A former Russian spy, Sergei Skripal, and his daughter Yulia are in a serious condition after being exposed to a nerve agent on Sunday. The first police officer to attend the scene also remains in hospital. It is being treated as 'a major incident involving attempted murder.' We ask what happens next: what antidotes are available, how do they work and what's the prognosis?

Today marks International Women’s Day. Its aim is to celebrate the social, economic, cultural and political achievements of women. But there’s also a strong call for change, especially in the tech industry where women are vastly underrepresented. Discussions on how we could achieve gender equality have been ongoing for years, so why has there been so little change? And how can this bias affect the technology we all use?

Scientists are warning of an infertility 'crisis' among men. Sperm counts have been falling for over 40 years and now, 1 in 20 men have low sperm counts. The cause is unknown and this week, doctors are calling for more funding to better understand the issue.

The red squirrel has found an unlikely ally: the pine marten. Grey squirrels were introduced to the UK in the late 1800s from America and have since caused the native red population to diminish. However, with the reintroduction of a predator, the mal-adapted greys are being hunted and as a result, red squirrels are bouncing back.

With many parts of the country seeing large snowfalls we ask what's driving our current weather? What factors need to be in place to create snowfalls, and how do these differ from sleet or frozen rain? And we address the impact of climate change, while a series of weather events might show a pattern, at what point should we go looking for explanations beyond natural events?

Dutch Elm Disease laid waste to millions of British Elm trees back in the 1970's, Now a new tree bacteria which mimics the effects of drought has spread from the Americas to Europe. It has already been detected in some tree imports to the UK. Unlike Dutch Elm Disease it affects a huge variety of trees and shrubs, from mighty oaks to fruit trees and Lavender bushes. New directives have just been introduced to try and halt its spread.

Can we beat dementia? Research from the US amongst people in their 80's and 90's provides grounds for optimism, showing that elderly people with good memories have brain structures which can be more developed than those of people 30 years younger. And yet at the same time they may carry factors usually associated with dementia.

And how violent are we? Compared with our past that is. Research from collections of gruesome medieval remains paint a picture of a violent society, where men and women commonly carried weapons and inflicting or receiving severe wounds may have been a part of daily life. And yet other studies suggest this level of violence is actually lower than that experienced in some societies today.

Marnie Chesterton presents.

The UK is one of the largest recipients of research funding in the EU. Marnie Chesterton discusses what the future of UK science funding will look like with MP Norman Lamb, who chairs the House of Commons Science and Technology Committee, and Ed Whiting, Director of Policy and Chief of Staff at the Wellcome Trust.

Around 4,500 years ago, 90% of the British population was replaced by incomers known as the Beaker people. Across Europe archaeologists have uncovered elements of the Beaker culture - bell-shaped pots, copper daggers, arrowheads, stone wrist guards and distinctive perforated buttons -it's always been a mystery as to whether these finds represent a wave of mass migration or the sharing of ideas between peoples. Now ancient DNA studies show it was both, and for Britain reveal a huge population change which still resonates today.

A new collaboration between an artist and a cyclone physicist commences this week.They joined forces to model Hurricane Katrina and cast its shape into six brass bells. Each bell represents a key moment from the category 5 storm, as it progressed across the Gulf of Mexico and made landfall in the United States in 2005. The finished collection will feature in a BBC Radio 4 documentary later this year.

And how does the moon affect life on earth? specifically worms - we unearth a species of worm that times its mating ritual by the waxing and waning Moon.

Sulphur belched out of vessels' smokestacks is a serious health problem for coastal communities around the world. Four hundred thousand premature deaths from lung cancer and cardiovascular disease and around 14 million childhood asthma cases annually are reckoned to be related to shipping emissions. The International Maritime Organisation has finally agreed to drastically reduce polluting emissions from 2020. Gareth Mitchell discusses with James Corbett of the University of Delaware the impact of the emissions reduction on health.

The nearly complete skeleton of Cheddar Man was found in a cave in Somerset in 1903. He'e been in the news because experts in human face reconstruction have created an image of what he probably looked like based on new DNA evidence. Chris Stringer, Ian Barnes and Selina Brace of the Natural History Museum have all worked with Cheddar Man and they talk to Gareth about how the study of this 10 000 year old skeleton is part of a bigger project to understand how Britain became populated with waves of peoples from Europe in the Mesolithic and Neolithic eras.

Scientists at the Max Planck Institute for Intelligent Systems have invented a magnetically controlled soft robot only four millimetres in size that can walk, crawl or roll through uneven terrain, carry cargo, climb onto the water surface, and even swim in it. Professor Metin Sitti, Director of the Physical Intelligence Department at the Max Planck Institute, explains how it works and how he sees the future use of millirobots in medicine - in delivering drugs and targeting cancerous cells.

Marnie Chesterton talks to Dr Lisa Wallis from ELTE University in Hungary about her work to improve the cognitive abilities of older dogs... using touchscreens.

This week a US based billionaire launched a giant space rocket and sent a car vaguely in the direction of Mars. As a space mission it was to say the least unconventional, and for those involved in promoting space science it presents a quandary. Is such a mission largely a publicity stunt or is it useful for engaging people in the potential of space exploration? Gareth Mitchell looks at one project which enables schoolchildren to programme computers on the International Space Station and he talks to the European Space Agency about why a rock concert might be a good avenue for exploring space science.

As more and more of our everyday lives are conducted online we ask what are the cyber-security threats of today, and how can science be used to counter them. Do we now need new kinds of science to locate, understand and stop new kinds of threat?

Can bat science help human ageing research? New findings have show that some long lived bat species do not age in the same way as other mammals. They don't even seem to posses the DNA repair enzyme most commonly found in the animal kingdom. We look at the mystery of why bats seem to have evolved in this way.

And have you lost a satellite? Don't worry: a computer geek will find it for you. That's exactly what's happened - an amateur space sleuth has detected signals from a NASA satellite thought to have been 'lost' for years.

In 2016 there was an attempted coup in Turkey. This led to many people who the government saw as opposition figures being sacked from their jobs and in some cases held without trial. They include prominent intellectuals, medics and scientists. In recent days there has been a similar crackdown on people voicing criticism of Turkey's current military actions in Syria.

It's the 60 years since the launch of Explorer 1 and the discovery of the Van Allen Belts. This was the satellite the US launched in response to Sputnik. However unlike Sputnik it did undertake scientific exploration, its findings have been significant for every space mission that followed.

Using DNA sequencing scientists have found that the 'Two Brothers' mummies at the Manchester Museum have different fathers so are, in fact, half-brothers. Khnum-nakht and Nakht-ankh - date to around 1800 BC. Ever since their discovery in 1907 there has been some debate amongst Egyptologists on whether the two were actually related at all. DNA was extracted from their teeth to solve the mystery.

And the science of the Archers, a current storyline involves leaks of industrial chemicals illegally buried on a farm many years ago. We'll be looking behind the scenes to see where the story came from and how the world's longest running soap opera ensures scientific accuracy.

This week's programme is presented by Gareth Mitchell as Adam is away.

What killed the Aztecs? In some areas of the Americas, as many as 95% of the indigenous population died of diseases brought in by the discoverers of the New World. Pandemics hit the population who had little immunity to diseases carried by people and livestock. One outbreak responsible for killing millions started in 1545 and was locally called 'cocoliztli'. But for the last 500 years, exactly what this deadly disease was has remained a mystery. Adam talks to Johannes Krause of the Max Planck Institute who has analysed the teeth of 10 individuals from a mass grave for pathogens and found remnants of typhoid fever DNA. Could this be, in part, responsible for the deaths of millions? Historian Caroline Dodds Pennock from the University of Sheffield discusses the difficulties of knowing for definite what killed so many millions of people.

In 2015, Nick Goldman issued a challenge. If anyone could decode the information he had stored on some DNA by 21st January 2018, they could win a bitcoin. When Nick bought the bitcoin it cost about £200. To claim the bitcoin, the winner would have to sequence the DNA and then decrypt a code. In late 2017, Nick thought he would be keeping his bitcoin, now worth thousands of pounds. But PhD student Sander Wuyts got in touch with Nick to claim his prize. Marnie Chesterton follows the story.

Adam talks to MIT scientist, Michael Strano about his new techniques to make plants glow in the dark. Could these plants be used as street lighting in the future?

And how can sound be used to levitate humans? Professor of Ultrasonics at the University of Bristol, Bruce Drinkwater explains how his team have managed to overcome a size limit on the use of acoustic beams to trap and move objects in space. With no theoretical upper limit on the size of object which can be levitated, he explains how the technology could be used in medicine to deliver powerful drugs to a very specific place. This would leave the rest of the body unharmed or could help in the dispersal of kidney stones.

African Swine fever is deadly to pigs and is spreading west from Russia across Europe. The virus that causes it is very resilient and can stick around on clothing, hay and in infected pork products for as long as 150 days. Biosecurity is crucial to preventing its arrival in the UK. If just one pig eats some infected meat from discarded human food the disease could quickly spread causing thousands of pigs to be culled and costing the industry millions. But what is the current progress on developing a vaccine? Adam talks to virologist Professor Jonathan Ball of Nottingham University and Zoe Davies from the National Pig Association.

Simon Boxall from Southampton Oceanography Centre gives an update on the sinking of the oil tanker Sanchi and its environmental impact.

CRISPR is a revolutionary gene editing technique which can modify DNA and has the potential to correct genetic errors in a range of human diseases - even cancer. The technique has only been around for a few years but is already being talked about as a Nobel prize winning candidate. The market for the technology has been predicted to be worth US$ 10 billion by 2025. But stocks took a wobble last week on news that our immune system may render CRISPR useless. Is there really a big problem? Adam talks to Matt Porteus from Stanford University who did the research.

18 months ago, New Zealand announced a conservation project to exterminate all vermin that are decimating the indigenous bird population. For millions of years, the flora and fauna evolved in isolation, without predatory mammals. When humans arrived, they brought with them a host of bird-eating animals like rats, stoats and possums which now kill 25 million native birds every year. Marnie Chesterton travelled to New Zealand to report on a campaign of mass poisoning to save the kiwis and the kakapos and asks whether it’s ethical to kill one species to save another.

And Cat Hobaiter from St Andrews University responds to listener questions about how chimpanzees might recognise family members.

After the Sanchi oil tanker collided with another ship it discharged its cargo of 1 million barrels of condensate oil. This could cause one of the biggest oil disasters in 25 years. What is condensate, can it be cleaned up and how toxic to marine life is it if large amounts of it leak or the tanker sinks? Adam talks to Simon Boxall from Southampton Oceanography Centre.

A long-held belief that babies look more like their fathers is being put to the test by scientists at St Andrews University. They are launching an on-line citizen science experiment asking members of the public to see if they can tell from a group of chimps which are the close relations. Geoff Marsh takes the test and talks to researcher Cat Hobaiter about why it might be advantageous for a baby primate to look like its father more than its mother and what they hope to learn from humans' ability to recognise chimp family trees.

A new swallow-able, electronic pill that sniffs out the gas produced in your gut could be the answer to accurately diagnosing and distinguishing between ailments of the gut. The gastrointestinal tract is hard to access so when something goes wrong, conditions like Irritable Bowel Syndrome, lactose intolerance and over production of bacteria. can be hard to distinguish from one another and so accurately diagnosed. Professor Kourosh Kalantar Zadeh from RMIT in Melbourne explains why his device, which senses gases in the gut and transmits its findings back to a smartphone in real time,, is more accurate and less invasive than current breath tests or endoscopies and colonoscopies.

And Janet Kelso answers listener questions on human evolution and why modern Europeans still carry Neanderthal DNA.

Adam Rutherford talks to astronomer Tabetha Boyajian at Louisiana State University about the wierd star that's perplexed astronomers since its discovery two years ago. KIC 8462852 has the unique habit of intermittently and sometimes dramatically dimming and then brightening. Some scientists even suggested vast alien megastructures around the star might be the explanation. After twenty months of almost continuous observation, Professor Boyajian has much more information about what the star is doing. But the big mystery hasn't gone away.

BBC News science correspondent Jonathan Amos joins Adam to share some highlights in space exploration for the coming 12 months.

Zoologists and engineers at the University of Oxford are developing an app that identifies one species of mosquito from another by analysing the sounds their rapid wing beats make. Graihagh Jackson visits Marianne Sinka at the Zoology Department to listen to her collection of mosquito songs.

Did the widespread introduction of the food additive trehalose fuel the emergence of epidemics of virulent Clostridium difficile in hospitals from the early 2000s? Microbiologist Robert Britton tells Adam about the evidence his team has gathered and published this week in the journal 'Nature'.