Image Credit: Kevin Gill, CC BY 2.0, Image Cropped
No consistent effects of humans on animal genetic diversity worldwide (2020) Millette et al, Ecology Letters, https://doi.org/10.1111/ele.13394
As a species, we humans have had enormous negative effects on the planet, and we have talked about many of these issues and how they relate to ecology on many separate occasions here on Ecology for the Masses (see here, here, and here). A key implication of these human-induced changes to our planet are that many organisms are threatened with extinction, which can be bad for us as well (looking at you insect apocalypse).
Having said all of that, a lot of the work that has been done in this area has focused on specific groups (like the charismatic koala). By doing so, we run the risk of not understanding the global pattern but instead draw conclusions based off of local patterns. While we sometimes must make these kind of generalizations, this is not always a good idea. For example, we cannot look at the health of animal populations in New York City and make statements about the entirety of all of the animal populations in North America. To get around that issue, today’s authors investigated, on a global scale, if humans were having a global impact on animal genetic diversity.
Image Credit: Andrew DuBois, CC BY-NC 2.0, Image Cropped
Behavioural fever reduces ranaviral infection in toads (2019) Sauer et al, Functional Ecology, https://doi.org/10.1111/1365-2435.13427
Being infected with a pathogen such as a bacteria or virus can be bad for whatever organism is unfortunate enough to suffer the infection, and sometimes it’s bad enough to kill the host. Because of that, there is a strong pressure to engage in behaviors that reduce the chances of becoming infected in the first place. While these behaviors can be inherited and evolve over time, others take place within the lifetime of the infected individual itself, making it a ‘plastic’ response (see the “Did You Know” from our previous breakdown for the difference between plasticity and evolution).
One plastic response is that of a behavioral fever. In organisms that cannot regulate their own body temperature, like reptiles and amphibians, this behavior involves moving from an area with low temperature to one with a higher temperature, ideally limiting the damage that a pathogen can do or even killing it outright. Because this behavioral fever is so dependent on temperature, it is important to know how climate change may impact emerging infectious disease.
Image Credit: Swallowtail Grass Seeds, Public Domain Mark 1.0, Image Cropped
There has been a lot of recent (and well deserved) press surrounding the bush fires in Australia. Because of these fires countless animal and plant life has been lost, and the most visible example of that are the koalas. You probably saw the video of a woman running into a burning area to save a koala from the fire*. Unfortunately, most of the koalas didn’t have people around to save them and over 1,000 are estimated to have died. Because of this a group has claimed that koalas are now “functionally extinct”, and the press has run with this claim. While it is unfortunate that this misinformation spread so quickly and so widely, the good news is that koalas are in fact NOT functionally extinct. Great! But what does being “functionally extinct” mean?