Author: BBC World Service

The odds of becoming a fossil are vanishingly small. And yet there seem to be an awful lot of them out there. In some parts of the world you can barely look at a rock without finding a fossil, and museum archives worldwide are stuffed with everything from ammonites to Archaeopteryx. But how many does that leave to be discovered by future fossil hunters? What’s the total number of fossils left to find?

That’s what listener Anders Hegvik from Norway wants to know and what CrowdScience is off to investigate. Despite not having the technology or time to scan the entire planet, presenter Marnie Chesterton prepares to find a decent answer. During her quest, she meets the scientists who dig up fossils all over the world; does some very large sums; and asks, have we already found all the T-rexes out there?

Presented by Marnie Chesterton and produced by Anna Lacey

(Photo: Fossilized dinosaur bones and skull in the send. Credit: Getty Images)

Just over two months ago, the undersea volcano of Hunga Tonga erupted catastrophically, generating huge tsunamis and covering the islands of Tonga in ash. University of Auckland geologist Shane Cronin is now in Tonga, trying to piece together the sequence of violent events.

Edinburgh University palaeontologist Ornella Bertrand tells us about her studies of the ancient mammals that inherited the Earth after the dinosaurs were wiped out. To her surprise, in the first 10 million years after the giant meteorite struck, natural selection favoured larger-bodied mammals, not smarter ones.

At the University of Bristol, a team of engineers are developing skin for robots, designed to give future bots a fine sense of touch. Roland shakes hands with a prototype.

A global satellite survey of the world’s largest coastal cities finds that most of them contain areas that are subsiding faster than the rate that the sea level is rising. Some cities are sinking more than ten times faster, putting many millions of people at an ever-increasing risk of flooding. Oceanographer Steven D’Hondt at the University of Rhode Island explains why this is happening.

(Image: An eruption occurs at the underwater volcano Hunga Tonga-Hunga Ha"apai off Tonga, January 14, 2022. Credit: Tonga Geological Services/via Reuters)

Presenter: Roland Pease Producer: Andrew Luck-Baker

Russian forces in the forested exclusion zone around the Chernobyl nuclear site may be receiving potentially dangerous levels of radiation. After the nuclear accident trees were felled and radioactive material was buried across the site. As the forest regrew its took up much of that radiation - making it the most radioactive forest in the world according to Tom Scott from Bristol University who studies radiation levels in the region. The troop's activities, from digging trenches to lighting fires as missiles are fired, may be releasing radiation. Its unclear how dangerous this is, but those with the greatest and most immediate exposure risk are the troops themselves.

Australia’s iconic Great Barrier Reef has suffered a mass bleaching event – where coral can be killed by rising temperatures. This is the latest in a series of such events which also affect other reefs. Kate Quigley from The Australian Institute of Marine Science is working to breed corals that can be more heat tolerant. However, she says this is not a solution in itself without addressing climate change and continued ocean warming.

Understanding the human genome has reached a new milestone, with a new analysis that digs deep into areas previously dismissed as ‘junk DNA’ but which may actually play a key role in diseases such as cancer and a range of developmental conditions. Karen Miga from the University of California, Santa Cruz is one of the leaders of the collaboration behind the new findings.

And can fish do maths? Yes according to Vera Schlussel from the University of Bonn. Her group managed to train fish in both addition and subtraction. Many animals undertake remarkable migratory journeys; travelling thousands of miles only to return to same burrow or beach they departed from. Yet, unlike humans, they don’t have digital or paper maps to guide their way, so how are they able to orientate themselves with such accuracy?

In the second part of this migration story, CrowdScience’s Anand Jagatia explores how animals are able to navigate using the sun, stars, smells, landmarks and magnetism to help guide them. Anand journeys to the coast of Florida where he helps to place a satellite tracker on a sea turtle in order to follow the long-distance journeys of these animals. He then visits a lab in North Carolina to meet a team that is recreating the earth’s magnetic fields to examine how sea turtles might be using these forces to find their feeding and nesting grounds.

Anand wades into the hotly contested topic of just how birds may be sensing magnetic fields – and hears about one of the latest theories that suggests birds eyes may be exploiting quantum physics. The range of navigational tools we encounter throughout the animal kingdom from whales to ants is beguiling, Anand asks what does our increased understanding of these feats might mean for animal conservation as well as human development of mapping systems.

(Image: Radiation hazard sign in Pripyat, a ghost town in northern Ukraine, evacuated the day after the Chernobyl disaster. Credit: Getty Images)

Many animals undertake remarkable migratory journeys; travelling thousands of miles only to return to same burrow or beach they departed from. Yet, unlike humans, they don’t have digital or paper maps to guide their way, so how are they able to orientate themselves with such accuracy?

In the second part of this migration story, CrowdScience’s Anand Jagatia explores how animals are able to navigate using the sun, stars, smells, landmarks and magnetism to help guide them. Anand journeys to the coast of Florida where he helps to place a satellite tracker on a sea turtle in order to follow the long-distance journeys of these animals. He then visits a lab in North Carolina to meet a team that is recreating the earth’s magnetic fields to examine how sea turtles might be using these forces to find their feeding and nesting grounds.

Anand wades into the hotly contested topic of just how birds may be sensing magnetic fields – and hears about one of the latest theories that suggests birds eyes may be exploiting quantum physics. The range of navigational tools we encounter throughout the animal kingdom from whales to ants is beguiling, Anand asks what does our increased understanding of these feats might mean for animal conservation as well as human development of mapping systems.

Contributors: David Godfrey – Sea Turtle Conservancy Rick Herren – University of Florida Tim Guilford – University of Oxford Ken Lohmann – University of North Carolina Kayla Goforth – University of North Carolina Henrik Mouritsen – University of Oldenburg

(Photo: Sea Turtles. Credit: Getty Images)

Russian forces in the forested exclusion zone around the Chernobyl nuclear site may be receiving potentially dangerous levels of radiation. After the nuclear accident trees were felled and radioactive material was buried across the site. As the forest regrew its took up much of that radiation - making it the most radioactive forest in the world according to Tom Scott from Bristol University who studies radiation levels in the region. The troop's activities, from digging trenches to lighting fires as missiles are fired, may be releasing radiation. Its unclear how dangerous this is, but those with the greatest and most immediate exposure risk are the troops themselves.

Australia’s iconic Great Barrier Reef has suffered a mass bleaching event – where coral can be killed by rising temperatures. This is the latest in a series of such events which also affect other reefs. Kate Quigley from The Australian Institute of Marine Science is working to breed corals that can be more heat tolerant. However, she says this is not a solution in itself without addressing climate change and continued ocean warming.

Understanding the human genome has reached a new milestone, with a new analysis that digs deep into areas previously dismissed as ‘junk DNA’ but which may actually play a key role in diseases such as cancer and a range of developmental conditions. Karen Miga from the University of California, Santa Cruz is one of the leaders of the collaboration behind the new findings.

And can fish do maths? Yes according to Vera Schlussel from the University of Bonn. Her group managed to train fish in both addition and subtraction.

(Image: Radiation hazard sign in Pripyat, a ghost town in northern Ukraine, evacuated the day after the Chernobyl disaster. Credit: Getty Images)

Presenter: Roland Pease Producer: Julian Siddle

Wherever you are in the world you are probably near an animal that has undertaken a remarkable migratory journey, be that a butterfly, bird or sea turtle. But what CrowdScience listener Moses in Kenya wants to know is why they bother making such long and precarious voyages - and how they're able to reliably navigate over hundreds and sometimes even thousands of miles. In this first of two episodes, presenter Anand Jagatia travels to the Americas to meet the scientists finding and tracking these animals in order to solve the puzzle of where they go and why.

Deep in the lush and noisy Belizean jungle, Anand joins avian biologist Abidas who is collecting data on the beautiful birds that visit tropical forests to escape harsh winters. Here, using misting nets, Abidas and her team carefully catch birds to measure their health and status before tagging and releasing them so they can continue stocking up on jungle food. Anand finds out why having long term data on migrant birds can help in understanding why some birds, like the wood thrush, have been declining in their native homes further north.

Anand then jumps aboard a turtle boat in Florida where scientists from the Sea Turtle Conservancy have been collecting data on these dinosaur-like creatures. But finding them is harder it might seem. They move fast, so Anand accompanies the research team who are experienced in safely catching them, will he be lucky and find one of these magnificent creatures?

Presented by Anand Jagatia and produced by Melanie Brown

Contributors: David Barrie – Navigator & author Tim Guilford – University of Oxford Abidas Ash – University of Belize Kristen Ruegg - Colorado State University David Godfrey – Sea Turtle Conservancy

[Image credit: BBC Staff, Melanie Brown]