Primitive air-breathing fish, whose direct ancestors first appeared around 400 million years ago, show mechanisms controlling the heart which were previously considered to be found only in mammals, according to Science Daily.

Mammals show an increase in heart rate when breathing in and a decrease during expiration -- a cardiorespiratory process known as respiratory sinus arrhythmia (RSA). This process and its underlying control mechanisms have been considered by many scientists to be solely mammalian but the present study questions this assumption.

Take a good look at this photo: It shows you 1.6 billion years old fossilized oxygen bubbles, created by tiny microbes in what was once a shallow sea somewhere on young Earth, according to Science Daily.

The bubbles were photographed and analyzed by researchers studying early life on Earth.

Microbes are of special interest: They were not only the first life forms on Earth. They also turned our planet into a tolerable environment for plants and animals and thus their activity paved the way for life as we know it today.

Some of these early microbes were cyanobacteria that thrived in early shallow waters. They produced oxygen by photosynthesis, and sometimes the oxygen got trapped as bubbles within sticky microbial mats.

Researchers say mind-altering compound may have evolved to trip up fungus-eating insects

They’ve gained notoriety for their hallucinogenic side-effects – but, so-called magic mushrooms may have developed their mind-altering properties as a way to protect themselves, according to Daily Mail.

Scientists have long remained perplexed by the ‘biological mystery’ of psychedelic mushrooms, which contain the compound psilocybin but appear to have little in common between the different species.

Nocturnal animals can use the stars and the Milky Way to find their way during the darkest hours. While animal navigation is studied all over the world, some of the leading researchers.  In a recent article they sum up the research so far and give their thoughts on challenges to come, according to Science Daily.

There are advantages to being active in the night. Fewer parasites are active and the same goes for predators. What is more, there are not as many competitors for food as there are during the day. For animals that migrate or search for food over vast distances in particular, the cooler hours of the night are preferable to the heat of the sun.

Is evolution predictable? Are changes in a species random or do they happen because of natural selection? According to Science Daily.

"Evolution often appears random, even when driven by the deterministic process of natural selection, because we just aren't aware of all the environmental fluctuations and other factors taking place that drive change," says biologist Zach Gompert. "If we had a better understanding of the mechanisms at play, we might have a better picture of evolutionary change and its predictability."

Gompert and colleagues used data from the past to test their ideas of evolutionary predictability.