Science

We know that boys and girls are produced in much the same frequency. But how – and why – is this 1:1 ratio achieved?

A new paper searches huge human data sets for gene variants that throw the 1:1 sex ratio off balance, and test the biological and theoretical rules of sex ratio.

The 2024 Nobel Prize in physiology or medicine goes to Victor Ambros and Gary Ruvkun for their discovery of microRNA, tiny biological molecules that tell the cells in your body what kind of cell to be by turning on and off certain genes.

The Conversation Weekly podcast caught up with Victor Ambros from his lab at the UMass Chan Medical School to learn more about the Nobel-winning research and what comes next. Below are edited excerpts from the podcast.

How did you start thinking about this fundamental question at the heart of the discovery of microRNA, about how cells get the instructions to do what they do?

The paper that described this discovery was published in 1993. In the late 1980s, we were working in the field of developmental biology, studying C. elegans as a model organism for animal development. We were using genetic approaches, where mutations that caused developmental abnormalities were then followed up to try to understand what the gene was that was mutated and what the gene product was.

It was well understood that proteins could mediate changes in gene expression as cells differentiate, divide.

We were not looking for the involvement of any sort of unexpected kind of molecular mechanisms. The fact that the microRNA was the product of this gene that was regulating this other gene in this context was a complete surprise.

There was no reason to postulate that there should be such regulators of gene expression. This is one of those examples where the expectations are that you’re going to find out about more complexity and nuance about mechanisms that we already know about.

But sometimes surprises emerge, and in fact, surprises emerge perhaps surprisingly often.

Colorized scanning electron microscope image of a C. elegans nematode worm – one of the most studied animals in biological research. Steve Gschmeissner/Science Photo Library via Getty Images

These C. elegans worms, nematodes, is there something about them that allows you to work with their genetic material more easily? Why are they so key to this type of science?

C. elegans was developed as an experimental organism that people could use easily to, first, identify mutants and then study the development.

It only has about a thousand cells, and all those cells can be seen easily through a microscope in the living animal. But still it has all the various parts that are important to all animals: intestine, skin, muscles, a brain, sensory systems and complex behavior. So it’s quite an amazing system to study developmental processes and mechanisms really on the level of individual cells and what those cells do as they divide and differentiate during development.

Bottlenose dolphins in Sarasota Bay in Florida and Barataria Bay in Louisiana are exhaling microplastic fibers, according to our new research published in the journal PLOS One.

Tiny plastic pieces have spread all over the planet – on land, in the air and even in clouds. An estimated 170 trillion bits of microplastic are estimated to be in the oceans alone. Across the globe, research has found people and wildlife are exposed to microplastics mainly through eating and drinking, but also through breathing.

In my research focused on early farmers of Europe, I have often wondered about a curious pattern through time: Farmers lived in large dense villages, then dispersed for centuries, then later formed cities again, only to abandon those as well. Why?

Archaeologists often explain what we call urban collapse in terms of climate change, overpopulation, social pressures or some combination of these. Each likely has been true at different points in time.

Far beneath the lush landscape of southern China, a sprawling subterranean laboratory aims to be the world's first to crack a deep scientific enigma.

China has emerged as a science powerhouse in recent years, with the country's Communist leadership ploughing billions of dollars into advanced research to contend with the United States and other rivals.

Mosquito-borne illnesses are a growing concern in Northeastern states, with health officials monitoring cases and advising residents to avoid outdoor activities near standing water and other environments prone to mosquito spread.

Of particular concern is eastern equine encephalitis, a rare disease that can lead to serious and fatal illness, caused by mosquitoes carrying the virus.

The robot artist Ai-Da, a humanoid powered by artificial intelligence, will be the first of its kind to have a painting sold at a major auction house, organisers said Wednesday.

The work, due to go under the hammer at Sotheby's in London next month, is described as a "haunting" portrait of the English mathematician Alan Turing, considered one of the fathers of modern computing.

Viewed from above, Canada's newest Marine Protected Area (MPA) is deceptively simple: stretches of blue Pacific Ocean waters and a few patches of green forest.

But beneath the surface of the area known as the Great Bear Sea, off Vancouver Island, lies an area so rich in biodiversity it has been dubbed the "Galapagos of the North." It may also serve as a model for how to protect marine life elsewhere.

Some approaches to tackling global warming can have unintended knock-on consequences for nature and the protection of biodiversity, say scientists urging a more coordinated effort on these challenges.

"Sometimes by trying to find a solution to a problem, we risk creating damage elsewhere," Anne Larigauderie at the Intergovernmental Scientific and Political Platform on Biodiversity (IPBES), an expert independent body, told AFP.

More than half of the world's electricity will be generated by low-emission sources before 2030 but the deployment of clean energy is "far from uniform" across the globe, the International Energy Agency said Wednesday.

Demand for oil, gas and coal is still projected to peak by the end of the decade, possibly creating a surplus of fossil fuels, the IEA said in its annual World Energy Outlook.

Billions of years of evolution have made modern cells incredibly complex. Inside cells are small compartments called organelles that perform specific functions essential for the cell’s survival and operation. For instance, the nucleus stores genetic material, and mitochondria produce energy.

Another essential part of a cell is the membrane that encloses it. Proteins embedded on the surface of the membrane control the movement of substances in and out of the cell. This sophisticated membrane structure allowed for the complexity of life as we know it. But how did the earliest, simplest cells hold it all together before elaborate membrane structures evolved?

Only 37 percent of Europe’s surface waters are in good condition, warns the European Environment Agency. Climate change, habitat degradation, freshwater overuse and pollution are key threats. "Our waters face unprecedented challenges," said EEA Executive Director Leena Yla-Mononen, highlighting risks to Europe's water security.

Pollution, habitat degradation, climate change and over-use of freshwater resources are putting a strain on Europe, with only a third of its surface water in good health, the European Environment Agency warned on Tuesday.

A lone catamaran named "Silky" patrols waters around the remote island of Malpelo, a refuge that is protected yet full of peril for endangered marine species in the Colombian Pacific.

Its crew of environmentalists is the terror of boats illegally fishing for sharks inside the reserve some 500 kilometers (310 miles) off mainland Colombia -- one of the richest countries in terms of marine fauna.