19 August 2020

The social structure of populations and the impact on genetic diversity

Golden-crowned sifaka (Propithecus tattersalli) © Erwan Quéméré

A team of researchers from Instituto Gulbenkian de Ciência (IGC) demonstrated that considering the social structure of some animal populations is crucial to understand the maintenance of their genetic diversity.

Besides having a spatial structure, vertebrates can be organized in social groups that range from temporary pairs of individuals to complex hierarchies. Some social organizations imply mating between genetically close individuals, also known as inbreeding. This can decrease genetic diversity and increase in the prevalence of harmful genetic combinations.

The study published in the journal Heredity focuses on a species of lemur from Madagascar, the golden-crowned sifaka (Propithecus tattersalli), one of the most emblematic and currently endangered with extinction, and shows that social structure can maintain high levels of genetic diversity without the need for inbreeding avoidance.

The team of researchers led by Lounès Chikhi proposed a new computational model that explicitly models social structure, contrary to currently existing population genetics models that tend to ignore it. Their results show that the genetic diversity described in sifakas in nature can be reproduced by the model when inbreeding-avoidance mechanisms are not considered.

This study highlights the importance of social structure to understand the genetic diversity of endangered species and, in the context of the current global environmental crisis, provides important perspectives to save them from extinction.

Know more about this research in the article published by the first author of this study, Bárbara Parreira, in Nature Ecology & Evolution’s blog.

 

Read the scientific article