It is not uncommon for children to despise kale, broccoli or the bitter taste of Brussels sprouts. By the time we become adults, many of us have learned to eat our greens. But it was not just willpower. Proteins in our saliva may adapt and bind to bitter compounds, making them more palatable.

A study found that when people were repeatedly exposed to bitter compounds in cocoa, their saliva changed to produce proteins that rendered the flavor of those compounds less bitter.

“Bitter taste tends to be rejected,” said Cordelia A. Running, an assistant professor in food and nutrition science at Purdue University in Indiana. But, “this is something you might actually be able to change about yourself biologically.”

Grisly tactics for millions of years

Parasitoid wasps are the horror-flick killers of the insect world, devouring their hosts and eventually killing them, sometimes by bursting through their abdomens like in the movie “Alien.” Now, scientists have found concrete evidence, published in Nature Communications, that these insects have honed their grisly tactics over the course of millions of years. Using synchrotron X-ray imaging, researchers from Germany found parasitic wasps lurking inside more than 50 fossils of developing flies that were 30 million to 40 million years old.

“It’s the first time we definitely have proof of a developing parasitoid wasp inside its host in the fossil record,” said Thomas van de Kamp, an entomologist from the Karlsruhe Institute of Technology in Germany and lead author.

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