New Scientist - 14.09.2019

14 September 2019 | New Scientist | 17

Linguistics

Primatology Palaeontology

Timing goes awry

on coral reefs

Climate change seems

to be prompting corals

to spawn days or even

months out of sync with

each other. Releasing

their tiny eggs and sperm

bundles at different times

may be one reason why

coral reproduction has

been declining (Science,

doi.org/c983).

Vegetarians have

healthier hearts

Eating a vegetarian diet

has been linked with a

22 per cent lower risk

of heart disease, but a

20 per cent increased risk

of stroke. Over a 10-year

period, vegetarians had

10 fewer cases of heart

disease per 1000 people

than meat eaters, but

three more cases of stroke

(The BMJ, doi.org/c984).

Explosions made

the lakes of Titan

Saturn’s largest moon

Titan is dotted with lakes

brimming with liquid

methane. We assumed

these formed by rocks

dissolving, but it turns

out the irregular shapes of

the lake basins are better

explained if they were

formed by explosions

(Nature Geosciences,

DOI: 10.1038/s41561-

019-0429-0).

All languages get info

over at the same rate

SPEECH conveys information at

the same optimal rate, no matter

what language we use.

François Pellegrino and his

team at the University of Lyon

in France analysed 17 languages,

from English to Japanese, that

vary greatly in terms of the

number of basic sounds, number

of syllables, use of tones and so

on. For instance, there are 7000

distinct syllables in English and

just a few hundred in Japanese.

AN ARTIFICIAL intelligence that

detects, tracks and recognises

chimpanzees could help us fathom

their complex behaviour in the wild.

Arsha Nagrani at the University

of Oxford and her colleagues have

developed a facial recognition AI

that can detect and identify chimps

in video recorded in the wild. Using

it reduces the time and resources

needed to track animals.

The team trained the AI on

50 hours of footage of 23 chimps in

Bossou in Guinea, West Africa. This

yielded 10 million facial images. The

AI learned to continuously track and

recognise animals, says Nagrani.

It worked even on low-quality

images and when the chimps

weren’t looking at the camera.

Overall identity recognition

accuracy was 92 per cent.

When faced with 100 random

still images, the AI had an accuracy

of 84 per cent, taking 30 seconds

to complete the task. Researchers

experienced in recognising the

chimps took 55 minutes and had

an average accuracy of 42 per cent

(Science Advances, doi.org/c958).

The system will allow researchers

to more efficiently examine how

behaviour and social interactions

vary over years and generations

to track changes in community

structure over time. Donna Lu

The team worked out the

information density of each

language, in terms of bits of

information per syllable. This

varies from 5 bits per syllable for

Basque to 8 bits for Vietnamese.

Next, the team asked 10 native

speakers of each language to read

15 equivalent texts. What they

found was that while the speech

rate – in terms of syllables per

second – varied, those speaking

more information-dense tongues

speak more slowly, on average.

For instance, Basque was spoken

at a faster rate of 8 syllables per

second, on average, while

Ancient worm had a

bit of get up and go

AN EXTINCT creature that looked

like a cross between a millipede

and an earthworm was one of

the first animals that could move

under its own power.

Yilingia spiciformis was up to

27 centimetres long and 2.6 cm

wide. It had body segments, each

with two spiky appendages, so

looked a bit like an ear of wheat.

The fossilised remains, found in

China, are up to 551 million years

old. This puts it in the Ediacaran

period, when the first confirmed

multicellular animals appear in

the fossil record.

As well as fossils of Y. spiciformis,

the rocks also yielded 13 trace

fossils: tracks that were left by

the animals as they moved along

seabed sediment. One body fossil

was actually found right next to

its tracks, offering hard evidence

that Y. spiciformis was able to

move (Nature, doi.org/c959).

“It is the first segmented animal

that has been shown to be capable

of directional movement,” says

Shuhai Xiao at Virginia Tech.

Xiao says that Y. spiciformis isn’t

quite the oldest animal that could

move from A to B. “The first

mobile animal is probably about

565 million years old,” he says.

One such creature was the slug-

like Kimberella. Michael Marshall

Vietnamese was spoken at

5 syllables per second, making

the rate at which information is

conveyed similar for both (Science

Advances, doi.org/gf7jw3).

“There’s this pretty strong push

to go for an optimal information

rate,” says team member Dan

Dediu. “We all have similar brains

and similar articulatory organs, so

there are universal constraints.”

What is behind the constraints

isn’t clear. It might be to do with

the effort of speaking or of

understanding speech, or be

related to brainwave frequency,

says Dediu. Michael Le Page

AI that tracks chimps will

help reveal their wild lives

TOM SHLESINGER

KYOTO UNIVERSITY, PRIMATE RESEARCH INSTITUTE

Really brief

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