Tag Archives: mutualism

Always There for You

Evolution and maintenance of microbe-mediated protection under occasional pathogen infection (2020) Kloock et al., Ecology and Evolution, https://doi.org/10.1002/ece3.6555

Image Credit: Zeynep F. Altun, CC BY-SA 2.5, Image Cropped

The Crux

Microbes are everywhere in nature, and I don’t just mean out in the wild. They live inside of every plant and animal, including humans. These microbes can be harmful, beneficial, or do nothing to their hosts. When they help us, microbes take part in what’s called “defensive mutualism”, which is where they help their hosts fight off parasites. Benefiting from this mutualistic relationship depends on whether or not there are parasites around to defend against, as microbial defense mechanisms can harm not only the parasite but also the host itself.

For this symbiotic relationship to continue and not be selected against over time, the benefits of hosting the microbe must outweigh the costs. This is all well and good when there are always a lot of parasites to defend against, but that is not always the case. Today’s authors wanted to test how changes in parasite pressure over time affected the relationship between a defensive microbe and its host.

Read more

It Pays to Break from the Crowd

Image Credit: Pete, CC BY-NC 2.0

Increased reproductive success through parasitoid release at a range margin: Implications for range shifts induced by climate change (2020) MacKay, Gross, & Ryder, Journal of Biogeography, https://doi.org/10.1111/jbi.13795

The Crux

Predicting the response of organisms to climate change is a challenge for ecologists and wildlife managers alike. Fortunately, some responses are common enough that it is still possible to make fairly accurate predictions about them without too much information. One common response is that of the range shift, whereby a population of organisms facing some alteration (eg. climate change) in their current habitat, making it unfavorable, begin to move to another location. This allows them to track favorable environmental conditions and possibly mitigate any negative effects of climate change.

Sounds easy, right? Just pack it all up and move when things get hard? Well, for some organisms it may be that simple (looking at you, birds), but for others (like trees) it is significantly harder to do so. Trees (and other plants) are limited in that they depend on other organisms or things like wind to help disperse their seeds. Making things even more difficult are plant species that depend on specific pollinators, and in order for a successful range shift to happen trees AND their pollinators have to make the move. Today’s authors wanted to study how relationships between trees and their pollinators changed at the leading edge of a range shift, allowing them to understand how and why trees succeed during a range shift.

Read more