RAPID: Preserving Primate Data to Investigate the Relationship Between Skeletal Shape and Hybridization

University Of California-Davis, Davis CA

Investigators

Abstract

Hybrids are the offspring of two different species or varieties of a plant or animal. Recent genetic evidence suggesting that our hominin ancestors interbred with other hominin species has highlighted hybridization in our own evolutionary past. If there are predictable patterns in hybrid skeletal shape, it might be possible to identify evidence of hybrids in the hominin fossil record, for which genetic data are not always recoverable. A good way to determine whether such patterns exist is to study hybrid skeletal shape in species that are closely related to humans. This project will preserve hybrid macaque (monkey) skeletons and related imaging, genetic, and life history data that would provide excellent comparative data on hybridization, but that are at immediate risk of being lost. The monkeys are part of a hybrid macaque colony (Chinese and Indian Macaca mulatta) that is no longer being expanded and is therefore declining in size as individual animals die. If the monkeys' skeletal data are not preserved after death, and normally they are not, this valuable resource to understand hybridization will be lost. This study will benefit the scientific community by producing a curated research collection of hybrid skeletal remains and associated data. It will also support international collaborations and student mentorship and training. Recent evidence of gene flow among archaic human lineages has brought admixture to the forefront of anthropological and public interest. This study will develop principled criteria for detecting skeletal evidence of admixture, using a model organism that is closely related to humans. Specifically, the RAPID award will allow for postmortem preservation and scanning of approximately 80 macaque hybrids from the California National Primate Research Center (CNPRC), starting immediately, so that their skeletons and related data can become part of a valuable collection used to address hybridization and other research topics. Attrition in the hybrid macaque colony is high, and a representative sample of the colony (in terms of hybrid status) may not be possible to acquire if individual animals are not preserved starting now. The investigators plan to use the resulting skeletal collection (estimated n=200) to quantify and model hybrid phenotypic variation, evaluate discriminant functions to distinguish hybrids from non-hybrids, and develop models for detecting hybridization in hominins and other taxa on the basis of skeletal phenotype. Large, genotyped primate samples of known pedigree are very rare. The skeletal sample and associated data will be curated at UC Davis and made available to other researchers. The collection and related research questions are likely to be of interest in disciplines including primatology, biology, zoology, and quantitative genetics.