Image Credit: Kevin Pluck, CC BY 2.0, Image Cropped
Brain expansion in early hominins predicts carnivore extinctions in East Africa (2020) Faurby et al, Ecology Letters, https://doi.org/10.1111/ele.13451
We’ve covered humans and their harmful effects many times here on Ecology for the Masses (see my recent breakdown from last month). Despite all of the colorful examples of our current effects on the wildlife of our planet, a significant amount of research has implicated Homo sapiens as the driver of the extinction of some of the megafauna of the prehistoric world, events that happens millions of years ago. Another possibility is that we as organisms (hominins, not Homo sapiens specifically) have been impacting other species for a very, very long time.
Today, East Africa is home to the most diverse group of large carnivores on the planet (though it is still less diverse than what was once seen in North America and Eurasia). Millions of years ago East Africa had an even more diverse assemblage of large carnivores, including bears, dogs, giant otters, and saber-toothed cats. The change in climate since that time may have caused the decline in large carnivore diversity, but another explanation is the rise of early hominins (our ancestors). Using fossil data, the authors of today’s paper wanted to figure out if it was indeed early hominins that drove many large carnivores extinct.
Image Credit: Manfred Antranias Zimmer, Pixabay licence, Image Cropped
Invasion of freshwater ecosystems is promoted by network connectivity to hotspots of human activity (2019) Chapman et al., Global Ecology and Biogeography, https://doi.org/10.1111/geb.13051
The spread of invasive species throughout freshwater ecosystems is a topic we’ve looked at before on Ecology for the Masses. In a previous paper breakdown we talked about how recreational is heavily responsible for the presence of non-native fish at a European scale.
Our paper this week takes a more local approach. Can we predict the presence of non-native birds, invertebrates and fish by looking at the presence of human activity, and where that human activity is present?
Increased urbanisation may have a negative effect on the richness of moth species like this Vine’s Rustic, but it depends on what scale we consider richness (Image Credit: Patrick Clement, CC BY 2.0, Image Cropped)
Urbanization drives cross-taxon declines in abundance and diversity at multiple spatial scales (2019) Piano et al., Global Change Biology, https://doi.org/10.1111/gcb.14934
You would think that the effect of building a whole lot of stuff on something’s habitat would have a negative effect on just about anything. But building a whole lot of human stuff (maybe let’s retain a modicum of science-ness and call it urbanisation) hasn’t always been shown to be necessarily bad for species. There are a lot of studies out there which show that urbanisation is can be a negative for biodiversity (which makes sense, since for starters it generally breaks up habitat patches and introduces a whole lot more pollutants). But there are also studies showing that urbanisation can increase biodiversity.
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: Elliott Brown, CC BY 2.0, Image Cropped
Making Brexit work for environment and livelihoods: Delivering a stakeholder informed vision for agriculture and fisheries (2019) Beukers-Stewart et al., People and Nature, https://doi.org/10.1002/pan3.10054
Ok, last article on Brexit for the time being. Everyone rest easy. This week’s paper looks once again at the consequences of Brexit for both the agricultural and fishing industries, and the knock-on effects on Britain’s farmland and marine ecosystems. As has been echoed both by this week’s earlier interview with Abigail McQuatters-Gollop and the views from this week’s British Ecological Society Annual Meeting, Brexit can represent an opportunity. An opportunity to put together a directive that helps maintain both marine and terrestrial ecosystems whilst not putting the people at a disadvantage.
This week’s paper is trying to get an understanding of how to put together that framework, by speaking to the people Brexit will likely impact more quickly than others: farmers and fishers. Government subsidies support many British farmers, and it’s not clear whether they’ll remain in place going forwards. Quotas could shift dramatically for fishers.
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: Aravindhanp, CC BY-SA 3.0, Image Cropped
City life alters the gut microbiome and stable isotope profiling of the eastern water dragon (Intellagama lesueuriii) (2019) Littleford-Colquhoun, Weyrich, Kent & Frere, Molecular Ecology, https://doi.org/10.1111/mec.15240
It’s a pretty fair call to assume that if you build a city on a species’ habitat, it might be a little miffed. Yet as human settlements expand worldwide, many species are showing that they’re able to make rapid changes to their biology to adapt to living around humans.
This includes their diet, of course. As diets shift, many other aspects of a species’ biology follows, including the microbes that live in a species’ gut. And gut microbes influence a huge range of factors, including immunology, development, and general health. The response of a gut microbe community (the gut microbiome) to a new diet can in turn affect an animal’s ability to adapt to that environment.