Body coloration of an animal can be useful for not only attracting prey, but also avoiding being eaten. One important question is whether or not this coloration can simultaneously serve both purposes? (Image Credit: Chen-Pan Liao, CC BY-SA 3.0).
Multifunctionality of an arthropod predator’s body coloration (2019) Liao et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13326
One topic that has interested ecologists for decades is that of animal body coloration, and what function that coloration can serve for the animal. Despite this fascination and the work that has been done to study this aspect of animal biology, the actual mechanisms driving the evolution and maintenance of body color are not well understood. Many different aspects of an organism’s life can shape and affect body color, such as avoiding predators, attracting mates, and whatever resources an organism has available to create specific colors. In addition, many of these aspects often compete with one another, such that a color that is good for attracting mates may also make you more easily-spotted by a predator.
Spiders provide an excellent system in which to study the evolutionary significance of body colors, as previous work has shown that body color affects mate attraction, predator avoidance, and prey attraction. The authors of today’s study wanted to know if these complex color patterns could serve more than one function in the spider’s life.
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
Image Credit: Dag Hessen, University of Oslo
The past couple of years has seen younger generations become increasingly active with regards to environmental change. Recent protests worldwide, spearheaded by people like Greta Thunberg, have been incredibly encouraging to watch. So it’s important that scientists continue to improve our ability to communicate science to children.
On that note, I spoke to Dag Hessen, Norwegian ecologist and writer, who has published several science books, also successful children’s books. We spoke about the importance of explaining ecological concepts to children, the process of writing a book, and dealing with a different form of writing.
Image Credit: Thomas Haaland, CC BY-SA 2.0
Previously on this site I’ve summarised an article I wrote linking some concepts from behavioral ecology with evolutionary biology. Now I’m back to say a bit more about what behavioral ecology actually is. Being introduced to the field of behavioral ecology was what sparked me to actually consider a career in science. It’s a fascinating and beautiful field, and I hope I can show you why!
Natural selection favors a larger eye in response to increased competition in natural populations of a vertebrate (2019) Beston & Walsh, Functional Ecology, doi: 10.1111/1365-2435.13334
Studying the evolution of traits in response to selection pressure often helps us understand why species look and act the way they do. Selection pressure can include the need to find food before other members of your species, or the need to escape predation.
But what happens when improving your ability to obtain resources also means you’re more vulnerable to predation? Which will win out? This paper looks at a small species of freshwater fish, Rivulus hartii, and determines which of the two pressures contributes most to the evolution of the size of their eye.
Modeling the ecology and evolution of biodiversity: Biogeographical cradles, museums, and graves (2018) Rangel et al., Science, 244, DOI: 10.1126/science.aar5452
Understanding the processes which drive biodiversity worldwide is never more crucial than now, in a world where biodiversity is shrinking rapidly. Biogeography, the study of species distributions, has come a long way, but there are still a lot of problems that need solving, including improving our understanding of the interactions between factors like climate change, dispersal abilities, fragmentation and species competition, to name a few.
This paper attempted to analyse some of the effects of those factors in concert, by producing a simulation of the evolutionary process in the world’s most biologically diverse continent, South America.
Host defense triggers rapid adaptive radiation in experimentally evolving parasites (2019) Bush et al., Evolution Letters, p. 1-9
Adaptive radiation is a fascinating ecological concept, one with which anyone who knows the tale of Darwin’s finches will be familiar with. The basic premise is that an organism may evolve different forms (and ultimately become different species) in response to pressures exerted upon them.
But whilst this may have been observed in many vertebrates, it’s often overlooked in parasites, whereby host defenses can prompt divergence in parasite morphology. Today’s paper wanted to test the two basic concepts of evolution. 1) Can host defenses prompt physical changes in parasites? 2) Are these changes heritable?