South America's Andean Cordillera offers an unparalleled opportunity to study the adaptive characteristics of hemoglobin proteins that are locally adapted for high-altitude respiration (oxygen pressure is 60% of sea level at 4,000 meters). Hypoxia and natural selection are predicted to have played causal roles in the speciation of waterfowl within the Andes, shaping morphology and subdividing co-distributed subspecies and populations among shared areas of endemism. The population genetics of South American ducks and adaptive characteristics of hemoglobins will be studied across a Megatransect of the Andes. Vouchered specimens will be collected and archived in museum collections. Adult and embryonic a- and b-hemoglobin genes will be sequenced and compared to mitochondrial DNA and nuclear genes that have evolved independently.
This study will bridge a gap between phylogenetic systematics and physiological genetics by studying the population genetics of adaptation. It will provide comparative DNA and amino acid sequence data, including specific information about the amino acid positions that have evolved adaptively in the Andes. This information will contribute to studies of high-altitude physiology and gene expression and erode the long-standing disconnect between history and mechanism and pattern and process in studies of biomolecular adaptation and its role in stimulating biodiversity.
