Consensus Science Digest January 2025

Hello! Welcome to Consensus Digest. This month we look at some of the first science stories of 2025, including how microplastics affect mice brains, how ‘paraparticles’ may defy the norms of theoretical physics, and how the LA wildfires may be connected to climate change.

BY DR. EVA HAMRUD: I am a bioinformatician with a primary research interest in stem cell biology. I am also passionate about all areas of scientific research and their communication.

 

HEALTH

Microplastics Accumulate in Mouse Brains

Microplastics are tiny pieces of plastic less than 5 millimeters across. They can be found when plastic items like bottles, bags and packaging break down. Microplastics have been found in oceans, sea ice and the atmosphere, as well as in drinking water, cosmetic products, food items and even in human blood. Despite their widespread presence both around and within us, the health effects of microplastics remain poorly understood.

In a study published in Science Advances in January 2024, researchers from Peking University in Beijing, China, used high-resolution imaging techniques to show that microplastics accumulate in mouse brains. To visualise the process in real-time, the researchers surgically implanted a transparent window in the skulls of the mice. Then they introduced fluorescent microplastics to the mice’s drinking water, and tracked the fluorescent signal as it entered the brain’s blood vessels. After roughly two hours, fluorescent microplastics were observed circulating in the bloodstream, and within an hour after that, fluorescent cells began appearing. This indicated that certain cells had engulfed the microplastics. Upon further investigation, these cells were identified as immune cells, which typically ‘eat’ foreign particles in the bloodstream to defend the body against infection.

Surprisingly, the fluorescent immune cells behaved abnormally – they tended to become lodged in the brain’s blood vessels. While some cells were trapped for only a few minutes, others remained stuck for weeks. The researchers noted that the most sticky cells exhibited an altered shape compared to cells that were transiently stuck, and larger microplastic particles led to a greater number of blockages. Since blood vessels play a crucial role in delivering oxygen to the brain, mice with blocked vessels displayed neurobehavioral issues, such as reduced mobility.

It is unclear why microplastics cause immune cells to obstruct brain blood vessels. It is possible that the microplastics activate signaling pathways that make the cells sticky, physically alter the cells’ shape, or a combination of these factors. The researchers also speculated that similar blockages could occur in other organs, such as the heart, but further studies would be needed to confirm this. Whether the same process happens in humans remains uncertain. One notable difference is that human blood vessels are wider than those in mice, potentially making them less prone to blockages.

Despite these remaining questions, this work highlights a growing need to study the potential impacts of microplastics on the environment and on human health. Understanding these effects is essential for identifying potential risks and developing strategies to mitigate them.

 

PHYSICS

Researchers Describe How ‘Paraparticles’ Might Exist

In quantum physics, particles are typically classified as fermions or bosons. Fermions, such as electrons and protons, have half-integer spins and adhere to the Pauli exclusion principle, which means they can’t share the same quantum state. Bosons, like photons, have integer spins and can occupy the same quantum state, enabling phenomena like lasers. In the 1950s, physicists introduced the concept of ‘paraparticles’ as a theoretical extension beyond these two categories. Unlike fermions and bosons, paraparticles are hypothesized to follow different statistical rules, known as ‘parastatistics’, which could lead to unique behaviors.

Initially, paraparticles were extensively studied by the high-energy physics community. However, by the 1970s, mathematical studies suggested that these paraparticles were actually just bosons or fermions, with the exception of anyons that can only exist in two dimensions. In new research published in Nature earlier this month, theoretical physicists at Rice University have described a new mathematical framework for paraparticles. These new parastatistics suggest that paraparticles could exist in any number of dimensions. This work brings us a step closer to understanding new types of particles, some of which may be used in quantum computing in the future.

 

ARCHEOLOGY

Uncovering The Egalitarian World of Cucuteni Trypillian Culture

The oldest cities in the world – Mesopotamia, Ancient Egypt, the Indus Valley, and Ancient China – are often celebrated as the “cradles of civilization.” These societies, dating back around 5,000 years, left behind evidence of advanced craftsmanship, architecture, and engineering. However, researchers have turned their attention to an even older culture: the Cucuteni-Trypillian culture, which thrived about 6,000 years ago in present-day Moldova, Romania, and Ukraine. One of the largest known Cucuteni-Trypillian settlements, Maidanets’ke, consisted of 3,000 houses and was home to an estimated 11,000 people. Despite their impressive scale, these settlements are classified as “megasites” or “urban settlements” rather than cities. A key distinction is the lack of evidence for social hierarchy, unlike the structured societies of Mesopotamia or Ancient Egypt.

The Cucuteni-Trypillian culture was first identified in the late 19th century, with initial sites discovered at Cucuteni in Romania and Trypilla in Ukraine. These sites were later revealed to be part of a vast pre-Bronze Age culture that spanned 350,000 square kilometers. This culture is renowned for its sophisticated pottery, particularly its stylized figurines of curvaceous women.

In addition to their pottery, the Cucuteni-Trypillian people employed unique city-planning techniques. Settlements, including Maidanets’ke, were arranged in concentric rings with open central spaces. Houses were uniform in size and contained similar quantities of pottery and artifacts, suggesting an egalitarian society. To explore wealth inequality, researchers used house floor sizes as a proxy for household wealth. A study of approximately 7,000 houses across 38 settlements found that wealth inequality decreased over time until around 3,800 BCE, when it began to rise slightly before the culture’s decline. The reasons for the culture’s disappearance after this time remain uncertain, with hypotheses ranging from climate change to increasing inequality which may have caused societal collapse.

The Cucuteni-Trypillian culture stood in stark contrast to the rigid hierarchies of Mesopotamia and Ancient Egypt. The fact that this culture thrived for thousands of years raises intriguing questions about the possibility of large, organized communities living in harmony without social stratification.

 

CLIMATE

LA Fires Spread as Earth Warms to 1.5°C Above Pre-industrial Levels

The Los Angeles wildfires, which began on January 7, 2025, have resulted in at least 24 fatalities and the destruction of over 12,000 structures, which are predicted to cost tens of billions of dollars to rebuild. The destruction has so far been caused by multiple wildfires, with the largest, the Palisades Fire, having burned 23 thousand acres of land. Scientists attribute the severity of these fires to a combination of factors, including severe drought conditions and powerful Santa Ana winds.

While we cannot attribute climate change as the cause for these specific wildfires, it is well accepted that global warming increases the likelihood of wildfires around the world. At the beginning of 2025, multiple independent bodies officially announced that 2024 saw our planet’s average temperature rise exceed 1.5°C above pre-industrial levels. 1.5°C was the internationally agreed-upon limit from the Paris 2015 climate accord, and many scientists hope that hitting this limit will increase the urgency for climate change action.

 

NATURE ODDITIES

Flower Pollinates Itself Using a Finger-like Appendage

Stigmatodactylus sikokianus is a small orchid first discovered in 1890. This orchid has an unusual finger-like appendage beneath its stigma – the female reproductive structure of flowers. Its name reflects this distinctive trait, combining ‘Stigmato‘ for the stigma and ‘dactylus‘ which means ‘finger’ in Greek. This month, over 100 years after its discovery, the purpose of this curious appendage has finally been uncovered.

Many plants rely on insects for pollination, but as Stigmatodactylus sikokianus thrives on the dark forest floor and lacks nectar to entice visitors, it needs an alternative strategy. In an article published earlier this month, a researcher from Kobe University in Japan observed that, when no insects pollinated the orchid, it began to wilt. As it wilts, the finger-like appendage comes into contact with the stigma, effectively forming a bridge to allow the plant to self-pollinate. Although self-pollination is well-documented in some plant species, this bridging mechanism has never been observed before. This finding highlights that we still have much to learn about the ingenious methods plants can employ to survive and reproduce in different environments.

 

CONSENSUS ANSWER OF THE MONTH

How can we solve the reproducibility crisis?

Solving the reproducibility crisis requires a combination of increased transparency, methodological innovation, and collaborative efforts across the scientific community. By adopting open practices, improving research designs, and fostering a culture of reproducibility, the scientific community can enhance the reliability and impact of research findings.

 

 

REFERENCES Microplastics World Economic Forum article Environmental International research article – microplastics in human blood Nature news article Science Advances research article Paraparticles Nature news article Nature research article Scitech daily news article Cucuteni-Trypilla culture New Scientist news article Nature feature article Cambridge University Press research article LA Wildfires BBC News article Nature News 1.5C Self-pollinating orchid New Scientist news article EurekAlert news article Plants, People, Planet research article