Doctoral Dissertation Improvement: Landscape Genetics of Gibbons and Leaf Monkeys in China

Washington University, Saint Louis MO

Investigators

Abstract

How geographic boundaries interact with primate locomotion and ecology to fragment populations, form new species, and lead to their extinction remains a fundamental question for biological anthropologists. Little effort has been made, however, to ascertain precisely how subtle geographic variation actually modifies the underlying population genetic relationships of primates in a changing environment. As human-induced environmental degradation continues to isolate and fragment dwindling populations of primates, it has become critical to understand how innate biological factors influence the ability of primates to disperse through and exchange genes within these variable environments. Black crested gibbons (Nomascus concolor) and Phayre's leaf monkeys (Trachypithecus phayrei) have overlapping habitats in many parts of Yunnan, China, but it is unclear how their biological differences (in ecology, locomotion, etc.) affect their abilities to overcome the geographic barriers imposed by both a naturally diverse landscape and one actively modified by humans. Research conducted by doctoral student Joseph Orkin (Washington University in St. Louis), under the supervision of Dr. Richard Smith, examines how the same geographic boundaries (mountains, forest structure, and rivers) affect the capability of these distinct, endangered primates to disperse and exchange genes. By comparing paired populations of two declining species that have been simultaneously fragmented within the same variable habitat, the research tests the hypothesis that these differences in locomotion and ecology are affecting both the evolution and survival of gibbons and leaf monkeys. The research provides a robust, new understanding of the interacting causes of population fragmentation, and yields real conservation impacts. By forging new, long-term collaborative ties between the American and Chinese primatological communities, it also provides a mutual sharing of knowledge and experience to help maintain biodiversity in a critical region.