It's getting so bad that - according to the World Wildlife Fund - the average person is ingesting up to a credit card's worth of plastic each week. Now a new major scientific review links microplastics to lung and colon cancer.
An interview with the main researcher on ABC radio
https://www.abc.net.au/listen/programs/radionational-breakfast/microplastics-health-harms/104749826
Some points from the article:
Most scientific papers are incremental and rarely make headlines, with only a few results reaching the public. To assess scientific news, consider the timeline. Significant findings often build on years of research and also the scope, since broader claims usually lack robust support. Patience is essential - scientific conclusions are built via debate and scrutiny and evolve. While some science is just too incomplete to reach firm conclusions yet. The evidence is still accumulating. Like claims about the small-brained human relative Homo naledi. Did they make art, use fire, and bury their dead as claimed? Probably, but it's too soon to say for sure.
Examples from the article include the South Pole telescope finding primordial waves from the earliest moments of the Big Bang - which sadly was just local dust. Also the phosphine in the Venusian atmosphere which the discoverers proposed came from some form of exotic life floating in the cloud tops. That was just flawed methodology.
Exciting research is often incorrect due to speculative ideas or over-narrow parameters. But speculation is needed. "if we knew the answers ahead of time, we wouldn’t need to do science". Scientists also face pressure to publish high-impact results. That can lead to exaggerated findings or even fraud. Additionally, media sensationalism can distort scientific reporting. Trust in science has declined as contradictory claims in the media promote doubt about the scientific method. Some discoveries, like gravitational waves, are compelling and well-founded, but most intriguing results need caution.
Its a nice bit of tech. 73M in construction costs. The focal plane instrumentation alone weighs 10 tonnes. It includes 5,000 small computer controlled fiber positioners. The entire focal plane can be reconfigured for the next exposure in less than two minutes while the telescope slews to the next field. The DESI instrument is capable of taking 5,000 simultaneous spectra of different Galaxies
The DESI Collaboration (https://en.wikipedia.org/wiki/Dark_Energy_Spectroscopic_Instrument) has released results from its first year of observations.
“The complex analysis used nearly 6 million galaxies and quasars and lets researchers see up to 11 billion years into the past. With just one year of data, DESI has made the most precise overall measurement of the growth of structure, surpassing previous efforts that took decades to make.” According to Dragan Huterer, professor at the University of Michigan and co-lead of DESI’s group.
https://web.ub.edu/en/web/actualitat/w/desi-force-gravity - New DESI results on the force of gravity
The analysis upholds general relativity but hints dark energy may vary over time. The result validates our leading model of the universe. It limits theories of modified gravity like MOND, which have been proposed as alternative ways to explain unexpected observations – including the accelerating expansion of our universe attributed to dark energy.
The standard model of cosmology summarizes our current best knowledge of the Universe. This is based on two well-established pillars of physics. Einstein's General Relativity, which regulates gravitation, and the standard model of particle physics, for all other basic interactions. However, it also relies on three key components — Inflation, Dark matter, and Dark energy that are critical for understanding a wide range of evidence, from the Cosmic Microwave Background to the Universe's Large Scale Structure.
The Dark Energy Spectroscopic Instrument (DESI) measures the effect of dark energy on the universe's expansion. Its completed survey will obtain optical spectra for tens of millions of galaxies and quasars, constructing a 3D map of the nearby universe.
“This is the first time that DESI has looked at the growth of cosmic structure. We’re showing a tremendous new ability to probe modified gravity and improve constraints on dark energy models. And it’s only the tip of the iceberg.”
Additional details on the implications for alternative gravity models in this paper - Ishak et al. (2024), Modified Gravity Constraints from the Full Shape Modeling of Clustering Measurements from DESI 2024 https://arxiv.org/abs/2411.12026
Links to the other original papers are here https://data.desi.lbl.gov/doc/papers/
Also, for those concerned that Human brains have shrunk over the last thirty thousand years, there is good news: A large-scale study published in March 2024 by researchers at UC Davis Health found human brains have been getting larger over the last few decades. Study participants born in the 1970s had 6.6% larger brain volumes and almost 15% larger brain surface area than those born in the 1930s. This steady increase for people born after the 1930s, is believed to be due to better nutrition. https://health.ucdavis.edu/news/headlines/human-brains-are-getting-larger-that-may-be-good-news-for-dementia-risk/2024/03
Discoveries about a young ancestor's teeth may shed light on the upward trend in brain size over millennia.
Other explanations
Bipedalism developed long before bigger brains, and the use of tools was widespread in earlier hominid branches. As a result, these causes have been ruled out as the main driving force in brain evolution, despite being essential preconditions. https://efossils.org/book/bipedalism-vs-brain-size
Preteen teeth
The recent study of the 1.77 Million-year-old remains of an 11 to 12-year-old early homo from the Dmanisi site in Georgia is significant. https://phys.org/news/2024-11-fossil-teeth-childhood-prelude-evolution.html. This study of dental development throws some light on another human oddity, which is our very extended childhoods. The fossil's age places it close to the emergence of larger brains in our ancestors. A useful timeline is found here https://australian.museum/learn/science/human-evolution/larger-brains/
For context that's around this point in Human Evolution
Modern Human life history is distinguished by a prolonged childhood in which mental and somatic development rates diverge. This slow development is crucial for developing high cognitive abilities in our socially complex species.
A slowing childhood in a supportive family and cultural transmission
This individual experienced rapid growth in their first five years, faster than in apes. For example, their wisdom teeth fully emerged at 12 years of age compared to 17-24 today. This rapid growth was unexpected given the age of the fossil and its relationship to modern humans. However, the teeth did have a sequence of growth similar to modern humans. Marcia Ponce de León from the University of Zurich and co-author of the study commented "Milk teeth were used for longer than in the great apes and the children of this early Homo species were dependent on adult support for longer than those of the great apes". She suggests that "This could be the first evolutionary experiment of prolonged childhood".
It is believed that children's development slowed as cultural transmission increased, making the quantity of knowledge conveyed from old to young more crucial. This transmission would have allowed them to make greater use of available resources while developing more sophisticated behaviours, providing them with an evolutionary advantage.
The demands of large brains cause Humans to develop more slowly than our closest animal cousins. Energy directed toward the brain dominates the human body's metabolism early in life, which is possibly one other reason why humans develop at a rate more akin to a reptile than a mammal in early childhood. A five-year-old's brain is a real energy monster. It uses twice as much glucose as a fully grown adult. See https://www.sciencedaily.com/releases/2014/08/140825152558.htm
What does this explain?
However, just identifying some of the forces influencing the brain's evolution does not account for the emergence of more recent advances such as symbolic language. https://www.britannica.com/science/human-evolution/Language-culture-and-lifeways-in-the-Pleistocene Nonetheless, the brain's expansion was an essential precursor to the richness of human culture. Even in this early era of human evolution where children needed to mature rapidly, and life expectancy was low, adult care exerted a protective effect.
Additional Info
A variety of circumstances probably influenced brain development, including contributions from diverse hominid lineages with larger brains that were previously lumped into a single smaller smaller-brained species. Ian Tattersall provides a nuanced discussion of brain size and how it relates to humanities tangled origins in this 2023 article: Endocranial volumes and human evolution, https://pmc.ncbi.nlm.nih.gov/articles/PMC10517302/
Tau seems like the only remaining target for treating alzheimers so it good to see a new drug thats active in that space. Antiamyloid treatments have been ineffective. Interesting that it strenthens healthy tau structures rather than reducing overall levels of this useful/vital molecule Compared to this drug https://www.ucl.ac.uk/news/2023/apr/first-gene-silencing-drug-alzheimers-disease-shows-promise for example