Author: BBC World Service

Five years ago, people around the world were enduring COVID lockdowns as we attempted to prevent the spread of the virus. Today, many of those who caught COVID-19 are still suffering from lingering symptoms, including a loss of their sense of smell. And that got the Unexpected Elements team thinking about all things olfactory.

First up, hold your noses as we investigate the two chemicals that make up the scent of death.

Next, are you prone to telling lies? Well, research suggests that your nose might give you away!

We then turn our attention to the cinema to find out more about the chemicals you release during a scary film.

We’re also joined by chemist Professor Matija Strlic, who reveals how he can detect aromas in ancient Egyptian mummies and – crucially – tells us why he wants to do this.

That, plus many more Unexpected Elements.

Presenters: Marnie Chesterton, with Kai Kupferschmidt and Affelia Wibisono Producers: Alice Lipscombe-Southwell, with William Hornbrook, Debbie Kilbride, Imaan Moin and Noa Dowling

There is continued upheaval in US scientific institutions under the new Trump administration. This week $400 million dollars-worth of grants have been frozen at Columbia University in response to “illegal” protests on the campus. President Trump also recently accused the Biden Administration of spending $8 million dollars on "transgender mice" experiments. We talk to two scientists, Kelton Minor and Patricia Silveyra, who have been affected in different ways.

Also, as the first data from the European Space Agency's Euclid mission is released, Euclid project leader Valeria Pettorino tells us how this impressive space telescope hopes to unlock the secrets of the dark universe.

And, around this time last year we heard about the H5N1 strain of bird flu finally jumping to the Antarctica Peninsula. Today, an expedition led by virologist Antonio Alcami confirms that the virus has spread to every animal species at each site they visited.

Presenter: Roland Pease Producer: Ella Hubber Production co-ordinator: Jana Holesworth and Josie Hardy

(Photo: University of Minnesota researchers, scientists and other supporters protest against President Donald Trump's proposed scientific research funding cuts. Credit: Michael Siluk/Getty Images)

CrowdScience listener Alina is in a relationship with a polyamorous partner and is very happy with this arrangement, which got her thinking – why is monogamy so often the norm in human societies?

Presenter Caroline Steel goes on an anthropological odyssey to figure out where this drive to find a single partner - and stick with them - comes from.

What can science tell us about how human relationships developed, and whether having one or many partners is more 'natural'?

Evolutionary biologist Kit Opie of the University of Bristol joins us at London Zoo to help us understand the mating systems of our closest primate relatives.

To find out how polygamy developed in some parts of the world we speak to anthropologist Katie Starkweather of the University of Illinois Chicago.

And we learn about the chemistry of bonding from Sarah Blumenthal at Emory University, who explains how the brains of prairie voles may give us clue about the neurochemicals which shape human relationships.

Presenter: Caroline Steel Producers: Priya Sippy, Ben Motley and Imaan Moin Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Steve Greenwood

(Image: Dancing wedding cake figurines Credit: Peter Dazeley via Getty Images)