Dr Michael Detmar, from the Massachussetts General Hospital Cutaneous Biology Research Center, said that measuring the number of these vessels in human tumours could help doctors predict the likelihood of spread outside the breast.

BBC: tumour in breast

Madu, from King Edward's School (for boys) had taken chemistry, maths, physics and general studies, and his brother biology, chemistry, maths and general studies.

BBC: NEWS | UK | Education | Grandmother, 78, passes A-level

Biology provides some of the general primate psychology that we have, like pro-social tendencies, sense of fairness, following rules.

CNN: He studies where morals come from

But the authors of the paper in Current Biology said females, particularly adolescent females, and young chimps in general were seen exhibiting this behaviour more frequently than adult males.

BBC: Chimps sharpened the spears with their teeth