New Scientist 14Feb2020

8 February 2020 | New Scientist | 19

Ancient humans

Diet Astronomy

Microbiome change

counters bee virus

Honeybee gut bacteria

have been genetically

modified to protect the

insects against a lethal

infection that can cause

colonies to collapse.

Researchers at the

University of Texas,

Austin, engineered a bee

gut bacterium to generate

RNA that disables the

deformed wing virus

(Science, doi.org/dkvq).

Cyborg jellyfish

swim a lot faster

Electronics embedded in

live jellyfish allow them

to be remote-controlled

by stimulating muscle

contractions so they swim

at three times their normal

pace. The hope is to use

the animals to monitor

oceans by adding sensors

to check oxygen content

and temperature (Science

Advances, doi.org/dkvt).

Fatal accidents rise

after clock change

The risk of fatal car crashes

goes up about 6 per cent

in the week after summer

time starts before returning

to normal. Researchers say

about 29 deadly accidents

in the US in the week after

the transition could be

avoided each year if clocks

weren’t changed (Current

Biology, doi.org/dkt5).

Lots of us are a bit

more Neanderthal

PEOPLE of European and African

ancestry have more Neanderthal

DNA in their genomes than

previously thought. This is the

finding of a study that identifies,

for the first time, the Neanderthal

genes present in modern day

people of African ancestry.

Neanderthals lived in Europe

and central Asia until their demise

some 40,000 years ago. Thanks to

genetic studies, we know that after

modern humans left Africa, they

A VEGETARIAN diet has been linked

with a lower risk of having a urinary

tract infection, at least for women.

The infections are usually caused

by bacteria from faeces entering the

urinary tract. Chicken and pork are a

major reservoir of E. coli, a bacteria

that commonly causes UTIs. So

Chin-Lon Lin at Tzu Chi University in

Taiwan and his colleagues looked at

whether vegetarians would have a

lower risk of UTIs than meat-eaters.

They looked at 9724 people in

Taiwan over 10 years and found

that vegetarians were 16 per cent

less likely to have a UTI than their

meat-eating counterparts. But

when the researchers analysed the

diets of men and women separately,

they found the protective effect was

present in women but not men

(Scientific Reports, doi.org/dkvm).

Lin says vegetarians may have a

lower risk of UTIs because they have

a lower risk of exposure to E. coli.

It is also possible that the high fibre

content in their diet helps them to

avoid constipation and reduces the

risk of E. coli growing in their gut.

However, there are caveats. For

example, the participants were all

Buddhists based in Taiwan. And

while the study tried to adjust for

some factors, it didn’t account for

pregnancy, which is a major risk

factor for UTIs. Adam Vaughan

interbred with Neanderthals,

leaving traces in each other’s DNA.

Previous research showed that

about 1.5 per cent of the DNA of

people of European ancestry came

from these events, while people of

east Asian ancestry had a bit more

than this. Because genomes of

people of African ancestry showed

little or no evidence of this genetic

exchange, Neanderthal genes

were identified in people of

European ancestry by comparing

their genomes with people of

African ancestry, assuming they

were a Neanderthal-free baseline.

To find out if this assumption

Two stars have a

strange jiggly orbit

A PAIR of distant stars are locked

in a weird, wobbly dance, probably

the result of an effect predicted

by the theory of general relativity.

One of the stars, PSR J1141-6545,

is a pulsar, a dense neutron star

that emits beams of light. It orbits

a white dwarf, which formed when

a lower-mass star ran out of fuel

and lost its outer layers.

Using years of observations,

Vivek Venkatraman Krishnan at

the Max Planck Institute for Radio

Astronomy in Germany and his

team calculated the stars’ orbits

around one another with extreme

precision and found it was wobbly.

This oddity is due to an effect

called frame dragging, which is

predicted in the theory of general

relativity and occurs when a fast-

spinning object drags space-time

around it. The researchers worked

out that the white dwarf is

spinning faster than the pulsar,

which is twirling fairly slowly at

about 2.5 rotations per second.

That indicates the system seems

to have formed in an unexpected

order. Usually, the pulsar forms

first, and then as the white dwarf

is losing its outer layers, the pulsar

sucks up that material and starts

to spin faster. In this case the

white dwarf formed first (Science,

doi.org/dkvx). LC

was correct, Joshua Akey at

Princeton University and his team

devised a new method of detecting

archaic ancestry in DNA. Looking

at genomes of people of African

ancestry in Africa and elsewhere

in the world today, this revealed

an unexpectedly high Neanderthal

signature of 0.3 per cent in people

of African ancestry, compared

with less than 0.02 per cent in

earlier studies (Cell, doi.org/dkvs).

By extension, that result means

the Neanderthal component

of the genomes of modern-day

people of European ancestry was

underestimated. Alison George

Vegetarians may have a

lower risk of getting UTIs

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Really brief

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