One of the hottest debates in evolutionary biology concerns the origin of behaviour: is it genetically encoded or do animals and birds copy their parents or other individuals? A classic experiment published in 2000 seemed to provide overwhelming evidence that a particular behavioural choice (whether individuals of a species of swallow breed in a small colony or a large one) is largely genetically determined. Together with colleagues in France, Richard Wagner of the University of Veterinary Medicine, Vienna has re-examined the data and shown that the findings could be explained by random choice. The design of the original experiment – which represents a blueprint for a vast range of studies of heritability of behaviour – contains two pitfalls that combine to undermine the conclusions. The results are published in the journal Scientific Reports.
There are clear advantages to living in cities: safety, ready availability of infrastructure, plenty of company etc. Nevertheless, a large number of people eschew them for the benefits of country life, such as clean air and lots of space. Many species of animals, and particularly birds, face the same choice between living in large groups or remaining in smaller ones, thereby avoiding disadvantages of larger colonies such as the increased risk of disease and increased aggression from neighbours. What causes different individuals of a particular species to take the decisions they do?
It’s all in the genes
One possible explanation is that animals and birds might be genetically influenced to breed in smaller or larger colonies. This idea gained widespread acceptance in 2000, when Charles and Mary Brown reported the results of a field experiment of unprecedented scope.
Read more at: Phys.org