IFL SCIENCE - We typically think of evolution as progressing in one direction, with a species getting “better” and “better” as it goes. But evolution is far more complex than that, as has recently been illustrated by an unusual organism: Galápagos tomatoes. These wild-growing fruits are shedding millions of years of evolution in order to reproduce long-lost chemical defences.
The tomatoes are descended from South American ancestors that were probably brought to the Galápagos by birds, and they have now started to produce a toxic molecular cocktail that hasn’t been seen in millions of years. The compounds in question are alkaloids, which are produced by nightshades like potatoes, eggplants, peppers, and tomatoes. They are bitter-tasting molecules that serve as a built-in pesticide to deter insects, fungi, and grazing animals from noshing on the plants or tubers
Generally speaking, animals on the Galápagos have few predators to worry about, but the same is not true for plants. As such, the production of these alkaloids can help protect vulnerable species. In low concentrations, these alkaloids are not harmful to humans, but higher concentrations can be toxic. This is why researchers from the University of California, Riverside (UC Riverside), started to examine the Galápagos tomatoes. They wanted to understand how the plants are producing these alkaloids.
In this instance, it isn’t that the tomatoes are producing the compounds, it's that they are making the “wrong” ones, as in they are creating chemicals that have not been seen in tomatoes since their early evolution.
“It’s not something we usually expect,” Adam Jozwiak, a molecular biochemist at UC Riverside explained in a statement. “But here it is, happening in real time, on a volcanic island.”