What Determines Levels of Mitochondrial Genetic Diversity in Birds?

What determines levels of genetic diversity in mitochondrial DNA remains unresolved. We have investigated the factors that are correlated to the level of synonymous diversity of mitochondrial DNA in more than 300 bird species. We find that diversity is significantly correlated to clutch and range size, but not significantly correlated to many other variables including body mass, latitude, and longevity. The correlation between diversity and range appears to be a consequence of a correlation between range and effective population size since a measure of the effectiveness of natural selection, which is expected to be correlated to the effective population size, is also correlated to range. The slope of the relationship between diversity and range is shallow, consistent with Lewontin's paradox, and very similar to the relationship found in mammals.

Automated summary

We examined the factors influencing synonymous diversity of mitochondrial DNA in over 300 bird species. We found that diversity was significantly associated with clutch and range size, but not with other variables such as body mass, latitude, and longevity. The correlation between diversity and range size seems to be a result of the relationship between range size and effective population size, as a measure of the effectiveness of natural selection, which is expected to be correlated with effective population size, is also correlated with range size. The slope of the relationship between diversity and range size is shallow, consistent with Lewontin's paradox, and similar to the pattern found in mammals.