Four decades of estimating heritabilities in wild vertebrate populations: improved methods, more data, better estimates?

Abstract

Abstract After over four decades of attempting to disentangle the role of genetic and the various sources of environmental variation in natural populations, what has been learned about the absolute and relative role of genes and the environment in shaping phenotypic variation? This chapter explores how new methodological developments, and the application of the animal model in particular, have changed and shaped quantitative genetic studies of natural populations. In particular, this chapter assesses i) whether the estimates of absolute and relative amounts of genetic and environmental variation, as well as their accuracy, are affected by the method employed (e.g. parent–offspring regression vs animal model), ii) whether they have changed over time, and iii) if they have, what are the causes of these changes. A literature search was performed to find studies that estimated heritabilities, with the search limited to estimates based on individual-based data on free-living vertebrate populations. This resulted in a database containing over 1600 heritability estimates, for a wide range of species and traits, and estimated using a variety of methods. Using these data, this chapter goes on to show how heritabilities are being estimated for an increasing number of traits, and that these heritabilities have become more accurate and probably less biased over time, but that heritability estimates for individual traits have changed remarkably little. The implications of these findings for the understanding of the generation and maintenance of the ubiquitous amounts of variation present are discussed, and suggestions for future research are made.