Science news digest – 2nd July 2013
In the science news this week, the origins of throwing are revealed, mitochondrial transfer is backed by the Government, and finally… has Voyager 1 really left the Solar System?
Origins of human throwing are revealed
Early humans evolved the ability to throw about two million years ago, according to new research published in Nature.
Changes in the anatomy of the now-extinct species, Homo erectus, allowed this ability to develop. The anatomical changes coincided with the intensification of hunting during this period.
Throwing helped early hunters to evolve and migrate around the globe, reported the BBC.
The ability to throw objects at high speeds is unique to humans. The chimpanzee can only reach speeds of about 20mph whereas professional athletes can throw objects at 90mph.
The researchers studied the throwing movements of baseball players in order to understand the biomechanics of throwing for modern humans.
They found that the shoulder acts like a slingshot that stores elastic energy, which when released, generates the fastest motion the human body can produce.
Neil Roach, from George Washington University, who led the study, explained that the changes in the anatomy of hominins (early humans) occurred two million years ago.
"Success at hunting allowed our ancestors to become part-time carnivores, eating more calorie-rich meat and fat and dramatically improving the quality of their diet.
"This dietary change led to seismic shifts in our ancestors' biology, allowing them to grow larger bodies, larger brains, and to have more children, and it also did interesting things to our social structure.
"We start to see the origins of divisions of labour around that time, where some would be hunting, others would be gathering new foods.
"It probably also allowed us to move to new environments, such as areas that did not have vegetation to support us before we had the ability to hunt," he said.
He added that the hypothesis that the anatomical changes had a direct relationship with the changes to the hunting habits of early humans needed further study before it could be confirmed.
Another team member, Daniel Lieberman from Harvard University, said that the most interesting result for him was that half of the power humans generate from throwing comes from elastic energy stored in the shoulder.
"That's not a by-product of evolution for something else, it's clearly an adaptation. There were shifts in our anatomy that enabled us to throw accurately, so we want to understand better just what those early hunting challenges were,” he said.
Government backs mitochondrial transfer treatment
Plans that would allow for an IVF treatment which involves using the genetic material from three people are being pushed ahead by the Government, reported the Guardian.
The procedure, called mitochondrial transfer, would prevent some devastating disorders which are caused by genetic mutations in mitochondrial DNA.
Mitochondria, sometimes known as the powerhouses of the cells, are passed on in the egg from the mother, but for one in 6,500 people these mitochondria are faulty causing disorders that affect the heart, brain and muscles.
A consultation by the Human Fertilisation and Embryology Authority (HFEA) published in March suggested that the public was generally supportive of the procedure, and draft regulations are expected to be ready this autumn.
Dame Sally Davies, the chief medical officer for England, announced the push from the Government last week, saying that “it's only right that we look to introduce this life-saving treatment as soon as we can.”
If MPs approve the regulations, Britain would be the first country to allow the treatment to be used.
However, there are some groups who oppose the procedure, because one of the techniques involves destroying an IVF embryo. It would also be the first IVF treatment that makes genetic modifications to an embryo, which would be passed down to future generations.
The procedure has been successful in animals but has never been tested in humans.
Doug Turnbull, who leads the Newcastle team pioneering the procedure, said: "This is excellent news for families with mitochondrial disease. This will give women who carry these diseased genes more reproductive choice and the opportunity to have children free of mitochondrial disease."
However, Helen Watt at the Christian Anscombe Bioethics Centre in Oxford does not welcome the proposed treatment, claiming it involves the deliberate creation of an embryo "as a source of spare parts". She added: "Parenthood is about unconditional welcome of children. It is not about manufacture and control. Couples who do not want to take the risk of passing on mitochondrial disease might want to consider ethical alternatives like adoption, which are far preferable to pursuing dangerous techniques of genetic engineering which exploit both embryos and egg donors."
Sarah Norcross, director of the Progress Educational Trust, on the other hand, believes the treatment is something that should be pursued if it is found to be safe. "It would be unethical not to offer this treatment if it is safe and will help prevent children being born with serious disease. The other options are not great," she told the Guardian.
Has Voyager 1 left the Solar System?
Voyager 1 has travelled further from Earth than any other spacecraft and it has been claimed many times that the craft is on the verge of breaking out of the Solar System.
However, it still hasn’t made it, reported New Scientist. The problem is that no one’s certain where the edge of the Solar System actually is, only that it is where the influence of other stars will dominate the magnetic pull of the Sun – a magnetic bubble known as the heliopause.
Since 2005, Voyager 1 has been sending back signals that suggest changes in its surrounding environment – further readings were sent back last week – but the magnetic field has still not changed direction. So for the time being at least, Voyager 1 is still in our Solar System and not in interstellar space.