Tag Archives: latitude

Some (Don’t) Like it Hot

Do latitudinal and bioclimatic gradients drive parasitism in Odonata? (2021) da Silva et al., International Journal for Parasitology. https://doi.org/10.1016/j.ijpara.2020.11.008

Image Credit: Adam Hasik, image cropped

The Crux

If there is one thing that people know about me and my research it’s that I love parasites. They’re everywhere, and more than half of all animals are parasites. They also make ecosystems more stable and link organisms within food webs to one another. For example, some parasites connect prey animals and their predators by making it easier for the predator to find and/or eat the prey. Though they can be found all over the world, there are a variety of environmental factors that make it more likely for a parasite to be found in a given environment. Today’s study focuses on one particular hypothesis related to the effects of the environment, the latitudinal diversity gradient (LDG, see Did You Know).

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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

Ecology of the GoT Dragons

Image Credit: Game of Thrones, 2019

Adam and Sam talk macroecology and that’s pretty much it. How small would these dragons be? It’s very anti-climactic. We’ll do a supplemental later. Also SPOILERS. Though as we were a week behind, there’s some stuff that is currently incorrect re: the current status of the GoT dragons. Spoilers.

04:02 – Everyone’s Favourite Dragons
13:15 – The Ecology of the Dragons
40:13 – Balerion the Big Boi vs. The US Military

And as usual, you can check out last week’s podcast on the physiology of these flappy flaps flaps below.

Bigger is Not Better

Not all GPS coordinate data are created equal, and some of it may actually be meaningless. (Image Credit: Daniel Johansson, Pexels licence, Image Cropped)

The smartphone fallacy – when spatial data are reported at spatial scales finer than the organisms themselves (2018) Meiri, S., Frontiers of Biogeography, DOI: https://escholarship.org/uc/item/2n3349jg

The Crux

One of the greatest annoyances when using museum specimens, old datasets, or large occurrence databases (such as GBIF) is when the locality of an occurrence is only vaguely described, and the coordinate uncertainty is high; “Norway” or “Indochina” doesn’t really tell you much about where that specific animal or plant was seen. Luckily, the days where such vague descriptions were the best you could get are long gone, as most of us now walk around with a GPS in our pockets, and even community science data can be reported very accurately, and more or less in real-time.

However, we have now encountered the opposite problem: the reported coordinates of organisms are often too precise to be realistic, and in the worst-case scenario, they might be borderline meaningless. The author of this study wanted to highlight how this advance in technology coupled with our eagerness to get more accurate data and results have made us too bold in our positional claims.

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