Low potential for evolutionary rescue from climate change in a tropical fish (2020) Morgan et al., PNAS, https://doi.org/10.1073/pnas.2011419117
As the planet warms thanks to climate change, the massive bodies of water that are our oceans grow hotter. Since they’re larger, and much poorer conductors of heat, they don’t tend to vary in temperature as much as the land does, which means many species will have to get used to longer, warmer periods.
If species can adapt to hotter temperatures through thermal acclimation, ecosystems may not be too harshly affected. However if they’re unable to adapt, marine ecosystems may undergo rapid changes as they lose native species. Today’s researchers looked at a key study species – the zebrafish – in order to figure out how well fish can respond to increasing temperatures.
Growth is a critical aspect of life for all organisms, and understanding what can and cannot affect it allows us to predict what effect climate change may have on organisms like these zebrafish (Image Credit: Lynn Ketchum, CC BY-SA 2.0).
Warming increases the cost of growth in a model vertebrate (2019) Barneche et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13348
In ecology, how organisms grow is relevant across all levels of life. Growing faster than others can be selected for as an evolutionary advantage, if being bigger earlier means that you have a competitive advantage over other members of your species.
Because growth is so critical to life, it is important to understand what may affect the ability of an organism to grow. The only way an organism can grow is by converting energy it acquires from food to its own body mass, but outside influences, like temperature, can affect how efficient an organism is at this energy conversion. The authors of today’s paper wanted to investigate if this efficiency and the cost of growth itself changed across a range of projected temperatures.