When Environments Change

Can Algae save the world?

In today’s world with an increasing human footprint across the natural world, scientists believe we may be entering a sixth mass extinction. Fragmented habitats, introduction of invasive species, and climate change are just some of the factors leading to this mass extinction.  A lot of species still have yet to be recorded, so the number of extinctions of populations and species documented by scientists are likely to be large underestimates (Barnosky et al. 2011).  Climate change is one factor among many that is leading to the loss of biodiversity. Therefore, it is important for scientists to understand how populations respond to rapid environmental change. It is known that evolutionary history may affect risk of extinction within populations due to the accumulation of mutations, or pleiotropy. In one environment certain mutations will be favored, but in others they may have detrimental effects that reduce fitness, or reproductive success of a certain genotype in a population. (genotype being the genetic makeup of an individual) This would lower a population’s ability to withstand environmental change due to the accumulation of mutations which aren’t suited for the new environment. (MacLean et al. 2004) Understanding evolutionary history is crucial for understanding how populations will respond to environmental change caused by climate change. In the October edition of the Journal of Evolutionary Biology there was a study looking at how evolutionary history affects extinction probability.  Its title is “The effect of selection history on extinction risk during severe environmental change”. This study looked at how the extinction risk of populations of the green algae Chlamydomonas reinhardtii changed with various stressful environments (Lachapelle et al. 2017).

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The Mystery of the Coral Triangle

The Enigma

Coral reefs are prime examples of thriving diversity, none more than the Coral Triangle, which is located in the ocean surrounding the archipelagos of the Philippines and other islands above Australia, pictured in the orange area of Figure 1. For hundreds of years, the Coral Triangle has fascinated scientists. This area contains more species of corals than any other area in the world, but scientists do not know how so many corals came to occupy the Coral Triangle. Recently, a group of scientists led by Danwei Huang came together to investigate four hypotheses on diversity in hopes to find which one is most accurate with regard to the corals of the region.

A map of the area north of Australia where the Coral Triangle is located, along with ecologically relevant and similar areas.
Figure 1. A map depicting the Coral Triangle in orange  and ecologically similar regions surrounding it in blue (Figure 1 of Huang et al. 2018).

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