This Peruvian warbling-antbird must walk a fine line between being different enough from its competitors to reproduce successfully, while staying similar enough to be able to recognize and outcompete the same competitors (Image Credit: Hector Bottai, Image Cropped, CC BY-SA 4.0).
Range-wide spatial mapping reveals convergent character displacement
of bird song (2019) Kirschel et al., Proc B, https://dx.doi.org/10.1098/rspb.2019.0443
In nature, many different organisms can be found in a single location, and sometimes those organisms are closely related to one another. When this happens, classical evolutionary theory predicts that these closely related species should differ in some ways, so as to differentiate members of their own species from others and avoid the costs associated with breeding with a mate that will not produce any viable offspring. This is called character displacement, and there are many examples of this in nature where two different species may be very similar when they live in different places (allopatry), but when they live in the same place (sympatry) they will differ in appearance, behavior, or the exact part of the local habitat that they live in (see Niche Partioning below).
A specific form of character displacement, called agonistic character displacement, occurs when traits or behaviors associated with competition differ between closely related species living in the same area. This is thought to reduce the costs of wasting energy on competing with an organism that you don’t really “compete” with. Agonistic character displacement can, however, result in greater similarity of traits when similar species live together, but previous studies in this area have not accounted for other causes of this similarity. Today’s authors wanted to do just that. Read more
American politicians Alexandra Ocasio-Cortez and Ed Markey, champions of the controversial environmentalist bill, the Green New Deal (Image Credit: Senate Democrats, CC BY 2.0)
If you’ve lost track of what’s going on in US politics (very excusable), you might have missed out on yet another issue that is dividing people. I’m not talking about the Mueller report, or gun legislation, or health care. I’m talking about the Green New Deal, named after the New Deal, a compilation of programs and projects that gave Americans jobs after the Great Depression and built quite a lot of infrastructure. The newest “Green” version is meant to do the same following the Great Recession that America has been suffering the aftershocks of since late last decade. An initiative sponsored by Democrats, the Green New Deal has come under fire from both sides for a wide range of reasons. While the movement for action against climate change is a global phenomenon, I am going to give a brief synopsis of what the Green New Deal represents in the US, and why it has been the subject of so much controversy.
The red lionfish, an aggressive, fecund, and competitive species invasive to the Atlantic Ocean (Image Credit: Alexander Vasenin, CC BY-SA 3.0).
The genomics of invasion: characterization of red lionfish (Pterois volitans) populations from the native and introduced ranges (2019) Burford Reiskind et al., Biological Invasions, https://doi.org/10.1007/s10530-019-01992-0(0123456789
Invasive species are one of the most destructive forces and largest threats to native ecosystems, second only to habitat loss. The “how” and “when” of a species invading new habitats is obviously important, and as such many studies focus on if invasive species are present and if they are spreading. Yet these studies often disregard the mechanisms behind why a species is spreading or succeeding in these new environments. The mechanisms are important here, because by and large most invasive organisms will have very small populations sizes, leaving them vulnerable to stochastic events like environmental flux, disease, and inbreeding depression.
Two key paradoxes of invasive species are that these small groups of invasive organisms tend to not only have more genetic diversity than the native species (making them more adaptable to environmental change), but they are also able to outcompete the native organisms, despite having evolved in and adapted to what may be a completely different environment. The authors of this study used genomic approaches to address and try to understand these paradoxes. Read more
Many organisms are vulnerable to a wide array of diseases and parasites throughout the course of their lives, but could scavengers help reduce that vulnerability? (Image Credit: The High Fin Sperm Whale, CC BY-SA 4.0)
Do scavengers prevent or promote disease transmission? The
effect of invertebrate scavenging on Ranavirus transmission (2019) Le Sage et al., Functional Ecology, https://doi.org/10.1111/1365-2435.13335
As intimate as the host-parasite relationship is, it is important to keep in mind that it is embedded within a complex web of other interactions within the local ecological community. To add to this complexity, all of these interactions can feed back on and effect the host-parasite relationship. One ubiquitous part of all communities is the scavenger, an organism that feeds on dead and decomposing organisms. The authors of this paper wanted to investigate how scavengers affect disease transmission in local communities.
This question in interesting because it can easily go either way, depending on the community in question. Scavengers could lower disease transmission by eating infected organisms, thus removing contagious elements from the environment. However, scavengers could also increase transmission by promoting the spread of contagious elements in the community via their own waste after they consume infected tissues.
We examine the ecology of the BGWMs of 2011’s Attack the Block. Sexual ecology has never been more furry. Or glow-in-the-dark. Actually sexual ecology can get pretty furry. Also we have two fights this week.
3:05 – The Chimera in Cinema
11:41 – Ecology of a BGWM
38:38 – BGWMs vs. Liam Neeson from The Grey
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