Tag Archives: modelling

Getting Older is Favored in Choosy Species

One of the timeless (get it?) questions in biology is why did we evolve to age? What benefit is there to getting older and deteriorating before we die? (Image Credit: medienluemmel )

Evolution favours aging in populations with assortative mating and in sexully dimorphic populations (2018) Lenart, P. et al., Scientific Reports, 8, https://doi.org/10.1038/s41598-018-34391-x

The Crux

We as humans are familiar with aging as the slow deterioration of our bodies and minds over time, and we can see this in other animals as well (think of the old family dog with white around its muzzle). The interesting thing is that not every species ages in the way that we do, that is to say that they stay forever “young” until they die. In a biological sense that means that while these organisms can and do die, their risk of death remains the same throughout the course of their lives. This would be akin to your grandparents, in their old age, having the same risk of death as you during the prime of your life. Or, conversely, you being just as likely to die in your sleep as a senior citizen.

The authors of this study note that, while theories for the evolution of aging abound in the scientific literature, they are not broadly applicable and some of them even require the existence of aging for the evolution of aging to even happen. They wanted to find out in what situations aging individuals could outcompete non-aging individuals, and vice-versa.

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Refining Nemo: Musings from the Australian Society of Fish Biology Conference

The Australian Society of Fish Biology's 2018 Conference delivered some of the most engaging, intriguing talks I've had the pleasure of witnessing

 As a fish ecologist living in Norway, it’s a joy to be able to travel to Melbourne and interact with the people that are driving forward fish science in my home country. So when I found out that the Australian Society of Fish Biology’s annual conference was taking place 3 days after my first flight home since 2016, I knew it was an opportunity I couldn’t pass up.

We’re on the last day of the conference at the moment, and over the next 2 months I’m looking forward to bringing you a number of insights, including interviews with guest speakers Eva Plaganyi and Gretta Pecl and pioneers of intriguing projects like Peter Unmack and Jarod Lyon. I’ll also have a fish edition of The Changing Face of Ecology, and some articles on how the angling community and the fish science community interact in a country with one of the most unique fish assemblages in the world.

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Species Associations in a Changing World

Species associations will change as the climate rises. So how can we attempt to predict these changes

Species associations will change as the climate rises. So how can we attempt to predict these changes (Image Credit: Charles J Sharp, CC BY-SA 4.0)

Using joint species distribution models for evaluating how species-to-species associations depend on the environmental context (2017) Tikhonov et al, Methods in Ecology and Evolution, DOI: https://doi.org/10.1111/2041-210X.12723

The Crux

Statistical modelling is a crucial part of ecology. Being able to provide an (admittedly simplified) mathematical description of the relationship between species abundance, range or density and the surrounding environment is a huge help in taking proactive steps to manage an ecosystem, or predicting species numbers in other areas.

Historically models have used environmental variables to explain population or evolutionary developments in species. When modelling a single species, many ecologists have taken into account that the presence of other species (for example competitors or predators) may influence the presence of this single species. This has led to the rise of joint species distribution models (JSDMs), which take into account environmental variables, as well as the interactions between certain species. These models have become increasingly useful, and with environmental change now being the norm in many ecosystems, this week’s authors produced one such model that accounts for changes in species interactions in the face of changing environmental factors.

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