Tag Archives: population

The Why and How of Genetic Diversity

Whilst cichlid fish might look incredibly diverse, they are actually all relatively genetically similar. So how do we define genetic diversity, and how do we conserve it? (Image Credit: Emir Kaan Okutan, Pexels Licence, Image Cropped)

Biodiversity has become an immensely popular buzzword over the last few decades. Yet the concept of genetic diversity has been less present in everyday ecological conversations. So today I want to go through why genetic diversity is important, how we define it, and why there is often controversy about its application in conservation science. Read more

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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Jane Reid: Playing the Ecological Long Game

The red-billed chough, subject on one of Jane's long term studies of effects of the environmental on the size and structure of populations

The red-billed chough, subject on one of Jane’s long term studies of effects of the environmental on the size and structure of populations (Image Credit: Jean-Jacques Boujot, CC BY-SA 2.0, Image Cropped)

Our world is changing rapidly. Yet our perception of just how much it has changed is often dulled by our inability to compare what we see around us to what was around fifty years ago with enough clarity. This is one of the reasons that long-term scientific studies are so important. They give us a tangible assessment of just how much our world has changed, whether that be in the climate, how species have evolved, our how populations fluctuate.

Jane Reid is the new International Chair Professor at the Department of Biology at the Norwegian University of Science and Technology. Jane has spent years working with several long-term studies, some of them successful, others not so much. Sam Perrin and I spoke to Jane about the importance of long term studies in ecological science.

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Why Warmer Winters Don’t Always Help Geese

Image Credit: MaxPixel, CC0 1.0, Image Cropped

Contrasting consequences of climate change for migratory geese: Predation, density dependence and carryover effects offset benefits of high-arctic warming (2019) Layton-Matthews et al., Global Change BiologyDOI: 10.1111/gcb.14773

The Crux

Most of us know that climate change will bring warmer, shorter winters to most parts of the world. For many species in areas like the Arctic, it would be easy to interpret this as a good thing – plants grow earlier, so animals get more food, right? Naturally it’s never that simple. Many herbivorous species have evolved in sync with climate cycles so that their reproduction peaks when food becomes available. If season start dates change, these species may not be able to change their own cycles in time. Additionally, what happens if populations of their predators suddenly boom?

Today’s authors wanted to know what role a warming climate played in the population fluctuations of migratory barnacle geese (Branta leucopsis).

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Pinning it on the Polar Bear

Image Credit: Christopher Michel, CC BY 2.0, Image Cropped, Brightened

It’s an image that is ubiquitous in the media when the words ‘climate change’ pop up. The lone polar bear, drifting through the sea on a single ice floe. It is an effective image, evoking emotions like pity, loneliness and general despair for the plight of what has become the flagship species of what seems like the entire Arctic. But is associating the health of an entire ecosystem with one species useful, or dangerous?

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Parrots in Norway

Image Credit: Sandeeep Handa, Pixabay licence, Image Cropped

The Norwegian landscape is a beautiful thing. Spruce and pine groves piled on the side of mountains and fjords, moose and deer popping up in backyards, woodbirds flitting about on pristine hiking trails. Parrots screeching bloody murder into your ears as you re-enter the city.

No you did not read that wrong. It’s not happening yet, it in a couple of decades parrots, a type of bird not really associated with the sub-Arctic, could be a regular presence around Norwegian cities. So how could this happen, and why is it really quite concerning?

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