Nieuws
A bit of variation leads to better survival in great tit birds
Great tit birds grown up in nests with some variation in fledging weight have better survival and reproductive success. So, a bit of within-family variance seems to have an evolutionary advantage. Researchers from Wageningen UR and NIOO-KNAW found significant genetic variance in within-family variation of fledging weight of Great Tits (Parus major) and found evidence for stabilizing selection on the within-family variation. Studying genetic control and evolution of within-family variation will increase our understanding of evolution of variances and the role of differences in within-family variation for adaptation to changing environments.
Han Mulder from Animal Breeding and Genomics Centre and Philip Gienapp and Marcel Visser from NIOO-KNAW published their study in Evolution. In their study they analysed fledging weight and its within-family variance of chicks of Great Tit at the Veluwe. They found significant genetic variance in within-family variance, i.e. the variability of chicks in one nest. Fledging weight is the weight of the chick just before the chicks leave the nest. The researchers found that parents with nests with a small or high variation have fewer offspring that survive and reproduce in the next year, while parents with an intermediate variation have more offspring surviving and reproducing. This means that there is evidence for stabilizing selection on the within-family variance. This is one of the very first studies studying the genetics of phenotypic variability and its evolution in a natural population. Such studies can help us to increase our understanding of evolution of variances and the role of differences in within-family variation for adaptation to changing environments.