Department of Anthropology
Grandfather’s Age at Reproduction Influences Grandchildren’s Telomere Length: Thrifty Telomeres and Intergenerational Adaptive Plasticity
February 27, 2012
AAG008 5:00 pm
Telomeres are repeating DNA sequences at the ends of chromosomes that protect and buffer genes from nucleotide loss as cells divide. Telomere length (TL) shortens with age in most proliferating tissues, limiting cell division and thereby contributing to senescence. However, TL increases with age in sperm and, correspondingly, offspring of older fathers inherit longer telomeres. Using a large longitudinal study from the Philippines, we show that the effect of paternal age on offspring TL is cumulative across multiple generations: in this sample, grandchildren of older paternal grandfathers at the birth of fathers have longer telomeres, independent of, and additive to, the effect of their father’s age at birth on TL. The lengthening of telomeres predicted by each year that the father’s or grandfather’s reproduction are delayed is equal to the yearly shortening of TL seen in middle-age to elderly adults, pointing to potentially important impacts on health and the pace of senescent decline. This finding suggests an adaptive mechanism by which organisms could extend late life function as average age at reproduction is delayed within a lineage. However, if longer telomeres promote a longer and healthier lifespan, then this begs the question of why natural selection has not resulted in longer telomeres. I suggest that long telomeres are energetically expensive, and that shorter telomeres, while limiting cell repair and replacement abilities to maintain the soma, are metabolically thriftier.
Dan Eisenberg received his BS in anthropology, with a minor in biology and an evolutionary studies certificate from Binghamton University. At Binghamton he began studying molecular genetic determinants of human behavior, particularly attention deficit hyperactivity disorder (ADD/ADHD) from an evolutionary perspective. He is currently finishing his doctorate in biological anthropology at Northwestern University with a focus on studying telomere biology and aging from an evolutionary life history perspective, in collaboration with the Cebu Longitudinal Health and Nutrition Survey in the Philippines. He has done fieldwork in the Bolivian Amazon with the Tsimane’, a group of indigenous forager horticulturalists. In the fall Dan will be moving to Seattle to take up an assistant professor position in the department of anthropology at the University of Washington.