Tag Archives: evolution

Biotic Interactions: Not All They’re Cracked Up to Be?

Image Credit: Danyell Odhiambo/ICRAF, CC BY-NC-SA 2.0

Local Adaptation to Biotic Interactions: A Meta-analysis across Latitudes (2020) Hargreaves et al., The American Naturalist, https://doi.org/10.1086/707323

The Crux

Local adaptation is a process whereby individuals native to a given area are better-suited to live in that environment than foreign individuals, and those local individuals will out-compete foreign individuals. This adaptation to local conditions can range from a predator that is better at finding and catching prey, to a plant that is more efficient than another at taking nutrients from the soil, or to a host that has evolved defenses against a local parasite. Despite a wealth of literature and science that has been dedicated to the study of local adaptation, it is not clear what it is about the environment that commonly drives it.

Early studies of local adaptation measured abiotic (non-living) factors like temperature and the amount of light, but this ignores the fact that all environments include biotic factors like other species and any interactions with them. A small amount of studies have shown that biotic interactions (i.e. interactions with other species) can drive local adaptation, but there isn’t a consensus on how common of a pattern that is. Today’s authors used a meta-analysis of previous studies to test how these biotic interactions affect local adaptation. Read more

How Form Defines Function

Image Credit: Francesco Veronesi, CC BY-SA 2.0, Image Cropped

Macroevolutionary convergence connects morphological form to ecological function in birds (2020) Pigot et al, Nature Ecology & Evolution, https://doi.org/10.1038/s41559-019-1070-4

The Crux

There are an astounding amount of different forms that the animals on our planet take. Likewise, there are a multitude of diverse functions that animals serve in the environment, such as that of a herbivore, a predator, or scavenger. In some cases it’s a clear link between the form of a given animal and its function in the environment, like that of the beak of a hummingbird that allows it to feed on nectar and their role as a pollinator. But whether or not there is a reliable way to predict the function of an animal based off of its form is has been the subject of considerable controversy.

Deciding on how many morphological traits to use to predict ecological function is a difficult prospect. One could argue that it’s impossible to pick a finite number of traits, as there are infinite possible niches that organisms can fill so there’s no way that a set of traits could fill those infinite possible niches. Mapping animal form to function has major implications for quantifying and and conserving biodiversity, and the authors of today’s paper wanted to to determine just how many traits are needed to do that.

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Dragon Guts in the City

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

The Crux

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.

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Adapt or Die

Mandt’s Black Guillemont (Image Credit: Óskar Elías Sigurðsson, CC-BY 2.0, Image Cropped)

Phenotypic plasticity or evolutionary change? An examination of the phenological response of an arctic seabird to climate change (2019) Sauve et al., Functional Ecology, https://doi.org/10.1111/1365-2435.13406

The Crux

If you’re here on Ecology for the Masses, then you know that climate change is not only real but is causing all kinds of problems for organisms the world over. One of the things that climate change is doing is altering seasonality, the time of year in which a given season will take place. For example, where I live in the US, it is normally cold at this time of year, but as I write this it is 60F/16C, much warmer than it should be despite it almost being winter. These changes can affect when organisms start their seasonal breeding, but how these breeding events change is not always the same.

Some changes are due to evolution, or the change in a population’s gene frequencies over time. As mutations and selection take place, a given population may have some traits or behaviors selected for over others. Another way that these changes can happen is via plasticity, which is a change induced by the environment, but without changing the gene frequencies (See Did You Know? for more information). The authors of today’s paper wanted to know if the change in breeding dates of a colony of seabirds (Mandt’s black guillemont, Cepphus grylle mandtii) was due to evolution or plasticity.

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Whales Are Fish: Weird Perspectives on Classification

You would think that after researching how a species will react to climate change, which individuals are more likely to avoid predators, and what its DNA says about its evolutionary history, simply classifying what species an animal is would be pretty simple. Unfortunately that’s not the case. I distinctly recall being given the runaround by my primary school teacher when asked to define what a mammal was (according to the internet a coconut qualifies, so maybe that debate’s not over yet).

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Explaining Evolution: Lessons from Friends

Image Credit: Friends, 1995

Yes, I watched Friends as a kid. Yes, I know it’s a comedy show. Yes, I loved it. Yes, I know it had serious problems in it’s depiction of a few minorities. Yes, I know Phoebe is a ball of whimsy and Ross is a condescending jerk. But I run a podcast called Cinematica Animalia and I’m an avid science communicator, so I want to talk about this scene, and what it potentially teaches us about how to talk about science.

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To Blend in or Stand Out?

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 LiaoCC BY-SA 3.0, Image Cropped).

Multifunctionality of an arthropod predator’s body coloration (2019) Liao et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13326

The Crux

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.
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