Author Archives: Adam Hasik

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

The How and Why of Climate-Mediated Extinction

Image Credit: Dreamy Pixel, CC BY 4.0

Recent responses to climate change reveal the drivers of species extinction and survival (2020) Román-Palacios & Wiens, PNAS, https:/doi/10.1073/pnas.1913007117

The Crux

We tend to think of climate change as bad, and despite the fact that some organisms will benefit from it, many others won’t. A big part of why we consider it bad is that species are predicted to be lost at an alarming rate, with some estimates as high as 54% of all organisms going extinct. An issue with these predictions is that they tend to assume that species will track their preferred temperature and precipitation conditions, but this eliminates any ability of organisms to adapt to their new normal over time.

Today’s authors wanted to use data from previous studies to estimate how species adapt (or don’t) to climate change. Although previous work has shown that climate change is detrimental for many species, this study aimed to learn if it was due to changes in the overall temperature, changes in the extremes (i.e. how hot the hottest day is), or was it the sheer speed of change that did organisms in. Read more

It Pays to Break from the Crowd

Image Credit: Pete, CC BY-NC 2.0

Increased reproductive success through parasitoid release at a range margin: Implications for range shifts induced by climate change (2020) MacKay, Gross, & Ryder, Journal of Biogeography, https://doi.org/10.1111/jbi.13795

The Crux

Predicting the response of organisms to climate change is a challenge for ecologists and wildlife managers alike. Fortunately, some responses are common enough that it is still possible to make fairly accurate predictions about them without too much information. One common response is that of the range shift, whereby a population of organisms facing some alteration (eg. climate change) in their current habitat, making it unfavorable, begin to move to another location. This allows them to track favorable environmental conditions and possibly mitigate any negative effects of climate change.

Sounds easy, right? Just pack it all up and move when things get hard? Well, for some organisms it may be that simple (looking at you, birds), but for others (like trees) it is significantly harder to do so. Trees (and other plants) are limited in that they depend on other organisms or things like wind to help disperse their seeds. Making things even more difficult are plant species that depend on specific pollinators, and in order for a successful range shift to happen trees AND their pollinators have to make the move. Today’s authors wanted to study how relationships between trees and their pollinators changed at the leading edge of a range shift, allowing them to understand how and why trees succeed during a range shift.

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#PruittData and the Ethics of Data in Science

Leadership can play an important role of a population dynamics, but is it the strength of the leaders or the willingness of the followers that has more influence?

Image credit: Bernard Dupont, CC BY-SA 2.0, Image Cropped

If you follow anyone in the fields of ecology or biology, chances are you’ve seen or heard of #PruittData, #PruittGate, #SpiderGate, or some other similar hashtag. We at Ecology for the Masses decided that we wanted to add our voice to the discussion, not to disparage anyone, but to take the opportunity to discuss ethics in science and data reporting.

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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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Brains Over Brawn

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

The Crux

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.

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It’s a Matter of Scale

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

The Crux

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.

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