#SizeMatters

Organisms are shrinking in response to global warming, with phytoplankton species exhibiting some of the greatest declines in body size. Our planet largely depends on phytoplankton, as these drifting microscopic algae sustain all aquatic food webs and are responsible for half of the world’s oxygen production and carbon fixation.

What happens when a species evolves to a different size? I have been addressing this question using a technique called ‘artificial selection’: I evolved a green microalga species (Dunaliella tertiolecta) toward smaller and larger sizes and evaluated physiological and ecological consequences of the size shift.