Aphids can be a gardener’s nightmare. But they may be an evolutionary biologist’s dream. Because they’re pioneers in the history of life on Earth. For one thing, they’re now the only known animals to produce the chemical pigments called carotenoids, which help in cell repair and immunity. It’s the same stuff that makes tomatoes red.
More impressive, aphids got their ability to make carotenoids through a major shortcut. Millions of years back, they apparently grabbed the genes for making carotenoids directly from a carotenoid-producing fungus. And then incorporated those genes into the aphid genome. That’s according to a study in the April 30th issue of the journal Science. [Nancy Moran and Tyler Jarvik, http://bit.ly/928R4t]
Such a pickup is technically called horizontal or lateral gene transfer. And it’s not unique—among closely related organisms. But the fungi-to-aphid transfer took place between representatives of two completely different taxonomic kingdoms. The researchers conjecture that aphids might have pilfered the genes from a fungus that was infecting them. That’s really taking lemons and making lemonade. Which in this case would definitely be pink.
[The above text is an exact transcript of this podcast.]