A Comparison of Effective Population Size (Ne) of Spikedace, Meda fulgida, in Aravaipa Creek, using Population Estimate and Census Methods versus Whole Genomic Inferences.

Authors: Peter Reinthal, Nicolas Alexandre, Alexander Cameron, Thomas Turner, Noah Whiteman

Year: 2021

Abstract

The Effective Population Size (Ne) of a real population is equal to the number of individuals in an ideal population (i.e., a population in which all individuals reproduce equally) that produces the rate of genetic drift seen in the real population. Ne is what matters to the long-term viability of endangered species. Here we use three pass depletion sampling to estimate population size of Spikedace at four locations in Aravaipa Creek that are representative of the area occupied. Population estimates using a maximum likelihood model range estimate populations of 18 individuals/100 meters to 81 individuals/100 meters. The Ne based on census population is much greater (~7X) than Ne estimates from genomic data. Combined with annual census data, we identify the importance of genetic bottlenecks in Spikedace populations.