Animals rarely avoid inbreeding

Published on
May 4, 2021

The widespread general assumption is that inbreeding is bad for genetic reasons and something that should be avoided under all circumstances. A new meta-study performed by researchers at Stockholm University and Wageningen University & Research shows that there is little support for the view that animals should and if possible, automatically do avoid inbreeding. The study is published in the scientific journal Nature Ecology & Evolution.

The findings settle the longstanding debate between theoretical and empirical expectations about if and when animals should avoid inbreeding. 'We address the 'elephant in the room' of inbreeding avoidance studies by overturning the widespread assumption that animals will avoid inbreeding whenever possible', says Assistant Professor Alexander Kotrschal of Wageningen University & Research, one of the senior authors of the study. 

Hundreds of years of experiments

The study provides a synthesis of related literature on the subject and evaluates 139 experimental studies in 88 species spanning 40 years of research. Kotrschal: 'Together hundreds of years of experiments that we systematically analyzed'.

There are several possible explanations why animals consider inbreeding not a bad idea. Inbreeding might be the best option in comparison to other possibilities, or maybe the downside is not too big. 'And sometimes inbreeding can even be advantageous', says Kotrschal. 'Think about animals completely adapted to their local environment for example'.

Conservation Biology

The findings of this study published in the scientific journal Nature Ecology & Evolution will have wide reaching implications for conservation biology. Mate choice is increasingly being used in conservation breeding programs in an attempt to the success of ex situ (outside the habitat) conservation efforts for endangered species.

'A primary goal of ex situ conservation efforts is to maintain genetic diversity, and free mate choice is generally expected to achieve this goal. Our findings urge caution in the application of mate choice in ex situ conservation programs', says assistant professor John Fitzpatrick of Stockholm University.​