The discovery of fire was a major milestone in human evolution, giving our ancestors a way to stay warm, ward off predators, and eventually start cooking food. But exactly when this first happened is still intensely debated, as unambiguous evidence is difficult to find.

Incorporating more plant-based proteins could help people save on their grocery bill, but new research has found that it's not so simple when it comes to choices at the supermarket. Simon Fraser University researchers peeked into more than 87,000 grocery carts in Canada and Finland to study how much price influenced the type of protein people bought: animal-based or plant-based. Researchers discovered that while the price had to be right, having a variety of options also played a role.

Having Black teachers and other educators of color improves students' classroom experiences, research shows. They often serve as role models, set high academic expectations and teach material that connects to students' lives outside of schools.

Americans rarely marry outside of their race or class in a nation where residential segregation is relatively common. It is a dynamic widely viewed as a contributing factor to income inequality and intergenerational social mobility.