Fur colour in the Arctic fox: genetic architecture and consequences for fitness (2021) Tietgen et al., Proceedings B, https://doi.org/10.1098/rspb.2021.1452
Researchers who try to understand the dynamics of wild populations often look at how different traits affect the survival and reproduction of different individuals within those populations. Usually, the investigated traits are visible and easy to observe, like an animal’s size or their colour. However, there may be cases where the important traits are not as conspicuous or even hidden behind more striking features.
The arctic fox (Vulpes lagopus) occurs with two distinct fur colours, often called morphs. The two most common are the white morph and the blue morph. Which of these morphs is more common depends on the population. In Norway, the white morph is more common but in recent years an apparent increase in foxes of the blue morph has been observed. Previous research has shown that blue arctic foxes are usually fitter, but until now there hasn’t been a good explanation of why.
We wanted to dive a little bit deeper into the differences between the two colour morphs, explore the genetics behind this trait and seeing whether we could find any “hidden” traits connected to fur colour that could explain the difference in fitness between the two morphs.
Ant collective behavior is heritable and shaped by selection (2020) Walsh et al., The American Naturalist, https://doi.org/10.1086/710709
Image Credit: Землеройкин, CC BY-SA 4.0
Working together to achieve a common goal is nothing new to us. We as humans are famously social organisms that not only crave interactions with others, but quite often succeed due to the way that we work together. Interestingly, we tend to work well when we have some form of organizations or leadership, but there are other animals that do not require such leadership. This so-called “collective behavior” is the behavior of a group that emerges without a form of central control. Think of a large school of fish avoiding a predator at the same time, or birds flocking together and flying through the sky. All of this happens as a result of those animals interacting with one another, not because there is some boss animal telling them to do it.
Not surprisingly, groups of animals will vary in their exact method of collective behavior. It’s assumed that this variation is largely dependent on natural selection, but there isn’t actually much that is known about it. For this variation in behavior to have been the result of natural selection, the variation itself has to be advantageous and heritable, meaning that it is better to have the variation and you can then pass it on to your offspring. Today’s authors wanted to measure just that.