On the radar

The pick of the science news

It's all in the wrist

When our ancestors started walking on two feet, did they lift their knuckles off the ground, or did they swing down from trees? A new US study of wrist bones in chimps, bonobos and gorillas comes down on the side of trees.

“Contrary to previous expectations, features long assumed to indicate knuckle-walking behaviour are not found in all African apes, show different developmental patterns across species, and are found in non-knuckle-walking primates as well,” write the researchers in the Proceedings of the National Academy of Sciences USA this week.

Instead the wrist evidence suggests that human bipedalism evolved from a more arboreal ancestor, they conclude.

Cancer stingers

Scientists have developed a minuscule nanocarrier to deliver bee toxin to cancer cells. Melittin, a peptide in honeybee venom, “bursts” cells by affecting lipid membranes, so using it to kill cancers runs the risk of killing healthy cells too.

But researchers in Missouri found that by packaging “payloads” of melittin into nanoparticles they could target the poison at cancer cells in mice.

“In this study, we report what we believe is a new paradigm for targeted delivery of this and other problematic classes of cell-penetrating peptides to kill cancer cells both in vitro and in vivo,” states the report, published as a technical advance in the Journal of Clinical Investigation.

By numbers

59

The percentage reduction in the risk of developing pre-menopausal breast cancer seen in women who breastfeed where there’s a family history of early onset of the disease, according to a study in the Archives of Internal Medicine

60

The estimated speed, in kilometres per second, of particles entering earth’s atmosphere in the Perseid meteor shower (pictured )this week