Humans

By Clare Wilson

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There are many ways that our great ape relatives can remind us of ourselves: through their anatomy, cleverness and social relationships, for instance. But never has the resemblance been so striking for me as today, when I watch gorillas carrying out a very human past-time: solving puzzles.
The gorillas in question live at Port Lympne Reserve in Kent in the UK. The task involves moving a hazelnut treat down a vertical maze using sticks or the inbuilt cogs, until it is released at the bottom. It is very similar to a game I loved as a child, called Downfall, … More

By Krista Charles

A very small part of our genome might be unique to modern humansCueImages/Alamy
Modern humans have been around for about 350,000 years. In that time, we have continued to evolve and our DNA has changed – but, only a small per centage of our genome may be unique to us.
Nathan Schaefer at the University of California, San Francisco, and his colleagues created a tool called the Speedy Ancestral Recombination Graph Estimator (SARGE), which allowed them to estimate the ancestry of individuals.
More specifically, it helped identify which bits of the modern human genome aren’t shared with other hominins – meaning they weren’t present in the ancient ancestors we shared with Neanderthals and Denisovans, and also haven’t been introduced to the human gene pool through interbreeding with these ancient humans.Advertisement
“Instead of building a tree across the genome that shows how a bunch of genomes are related on average genome-wide, we wanted to know what the ancestry of individuals looks like at specific sites in the genome,” says Schaefer. “We basically wanted to be able to show how everyone is related at every single variable position in the genome.”
The team analysed one Denisovan, two Neanderthal, and 279 modern human genomes to distinguish what parts of the genome separate modern humans from archaic hominins. They found that only 1.5 to 7 per cent of the modern human genome is unique to us.

The figure may seem low but that is partly because we inherited plenty of DNA from the ancient ancestral species that ultimately gave rise to modern humans and the Neanderthals and Denisovans.
What’s more, modern humans then interbred with Neanderthals and Denisovans, picking up even more DNA that isn’t unique to our lineage.
“It’s true that individual humans have a very low per cent of their genome that might have been from Neanderthal or Denisovan ancestry – non-Africans can have between 1.5 to 2.1 per cent of their genome that originated from Neanderthal ancestry,” says Schaefer.
But we know that the exact form taken by that small amount of Neanderthal DNA varies from individual to individual – meaning two people can both have 2 per cent Neanderthal DNA but share little Neanderthal DNA in common. These differences add up, says Shaefer. Some estimates suggest about 40 per cent of the Neanderthal genome can be pieced together by combining genetic information from a wide variety of living people.
The mutations that contribute to uniquely human features are contained within a small part of the genome and seem to mainly affect genes related to brain development.
“Knowing how those variants affect human mental capacities would help us understand the cognitive differences between humans and Neanderthals,” says Montgomery Slatkin at the University of California, Berkeley.
Journal reference: Science Advances, DOI: 10.1126/sciadv.abc0776
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To become an interplanetary species, we may have to genetically engineer ourselves to be more resilient, says geneticist Chris Mason. He has a 500-year plan for life away from Earth

Earth

14 July 2021

By Joshua Howgego

Rocio Montoya
CHRIS MASON likes to think about the future. He isn’t dreaming about a summer holiday, or even planning his retirement. His thoughts extend much further – to the point where Earth is no longer a suitable home for humans.
Alarmed at the prospect, Mason has sketched out a plan of action in the form of his book The Next 500 Years: Engineering life to reach new worlds. It covers some of the usual ground: how we will first establish bases on the moon and Mars, and later on the solar system’s outer moons. Eventually, we will make an epic trip … More

By Layal Liverpool

Race-based adjustments are widely used in some diagnostic testsSean Justice/Getty Images
THE assumption that Black people have a lower level of cognitive function than white people was, until recently, built into a formula used by the US National Football League to settle head injury lawsuits. The NFL has now pledged to stop using this “race-norming” formula, but race-based adjustments in routine diagnostic tests remain pervasive in mainstream medicine. Although some scientific organisations are working to remove such adjustments, many contacted by New Scientist declined to take a stance on the issue, which … More

Many people strive to touch their toes or do the splits, but it is perfectly possible to get all the benefits of stretching without pushing your body to its limits

Health

14 July 2021

By Caroline Williams

Harriet Noble/Studio Pi
“I BEND so I don’t break.” No one knows who first coined this phrase, but search for it online and you will find it accompanying numerous pictures of yogis in various states of contortion. Flexibility, according to common wisdom, is not only impressive to look at, but something we should actively work towards.
Scientifically, however, the question of whether we should stretch to become more flexible has been difficult to answer. Assumptions about the benefits of stretching to prevent sports injuries and greater flexibility being better for our overall physical fitness hadn’t been confirmed by studies. Does it matter if you can’t touch your toes, let alone do the splits? Even in sports science, where most of the research has been conducted, there has been little agreement.
In recent years, though, answers have started to emerge. The surprising outcome is that, while stretching may well be good for us, it is for reasons that have nothing to do with being able to get your leg behind your head.
One thing is for sure: stretching feels good, particularly after a long spell of being still. We aren’t the only species to have worked this out. As anyone with a dog or cat will know, many animals take a deep stretch after lying around. This kind of stretching, called pandiculation, is so common in nature that some have suggested it evolved as a reflex to wake up the muscles after a spell of stillness.
Pandiculation aside, other species don’t seem to spend any time maintaining and extending their range of motion. Which raises the question, is there any reason why we should? … More

By Jason Arunn Murugesu

Neuroscience studies mostly don’t look at sex differencesAndrew Brookes/Westend61 GmbH/Al
Top neuroscience research papers are eight times more likely to only study male participants or samples compared with female-only studies, a review has found. In addition, only 4 per cent of papers look for sex differences in their data, suggesting that neurological disorders in women may be being overlooked.
Liisa Galea at the University of British Columbia, Canada, and her colleagues analysed the sex of samples used in every new research paper published by three of the world’s most respected neuroscience journals … More

By James Urquhart

A Stone Age pot from Europe that may have been worn around the neck or waistBine Kramberger
Some late Stone Age Europeans may have carried make-up inside miniature bottles that they wore around their necks or waists more than 6000 years ago.
Researchers have discovered traces of ingredients known to be used in cosmetic formulations by later civilisations inside small bottles unearthed in Slovenia, dating to between 4350 and 4100 BC.
The finding suggests that lead-based cosmetics were possibly used in Europe more than 2000 years earlier than previously thought, and more … More

By Clare Wilson

Aaron, Jess and Josh must navigate the ethics of an unusual surrogacyMonument Releasing
The Surrogate
Jeremy Herch
UK cinemas
THE Surrogate is billed as being about a moral dilemma, so I assumed that the film would address some of the complex ethical questions surrounding surrogate pregnancies, when someone deliberately conceives in order to give the baby away.
For example, if the surrogate is paid a fee, some feel that the arrangement can seem exploitative, and even when people do it for altruistic reasons, problems can arise if participants change their minds halfway. … More