BBC Inside Science

When the news broke last December that Chinese biophysicist He Jiankui had successfully edited the genomes of twin girls using the technique known as CRISPR-Cas9, scientists and the public were rightly outraged that such a procedure had taken place. Jiankui is currently being investigated by Chinese authorities for breaking legal and ethical guidelines on human genome editing. This week, in the journal Nature, several top scientists have called for a global moratorium on gene editing in the clinic. Which might be surprising, because we thought these rules were already in place. Dr. Helen O’Neill, a Lecturer in Reproductive and Molecular Genetics at UCL explains to Adam Rutherford what the current rules are, and they debate whether we need a ‘voluntary moratorium’. It’s hard to miss the current discussions on sex, gender, and biology. One arena where debates are getting quite heated is sport. In 2016, the International Olympic Committee announced that male-to-female transgender athletes will be allowed to compete in the Tokyo Olympics in 2020, without having gender reassignment surgery. They do have to demonstrate reduced blood testosterone levels (usually achieved through hormone therapy). Female-to-male transgender athletes can compete ‘without restriction’. Gerard Conway, Professor of Reproductive Endocrinology at the Institute for Women’s Health at University College London, joins Adam to help us understand many of the issues concerning testosterone and its putative effect on athletic performance. The festival hog roast has been happening for more than four and a half thousand years. Hundreds of pig bones have been unearthed from henge sites including Durrington Walls near Stonehenge in Wiltshire – and these have helped put together a picture of life in Neolithic Britain, especially when people came together from all over the country, and brought pigs with them for big feasts. Dr. Richard Madgewick at Cardiff University carried out isotopic analysis on the pig bones to work out just how far people travelled with their pigs to attend these social events. Producer: Fiona Roberts

An HIV-1 sufferer, who had developed aggressive cancer, and underwent a revolutionary stem cell transplant, has been declared HIV resistant. It's been 18 months since the 'London patient' underwent a stem cell transplant of donated HIV resistant cells. This has only happened once before, in the case of the ‘Berlin Patient' – who, after two transplants, has now been HIV and cancer free for 10 years. Professor Ravindra Gupta at Cambridge University is careful not to say the work carried out at UCL has ‘cured’ the patient, but it’s very promising. They say they have made the patient’s cells ‘resistant’ to infection by the HIV virus. There are no animals that do not need sleep, yet we're still not sure why we need to sleep. Giorgio Gilestro at Imperial College has been trying to find out more about whether lack of sleep shortens lifespan, by bothering fruit flies and stopping them dropping off. In a carefully designed experiment, he has devised a way of shaking the flies as soon as it looks like they are dropping off. He tells Gareth Mitchell that he's 98% certain the flies were kept awake day after day and discovered that there was no life-shortening effect due to lack of sleep. He cannot rule out the benefit of micro-sleep, but it provides tantalising results which could point us in the direction of finally discovering whether we need those 8 precious hours a night. Eight years ago, on 11th March 2011, three of the nuclear reactors overheated and exploded at the Fukushima nuclear plant in Japan. This was following the tsunami that killed around 19,000 people. The essentials are known – the reactors overheated when the cooling circuits failed. The overheated steam then broke down into hydrogen and oxygen, which then caught fire and blew the reactor vessels apart. But the details aren’t known. And there’s no way of getting inside the reactors to learn them. So instead researchers are doing a forensic analysis of the radioactive debris scattered around the reactor sites – some of it at the Diamond X-ray facility just outside Oxford. Roland Pease was waiting in the experimental area as one grain of Fukushima dust was brought in from safe storage. Concerned about a growing number of spurious scientific claims on products and campaigns against vaccinations and the shape of our planet, climate scientist Ben McNeil decided to do something about it. He has come up with a website where anyone can pose a question for scientists to answer. MetaFact.io is just starting up, but Ben's hope is to put the public in direct contact with the scientists with some, if not all, of the answers.

Efforts to cut emissions of carbon dioxide (CO2) and tackle climate change in many developed economies are beginning to pay off, according to research led by Corinne Le Quere at the Tyndall Centre at the University of East Anglia. The study suggests that policies supporting renewable energy and energy efficiency are helping to reduce emissions in 18 developed economies. The group of countries represents 28% of global emissions, and includes the UK, US, France and Germany. The research team analysed the various reasons behind changes in CO2 emissions in countries where they had declined significantly between 2005 and 2015. They show that the fall in CO2 emissions was mainly due to renewable energy replacing fossil fuels and to decreasing energy use. Methane is many times more potent a greenhouse gas than carbon dioxide. However, it breaks down much more quickly than CO2 and is found at much lower levels in the atmosphere. During much of the 20th century levels of methane, mostly from fossil fuel sources like coal and gas, increased in the atmosphere but, by the beginning of the 21st century, they had stabilised. Then, surprisingly, levels starting rising in 2007. That increase began to accelerate after 2014 and fast growth has continued. Studies suggest these increases are more likely to be mainly biological in origin. However, the exact cause remains unclear. Some researchers believe the spread of intense farming in Africa may be involved, in particular in tropical regions where conditions are becoming warmer and wetter because of climate change. Rising numbers of cattle – as well as wetter and warmer swamps – are producing more and more methane. This idea is now being studied in detail by a consortium led by Professor Euan Nisbet, at Royal Holloway, University of London. Another, more worrying source for the increase in methane could be that it’s not been broken down in the atmosphere as efficiently. Natural chemicals in the atmosphere, which help to break down methane, may be changing because of temperature rises, causing them to lose their ability to deal with the gas. The Francis Crick Institute is a biomedical discovery institute researching the biology underlying human health. This vital research is carried out by some of the best scientists in their field. However, many, many more people are involved behind the scenes. ‘Craft and Graft’ is a new exhibition at the Francis Crick Institute celebrating these ‘unsung heroes’, and opens on 1 March, focusing the spotlight on the technicians, engineers and support staff that are vital in supporting the scientists and their work by ensuring the glassware is washed, the equipment runs smoothly and the cells are all looked after and categorised correctly. Hannah Fisher was granted special access behind the scenes to meet some of the people who inspired the exhibition. Producer: Fiona Roberts

Nasa have called time on the 14 year mission with the Mars Opportunity rover. Curiosity is still there. But what's next for our exploration of the Red planet? Adam asks Senior Strategist in Space Systems at Airbus, Liz Seward and BBC space correspondent, Jonathan Amos. Airbus are working with the European and Russian Space Agencies on the next rover, part of the Exomars mission. This new rover is called the Rosalind Franklin, after the UK scientist and when it hopefully lands in 2021, it'll be drilling down, deep into the surface of Mars to look for evidence of past life. We know that trees help mitigate the effects of greenhouse gases on climate change by sucking up carbon dioxide from the atmosphere. In fact forests are estimated to lock up 2 of every 10 carbon molecules released. But which forests do it best? Tom Pugh at the University of Birmingham has been looking at the age of forests to try and see if this is a factor. It turns out the pristine, ancient tropical forests like the Amazon, although doing a good job, just aren't as good as the younger, regrowth forests of the Boreal and Temperate zones in the northern hemisphere. It's all down to demographics and the balance between new trees and dying trees. We keep hearing that this, or that, species is being threatened by climate change, but often the mechanisms are not that obvious. One particularly intriguing example comes in the form of the Ethiopian bush crow. An intelligent, seemingly adaptable bird, living in what seems like a general, widespread habitat in Southern Ethiopia, eating a wide and varied diet. Yet it's range is restricted to tiny pockets of land in a huge area of, what seems like a similar habitat. Ecologist, Andrew Bladon at Cambridge University thinks he has the answer to what's restricting this bird's range and how is a warming climate pushing this bird to extinction. Producer: Fiona Roberts

A very strongly worded, meta-review paper (looking at 73 historical reports from around the world published over the past 13 years) has just been published looking at the fate of insects around the world. The researchers have collated other people’s research, including the big 27 year study from Germany, that showed 75% loss of insects by weight (biomass). The basic headlines are quite scary: 40% of insect species are declining; 33% are endangered; we’re losing a total mass of 2.5% of insects every year. The reviewers blame habitat loss by conversion to intensive agriculture as the main driver for the declines, plus agro-chemicals, invasive species and climate change adding to the burden. Adam Rutherford speaks to insect expert Professor Adam Hart from the University of Gloucestershire to discuss numbers and consequences. It’s quickly being realised that the composition of microbes in our guts is vital to our health. Scientists working on the gut microbiome have discovered and isolated more than 100 completely new species of bacteria from healthy human intestines. It’s hoped that these new techniques to isolate and grow these novel bugs, will give us insight into how our microbiome keeps us healthy. After covering the story about the Earth’s early core accretion and the clues found in rocks about the early magnetic field, listener Neil Tugwell emailed BBC Inside Science to ask for more information about geomagnetic switching. Are we heading for another flip of the magnetic poles? And what might be the impact on GPS? Adam gets the answers from Dr. Robert Wicks, lecturer in space risk in the UCL Institute for Risk and Disaster Reduction. Producer: Fiona Roberts