Isolation on Wrangel Island led to the fixation of deleterious genetic mutations in the last surviving woolly mammoth population, likely due to strong genetic drift in a small population. The study analyzed high-quality mitogenomes from 21 radiocarbon-dated woolly mammoths, comparing the ancestral Late Pleistocene Siberian population with the Holocene Wrangel Island population. Findings revealed that mitogenome diversity was reduced to a single haplotype at isolation, indicating the Holocene population was established by one maternal lineage. Additionally, mutation rates suggest an accelerated evolutionary rate in the isolated population, supporting the hypothesis that purifying selection becomes less effective in small populations.

Pečnerová, P., Palkopoulou, E., Wheat, C. W., Skoglund, P., Vartanyan, S., Tikhonov, A., Nikolskiy, P., van der Plicht, J., Díez-del-Molino, D., & Dalén, L. (2017). Mitogenome evolution in the last surviving woolly mammoth population reveals neutral and functional consequences of small population size. Evolution Letters, 1(6), 292–303. https://doi.org/10.1002/evl3.33