Bbc Inside Science

More than 5,000 years of heavy agricultural labour by women can be read from the bones found in ancient cemeteries from the Neolithic to Iron Age times. Cambridge University anthropologist Alison Macintosh compared the arm bone dimensions and strength of women from these times with those of modern female athletes such as runners to rowers. Her conclusion is that average upper body strength of women through the Neolithic to the Iron age times exceeded that of today's semi-elite female rowers.A laboratory at the Scripps Research Institute have created a semi-synthetic bacterium with two new man-made genetic letters in its DNA, in addition to the natural four A, G, T and C. What's more, the engineered microbe can use its enhanced genetic alphabet to build synthetic amino acids into the proteins it makes. Chemist Floyd Romesberg talks to Adam Rutherford about what we can learn from his team's extraordinary feat of synthetic biotechnology, what we might gain from it and why, in his opinion, we've no need to be wor