4–6
percent
Denisovan-derived
DNA in some
Melanesians
4
percent
Neandertal-derived DNA in
some europeans
Humans benefited by interbreeding
important immune system DNA came from Neandertals
NEWS BRIEFS
By Rachel Ehrenberg
Sole evidence
Most criminals know to avoid
leaving fingerprints at a crime
scene, but soon footprints may
also be a dead give-away. rather
than signature ridges, the sole
of the foot has an identifiable
pressure signature that can be
used to identify someone with
99 percent accuracy, an analysis
of 104 individuals reveals. The
new work examined only barefoot
walkers; how shoes and different
gaits might alter patterns isn’t
clear. But the data are now easy
to analyze, an international team
reports online September 7 in the
Journal of the Royal Society Interface, and foot-pressure devices
are easy to install, so there may
a future role for the identification
technique in the security realm.
— Rachel Ehrenberg
Breast-feeding gives women
an edge
Mothers’ milk has a mean streak.
Breast-feeding mothers act far
more antagonistically toward a
competitor in a lab task than
bottle-feeding mothers or women
who have never given birth do, say
UCLA psychologist Jennifer Hahn-
Holbrook and her colleagues. Like
mama bears and other lactating
mammals, breast-feeding moms
are biologically primed to protect
themselves and their babies, the
researchers propose online August
26 in Psychological Science. in the
lab test, lactating women delivered
what they thought were especially
long and loud sound blasts to
vanquished opponents in another
room, yet exhibited lower blood
pressure while doing so than other
women did. — Bruce Bower
www.sciencenews.org
October 8, 2011 | SCIENCE NEWS | 13
