Deer mice like the one above are small parts of a complex and interconnected world. When two pieces of their world work against them simultaneously, how are these mice affected? (Image Credit: USDA, CC BY 2.0).
Botfly infections impair the aerobic performance and survival of montane populations of deer mice, Peromyscus maniculatus rufinus (2019) Wilde et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13276
Parasites are bad news for the organisms that host them. Some parasites are so bad, they can actually make the host kill itself. Despite these clear and obvious costs to infection, the common consensus is that parasites are not too big of a deal for the host, because of how rare parasitic infection is on average. For example, in my research system only one in ten animals have parasites.
But when these ill-effects of parasitism are combined with other detrimental factors, such as a harsh environment, an organism with parasites is forced to deal with not one but two stressors. The authors of today’s paper were interested in how these effects of parasites may change depending on the environment that the host lived in.
In nature, it often pays to blend in to your background, especially if you’re a prey species like the deer mice used in this study. (Image Credit: Gregory Smith, CC BY-SA 2.0, Image Cropped)
Linking a mutation to survival in wild mice (2018) Barret et al. Science, 363, p. 499-504.
A big part of ecological studies involves investigating how certain traits or behaviors work (adapted) or don’t work (maladapted) in a specific environment, while scientists who study genetics may investigate specific parts of the DNA that are under selection for specific values of a given trait. Surprisingly, not many studies investigate these two aspects of natural selection simultaneously, instead they will attribute selection to a specific trait value without knowing the genetic mechanisms behind it.
The authors of this study used a well-studied model system of deer mice (Peromyscus maniculatus) to link these two aspects of ecology together, tying a mutation in a gene that codes for coat color into selection in the wild. The study took place in the Sand Hills of Nebraska, a relatively young region (in geological terms) where these mice are expected to have recently adapted to the environment due to strong selection for traits that promote their survival.