The extinction of large animals led to the human brain growing, a new study reveals. When humans first emerged in Africa 2.6 million years ago the average animal size was more than 1,000 pounds, making them easy prey. Throughout the Pleistocene era, creatures' sizes decreased by 90 percent, which forced our ancient ancestors to developing cunning and bold methods to capture their next meal. As they shifted to hunting small, swift prey animals, humans developed higher cognitive abilities and experienced a growth of brain volume from 650cc to 1,500cc. When humans first emerged in Africa 2.6 million years ago the average animal size was more than 1,000 pounds, making them easy prey Previous research shows that early humans survived by hunting large game, which provided them with the necessary fat and sources of energy to survive.

Every drop of seawater contains thousands of cells that can reveal the diversity of life in our ocean. Using a self-contained robotic laboratory and an autonomous underwater vehicle, MBARI scientists and engineers are developing advanced collection techniques that may one day simplify the jobs of biologists and resource managers. A recent study confirms that autonomously collected samples of environmental DNA (eDNA) are equivalent to samples collected by people using traditional, manual methods. A growing body of research indicates that wildlife surveys using eDNA analyses can be as (or more) accurate than simply using traditional methods. As such, eDNA assessments appear to offer a very promising and cost-effective means for monitoring biodiversity, which presents an attractive proposition for researchers as well as resource managers who study ocean ecosystems.

Scientists have reversed diabetes in mice by giving them an organ grown in a different species - rats. This is the first time an inter-species organ transplant has successfully treated a medical condition. The breakthrough is seen as proof of principle that'spare-part surgery' could one day be used to overcome disease in humans. Scientists have reversed diabetes in mice (stock image pictured) by giving them an organ grown in a different species - rats. Hiromitsu Nakauchi, a genetics professor at Stanford injected rat embryos with mouse stem cells.