Where did humanity as a species come from? By the end of the 19th century scientists had accepted Darwin’s theory of evolution. So what does this mean for humanity? Nowadays humans live (almost) all over the world, but where did the first humans live? Given that we all belong to one species scientists thought that we can’t have evolved independently everywhere, but that there was an original cradle of humanity and later humans embarked on their quest to populate (almost) all continents. The first evidence for early humans was found in south-east Asia. Bias and false ideas of how early humans should have looked like led to a long period of time in which people believed humanity stems out of Asia. But in the end scientists found evidence of earlier humans in Africa. Dig into the history of humanity by listening to this week’s episode of Good in Theory.

How come predators never hunt their prey to extinction? Is this balance of species in an ecosystem a natural law or more of a superstition? Already the ancient Greeks seemed to have believed in a balance of nature and nowadays this terminology is still sometimes used. But what exactly is this balance and can it be defined in a scientific way? This question was raised in the 18th century when the discovery of fossils of unknown species radically changed our view on ecology. While some scientists still tried to make sense of it, today the world “balance” is no longer seen as useful when describing ecosystems. For a good balance of entertainment and information listen to this week’s episode of Good in Theory.

Why does your tea get cold if you leave it standing around for too long? Because the temperature of the tea adjusts to the temperature of the room, but why? The process of transferring heat puzzled many scientists. In the late 18th century caloric theory emerged in which the temperature of a body depends on the amount of “caloric” it possesses. Caloric was thought to be a weightless fluid which flows from hotter to colder bodies. The theory succeeded in explaining phenomena like your tea going cold. Although the theory managed to capture some key properties of heat it had several shortcomings and ultimately didn’t stand the test of time. If you are burning to learn more, listen to this week’s episode of Good in Theory.