Dark Matter Halos of Newly Discovered Ultra-Diffuse Galaxies Are “Very Odd”

By UNIVERSITY OF CALIFORNIA - RIVERSIDE OCTOBER 17, 2022

The invisible halo that surrounds and permeates a galaxy or galaxy cluster is known as a dark matter halo

A University of California, Riverside physicist explains.

In a study co-led by physicists at the University of California, Riverside and the University of California, Irvine, it was discovered that the dark matter halos of ultra-diffuse galaxies are very odd, raising questions about the current understanding of galaxy formation and the universe’s structure.

The name “ultra-diffuse galaxies” refers to their exceedingly low luminosity. When compared to “normal” galaxies of comparable mass, the distribution of baryons — gas and stars — in ultra-diffuse galaxies is significantly more spread out.

Hai-Bo Yu is a theoretical physicist at UC Riverside. Credit: Samantha Tieu

In the following Q&A, Hai-Bo Yu, an associate professor of physics and astronomy at UCR, discusses the findings he and UCI’s Manoj Kaplinghat, a long-term colleague of Yu’s, published in The Astrophysical Journal regarding newly found ultra-diffuse galaxies and their dark matter halos.

Demao Kong of Tufts University, as well as Filippo Fraternali and Pavel E. Mancera Pia of the University of Groningen in the Netherlands, collaborated with Yu and Kaplinghat on the study. Kong, the first author, will join UCR this fall.

Q. What is a dark matter halo?

A dark matter halo is the halo of invisible matter that permeates and surrounds a galaxy or a cluster of galaxies. Although dark matter has never been detected in laboratories, physicists are confident dark matter, which makes up 85% of the universe’s matter, exists.

Q. You’ve found dark matter halos of the ultra-diffuse galaxies are very odd. What is odd about them and what are you comparing them to?

The ultra-diffuse galaxies we studied are much less massive compared to, say, the Milky Way. They contain a lot of gas, however, and they have much higher gas mass than total stellar mass, which is opposite to what we see in the Milky Way. The ultra-diffuse galaxies also have large sizes.

The distribution of dark matter in these galaxies can be inferred from the motion of gas particles. What really surprises us is that the presence of baryonic matter itself, predominantly in the form of gas, is nearly sufficient to explain the measured velocity of gas particles and leaves little room for dark matter in the inner regions, where most of the stars and gas are located.

This is very surprising because, in the case of normal galaxies, whose masses are similar to those of ultra-diffuse galaxies, it’s the opposite: dark matter dominates over baryonic matter. To accommodate this result, we conclude that these dark matter halos must have much lower “concentrations.” That is, they contain much less mass in their inner regions, compared to those of normal galaxies. In this sense, dark matter halos of the ultra-diffuse galaxies are “odd.”

At first glance, one would expect that such low-concentration halos are so rare that the ultra-diffuse galaxies would not even exist. After looking into the data from state-of-the-art numerical simulations of cosmic structure formation, however, we found the population of low-concentration halos is higher than the expectation.

Q. What was involved in doing the study?

This is a collaborative work. Filippo Fraternali and his student Pavel E. Mancera Piña are experts on the gas dynamics of galaxies. They discovered that ultra-diffuse galaxies rotate more slowly than normal galaxies with similar masses. We worked together to interpret measurement data of the gas motion of these galaxies and infer their dark matter distribution. Furthermore, we analyzed data from simulations of cosmic structure formation and identified dark matter halos that have similar properties as those inferred from the ultra-diffuse galaxies.

Q. Your findings raise questions about our understanding of galaxy formation/structure formation of the universe. How?

We have many questions regarding the formation and evolution of these newly discovered galaxies. For example, ultra-diffuse galaxies contain a lot of gas and we do not know how this gas is retained during galaxy formation. Further, our results indicate that these galaxies may be younger than normal galaxies. The formation of the ultra-diffuse galaxies is not well understood, and more work is needed.

Q. What makes ultra-diffuse galaxies so interesting?

These are amazing objects to study because of their surprising properties, as discussed in our work. The newly discovered ultra-diffuse galaxies provide a new window for further testing our understanding of galaxy formation, probably even the nature of dark matter.

Reference: “The Odd Dark Matter Halos of Isolated Gas-rich Ultradiffuse Galaxies” by Demao Kong, Manoj Kaplinghat, Hai-Bo Yu, Filippo Fraternali and Pavel E. Mancera Piña, 12 September 2022, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ac8875

The study was funded by the National Science Foundation, the United States Department of Energy, the John Templeton Foundation, and NASA.

Tongkat Ali Explored: Wellness Scam or Testosterone-Boosting Miracle Supplement?

By SCITECHDAILY.COM OCTOBER 17, 2022

There has been a lot of buzz about Tongkat Ali on the internet lately. Over recent months, the compound, derived from the Southeast Asian Eurycoma longifolia plant, has soared in popularity for its supposed health and hormonal benefits. Still, a fair bit of suspicion has also made its way into the conversation. Tongkat Ali skeptics sight several concerns regarding its potential long-term health consequences and a shortage of scientific evidence supporting its safety and efficacy. With that said, it is time to take a closer look at Tongkat Ali and see what all the fuss is really about.

Tongkat Ali (Eurycoma longifolia) is a medium-sized slender shrub that is native to Indochina (Cambodia, Laos, Malaysia, Myanmar, Thailand and Vietnam) and Indonesia (the islands of Borneo and Sumatra). It is also known as pasak bumi or longjack. The root of the plant has been used in folk medicine of the South East Asian region, and in modern times has common use as supplements.

What Is Tongkat Ali?

Tongkat Ali, also known as Longjack, is an herbal treatment derived from the roots of the Eurycoma longifolia plant of Southeast Asia. It has been used in several Southeast Asian countries (e.g., Indonesia, Vietnam, and Malaysia) for decades to treat a range of ailments, including infections, fevers, and impotence. However, since its meteoric rise in popularity amongst an increasingly Western demographic, most of the focus has shifted away from its medicinal benefits and towards its potential to boost testosterone, manage stress, enhance sexual function, and aid in building muscle. So what does ‘the science’ say?

Does it Work?

A handful of studies on humans and mice has shown moderate amounts of improvement in mood regulation, erectile function, libido, and most surprisingly of all, testosterone. For example, a 2013 study of 63 individuals (32 males and 31 females) found a 37% increase in testosterone status after only four weeks of use (Talbott et al., 2013). A similar study out of the world-renowned andrology journal, Andrologia, found that among a sample of thirty-two males in their mid-twenties, both testosterone and free testosterone levels dramatically increased by 15% and 34%, respectively (Chan et al., 2021). Studies show many other positive impacts from using Tongkat Ali, including stress reduction, mood improvements, increased energy levels, and libido enhancement (Tambi et al., 2018).

What Do The Doubters Think?

Despite an emerging body of research supporting the efficacy of Tongkat, a solid number of individuals are still lukewarm towards its supposed benefits. For starters, only a handful of Tongkat Ali studies use human respondents, while the rest were largely animal-based studies. Detractors often reference the scarce body of literature in humans as a reason to be concerned about the long-term side effects of supplementing with Tongkat Ali. Likewise, existing side effects associated with Tongkat Ali can include insomnia, restlessness, and, ironically enough, elevated anxiety levels despite its supposed stress reduction properties. Increases in testosterone could also worsen pre-existing conditions such as heart disease, hormone-sensitive cancers, and sleep disorders, so folks who suffer from any of these illnesses should be wary of supplements containing Tongkat Ali (Wong, 2021). Lastly, it is essential to remember that the FDA does not regulate nutritional supplements such as Tongkat Ali, meaning concerns over harmful ingredients and additives are common.

Some Final Thoughts

A modest body of scientific literature seems to support the efficacy of Tongkat Ali. But specific questions surrounding possible short-term and long-term side effects remain unanswered. And while you will undoubtedly find a ton of positive user reviews, YouTube testimonies, and health forum discussions online, it is up to you and your primary care physician to decide whether or not Tongkat Ali is right for you.

References:

1. Chan, Kai Quin, et al. “The Effect of Eurycoma Longifolia on the Regulation of Reproductive Hormones in Young Males.” Andrologia, vol. 53, no. 4, 2021, p. E14001.
2. Talbott, Shawn M., et al. “Effect of Tongkat Ali on Stress Hormones and Psychological Mood State in Moderately Stressed Subjects.” Journal of the International Society of Sports Nutrition, vol. 10, 2013, p. 28. PubMed Central.
3. Tambi, M. I. B. M., et al. “Standardised Water-Soluble Extract of Eurycoma Longifolia, Tongkat Ali, as Testosterone Booster for Managing Men with Late-Onset Hypogonadism?” Andrologia, vol. 44, 2012, pp. 226-30.
4. Wong, Cathy. “What Do Tongkat Ali Supplements Do?” Verywell Fit, 2021. Accessed 16 January 2022.

COVID-19 Pandemic Caused “Unprecedented” Shock Decline in Life Expectancy

By UNIVERSITY OF OXFORD OCTOBER 17, 2022

According to new research, the COVID-19 pandemic has caused a protracted shock to life expectancy levels, leading to global mortality changes unprecedented in the last 70 year

• Most of Western Europe experienced life expectancy bouncebacks in 2021
• Scale of Eastern Europe losses akin to the mortality crisis at the break-up of the Soviet Union
• Countries with higher proportions of fully vaccinated people generally experienced smaller life expectancy deficits

COVID-19 has caused a protracted shock to life expectancy levels, leading to global mortality changes unprecedented in the last 70 years, according to research that will be published today (October 17) in the journal Nature Human Behaviour from Oxford’s Leverhulme Centre for Demographic Science and the Max Planck Institute for Demographic Research.

Using data from 29 countries in Europe, as well as Chile and the US, the researchers found life expectancy in 2021 remained lower than expected across all 29 countries, had pre-pandemic trends continued

Previous global epidemics have seen fairly rapid “bounce backs” to life expectancy levels. But the scale and magnitude of COVID-19, on mortality, confounds claims it has had no more impact than a flu-like illness. Life expectancy losses during recurring flu epidemics over the second half of the 20^th century have been much smaller and less widespread than those seen in the pandemic.

A clear geographical divide appeared in 2021. The researchers found most countries in Western Europe experienced life expectancy bounce-backs from the sharp losses in 2020. Sweden, Switzerland, Belgium, and France saw complete bouncebacks, returning to pre-pandemic 2019 life expectancy levels. While England and Wales saw partial bounce-backs from 2020 levels in 2021. Life expectancy in Scotland and Northern Ireland, however, remained at the same depressed level as 2020. 

But Eastern Europe and the US witnessed worsening or compounded losses in life expectancy over the same period. The scale of life expectancy losses during the COVID-19 pandemic in Eastern Europe were akin to those last seen at the break-up of the Soviet Union, according to the research.

This East-West divide in life expectancy during COVID-19 generally reflects bigger losses in countries that had lower pre-pandemic life expectancy levels. Bulgaria was the worst-hit of the countries studied, with a decline in life expectancy of nearly 43 months, over two years of the pandemic. According to the paper, “Bulgaria, Chile, Croatia, Czech Republic, Estonia, Germany, Greece, Hungary, Lithuania, Poland, and Slovakia suffered substantially higher life expectancy deficits in 2021 compared to 2020, indicating a worsening mortality burden over the course of the pandemic.”

In addition to pre-pandemic life expectancy, there appeared to be a vaccination effect that followed the same East-West divide in Europe. Countries with higher proportions of fully vaccinated people experienced smaller life expectancy deficits. Older ages, especially those over 80 who had seen the bulk of deaths in 2020, benefitted from vaccine protection and a decline in excess mortality in 2021.

Dr. Ridhi Kashyap, a study co-author from Oxford, points out, “A notable shift between 2020 and 2021 was that the age patterns of excess mortality shifted in 2021 towards younger age groups, as vaccines began to protect the old.”

But there were “outliers,” which had surprisingly high life expectancy losses, in spite of high vaccination rates. Dr. Jonas Schöley, study co-author from the Max Planck Institute, says, “Finer-grained details of the age prioritization of vaccine roll-out and the types of vaccines used may account for some of these differences, as well as correlations between vaccine uptake and compliance with non-pharmaceutical interventions or the overall health care system capacity.”

He adds, “Countries, such as Sweden, Switzerland, Belgium, and France, managed a recovery to pre-pandemic levels of life expectancy because they managed to protect both the old and the young.”

The research team voices concern, however, about the possible wider international impact of the pandemic. Another study co-author, Dr. José Manuel Aburto, maintains, “In 2020, losses in life expectancy suffered in Brazil and Mexico exceeded those experienced in the US, so it is likely these countries may have continued suffering mortality impacts in 2021 – even potentially exceeding the 43 months we estimated for Bulgaria.”

The paper concludes, “It is plausible that countries with ineffective public health responses will see a protracted health crisis induced by the pandemic with medium-term stalls in life expectancy improvements, while other regions manage a smoother recovery to return to pre-pandemic trends.”

Reference: “Life expectancy changes since COVID-19” 17 October 2022, Nature Human Behaviour.
DOI: 10.1038/s41562-022-01450-3 

Scientists Solve an Origin of Life Mystery

By UNIVERSITY OF CAMBRIDGE OCTOBER 18, 2022

The discoveries may alter scientists’ perceptions of the environments in which life initially originated

Seawater might have supplied the phosphorus required for emerging life.

Researchers from the Universities of Cambridge and Cape Town may have found a solution to the mystery of how phosphorus came to be an essential component of life on Earth by recreating prehistoric seawater containing the element in a laboratory.

Their findings, which were published in the journal Nature Communications, suggest that seawater may be the missing source of phosphate, suggesting that it could have been present in sufficient quantities to support life without the need for particular environmental conditions.

“This could really change how we think about the environments in which life first originated,” said Professor Nick Tosca from the University of Cambridge, who was one of the authors of the study.

The research, which was headed by University of Cambridge Ph.D. student Matthew Brady, reveals that early seawater may have carried 1,000–10,000 times more phosphate than previously thought, provided the water contained a lot of iron. 

Phosphate is a crucial component of DNA and RNA, which are the building blocks of life, although it is one of the least common elements in the universe relative to its biological significance. Phosphate is also relatively inaccessible in its mineral form – it can be difficult to dissolve in water so that life can utilize it.

Scientists have long suspected that phosphorus became part of biology early on, but they have only recently begun to recognize the role of phosphate in directing the synthesis of molecules required by life on Earth, “Experiments show it makes amazing things happen – chemists can synthesize crucial biomolecules if there is a lot of phosphate in solution,” said Tosca, Professor of Mineralogy & Petrology at Cambridge’s Department of Earth Sciences.

However, there has been debate over the precise circumstances required to create phosphate. According to some research, phosphate should actually be even less accessible to life when iron is plentiful. However, this is disputed since the early Earth’s atmosphere was oxygen-poor and iron would have been widespread.

They used geochemical modeling to simulate the early Earth’s conditions in order to understand how life came to rely on phosphate and the kind of environment that this element would have evolved in.

“It’s exciting to see how simple experiments in a bottle can overturn our thinking about the conditions that were present on the early Earth,” said Brady.

In the lab, they made up seawater with the same chemistry thought to have existed in Earth’s early history. They also ran their experiments in an atmosphere starved of oxygen, just like on ancient Earth.

The team’s results suggest that seawater itself could have been a major source of this essential element.

“This doesn’t necessarily mean that life on Earth started in seawater,” said Tosca, “It opens up a lot of possibilities for how seawater could have supplied phosphate to different environments— for instance, lakes, lagoons, or shorelines where sea spray could have carried the phosphate onto land.”

Previously scientists had come up with a range of ways of generating phosphate, some theories involving special environments such as acidic volcanic springs or alkaline lakes, and rare minerals found only in meteorites.

“We had a hunch that iron was key to phosphate solubility, but there just wasn’t enough data,” said Tosca. The idea for the team’s experiments came when they looked at waters that bathe sediments deposited in the modern Baltic Sea. “It is unusual because it is high in both phosphate and iron — we started to wonder what was so different about those particular waters.”

In their experiments, the researchers added different amounts of iron to a range of synthetic seawater samples and tested how much phosphorous it could hold before crystals formed and minerals separated from the liquid. They then built these data points into a model that could predict how much phosphate ancient seawater could hold.

The Baltic Sea pore waters provided one set of modern samples they used to test their model with, “We could reproduce that unusual water chemistry perfectly,” said Tosca. From there they went on to explore the chemistry of seawater before any biology was around.

The results also have implications for scientists trying to understand the possibilities for life beyond Earth. “If iron helps put more phosphate in solution, then this could have relevance to early Mars,” said Tosca.

Evidence for water on ancient Mars is abundant, including old river beds and flood deposits, and we also know that there was a lot of iron at the surface and the atmosphere was at times oxygen-poor, said Tosca.

Their simulations of surface waters filtering through rocks on the Martian surface suggest that iron-rich water might have supplied phosphates in this environment too.

“It’s going to be fascinating to see how the community uses our results to explore new, alternative pathways for the evolution of life on our planet and beyond,” said Brady.

Reference: “Marine phosphate availability and the chemical origins of life on Earth” by Matthew P. Brady, Rosalie Tostevin, and Nicholas J. Tosca, 2 September 2022, Nature Communications.
DOI: 10.1038/s41467-022-32815-x

IT'S EXACTLY WHAT I THINK

Why Are Drugs So Expensive? It’s Not What You Think

PROFITEERING

By UNIVERSITY OF CALIFORNIA - SAN DIEGO OCTOBER 18, 2022

Costly research and development aren’t necessarily why drugs are so expensive.

Pharmaceutical companies argue that high drug prices are required to recuperate the expenses of research and development, but researchers discovered no relationship between the two.

A multinational team of scientists examined whether high R&D (research and development) expenditures account for high drug prices in the United States in the first known study of its kind.

“There is a presumption that high R&D costs justify high drug prices. If that were true, then we’d see a positive association between the two measures,” said first author Olivier Wouters, Ph.D., assistant professor at the London School of Economics and Political Sciences.

Inmaculada Hernandez, PharmD, PhD, is an associate professor at Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego and senior author of a study that found high drug prices are not associated with the costs of research and development. Credit: UC San Diego Health Sciences

But in a paper recently published in the journal JAMA Network Open, Wouters and colleagues from the University of California San Diego’s Skaggs School of Pharmacy and Pharmaceutical Sciences discovered no such association for 60 new drugs approved by the US Food and Drug Administration from 2009 to 2018.

The researchers compared information on drug pricing and R&D expenditures. They discovered no connection between pharmaceutical corporations’ R&D spending and the prices they charge for new drugs. The therapeutic value of a product was also evaluated by the researchers, but they discovered no link between therapeutic value and price. 

“Our findings provide evidence that drug companies do not set prices based on how much they spent on R&D or how good a drug is. Instead, they charge what the market will bear,” said senior author Inmaculada Hernandez, PharmD, Ph.D., associate professor at Skaggs School of Pharmacy and Pharmaceutical Sciences.

The Congressional Budget Office estimates that the pharmaceutical sector spent $83 billion on research and development in 2019. It is estimated that companies spend between $1 billion and $3 billion on average to bring a single new product to market. According to the database company Statista, the U.S. pharmaceutical industry earned more than $490 billion in sales in 2019, making up close to half of the worldwide pharmaceutical market.

Americans spend more on prescription drugs per capita than citizens in any other country. In 2019, that worked out to more than $1,200 per person. A 2021 Rand Corporation study found U.S. drug prices were 2.56 times higher than those in 32 comparable countries. A Kaiser Family Foundation Health Tracking Poll published earlier this year found that eight in 10 adults said the cost of prescribed medications was unreasonable.

Legislators in Congress have in recent years introduced numerous proposals intended to apply downward pressure on drug prices. Pharmaceutical companies and trade groups have opposed these reforms, arguing that high drug prices are needed to recover R&D investments.

“If this argument is to be used to justify high prices and oppose measures to curb prescription drug costs, drug companies should supply further data to support their claims that high drug prices are needed to recover R&D investments,” said Hernandez.

Reference: “Association of Research and Development Investments With Treatment Costs for New Drugs Approved From 2009 to 2018” by Olivier J. Wouters, Ph.D., Lucas A. Berenbrok, PharmD, MS, Meiqi He, MS, Yihan Li, BS and Inmaculada Hernandez, PharmD, Ph.D., 26 September 2022, JAMA Network Open.
DOI: 10.1001/jamanetworkopen.2022.18623

The study authors acknowledged that the analysis was limited by the small sample size.

Why Do Humans Walk Upright? Harvard Biologists Reveal the Secret

By HARVARD UNIVERSITY OCTOBER 19, 2022

In comparison to chimpanzees and gorillas, the shorter and wider reorientation of our pelvic blades allows humans to walk or balance more easily

A new study demonstrates how the pelvis evolved for upright walking.

If evolutionary biologist Terence D. Capellini were to rank the body parts that define us as human, the pelvis would be towards the top.

After all, thanks to its design, humans can walk upright on two legs (unlike our primate cousins) and mothers can give birth to children with huge heads (therefore big brains). The pelvis is anatomically well-understood, but when it comes to how and when this very essential structure takes form throughout development, our understanding begins to falter.

That is changing thanks to recent research by Capellini’s team. The study, which was published in the journal Science Advances, demonstrates when the pelvis forms during pregnancy and identifies the genes and genetic sequences that drive the process. The research may one day provide insight into the genetic origin of bipedalism and pave the way for the development of treatments or predictors of hip joint disorders, like hip dysplasia and hip osteoarthritis.

“This paper is really focused on what all humans share, which are these changes to the pelvis that allowed us to walk on two legs and allowed us to give birth to a large fetal head,” said Capellini, a newly tenured Professor in the Department of Human Evolutionary Biology at Harvard University and senior author on the study.

The study shows that many of the features essential for human walking and birth form around the 6- to 8-week mark during pregnancy. This includes key pelvic features unique to humans, like its curved and basin-like shape. The formation happens while bones are still cartilage so they can easily, curve, rotate, expand, and grow.

The researchers also discovered that when other cartilage in the body starts to transform into bone, the developing pelvic region remains as cartilage for a longer period of time, allowing it to mature properly.

“There appears to be a stalling that happens and this stalling allows the cartilage to still grow, which was pretty interesting to find and surprising,” Capellini said. “I call it a zone of protection.”

The researchers used RNA sequencing to determine which genes in the area are actively triggering pelvic formation and slowing ossification, which usually converts softer cartilage to hard bone. They discovered hundreds of genes that are turned either on or off throughout the 6- to 8-week period to form the ilium in the pelvis, which is the largest and uppermost bone of the hip with blade-like structures that curve and rotate into a basin to support walking on two legs.

Compared to chimpanzees and gorillas, the shorter and wider reorientation of our pelvic blades makes it so humans don’t have to shift the mass of our weight forward and use our knuckles to walk or balance more comfortably. It also helps increase the size of the birth canal. Apes on the other hand have much narrower birth canals and more elongated ilium bones.

The researchers started the study by comparing these differences in hundreds of skeletal samples of humans, chimpanzees, and gorillas. The comparisons demonstrated the striking effects that natural selection has had on the human pelvis, the ilium in particular.

To see when the ilium and pelvic elements forming the birth canal began to take shape, the researchers examined 4- to 12-week-old embryos under a microscope with the consent of people who had legally terminated their pregnancies. The researchers then compared samples from the developing human pelvis’ with mouse models to identify the on and off switches triggering the formation.

The work was led by Mariel Young, a former graduate researcher in Capellini’s lab who graduated in 2021 with her Ph.D. The study was a collaboration between Capellini’s lab and 11 other labs in the U.S. and around the world. Ultimately, the group wants to see what these changes mean for common hip diseases.

“Walking on two legs affected our pelvic shape, which affects our disease risk later,” Capellini said. “We want to reveal that mechanism. Why does selection on the pelvis affect our later disease risk of the hip, like osteoarthritis or dysplasia? Making those connections at the molecular level will be critical.”

Reference: “The developmental impacts of natural selection on human pelvic morphology” by Mariel Young, Daniel Richard, Mark Grabowski, Benjamin M. Auerbach, Bernadette S. de Bakker, Jaco Hagoort, Pushpanathan Muthuirulan, Vismaya Kharkar, Helen K. Kurki, Lia Betti, Lyena Birkenstock, Kristi L. Lewton and Terence D. Capellini, 17 August 2022, Science Advances.
DOI: 10.1126/sciadv.abq4884

The study was funded by Harvard University, the National Science Foundation, and the Milton Fund, 

Co-Existence of Modern Humans and Neanderthals in France and Northern Spain

By SCIENTIFIC REPORTS OCTOBER 19, 2022

According to a modeling study, modern humans may have co-existed with Neanderthals in France and northern Spain for between 1,400 and 2,900 years before Neanderthals disappeared.

For between 1,400 and 2,900 years before Neanderthals disappeared, modern humans may have co-existed with Neanderthals in France and northern Spain. This is according to a new modeling study that was published on October 13 in Scientific Reports. These findings increase our understanding of the existence of the two species of humans in this region.

Modern humans (Homo Sapiens) and Neanderthals (Homo neanderthalensis) may have co-existed in Europe for as long as 5,000 to 6,000 years before Neanderthals became extinct, according to recently uncovered fossil evidence. However, there is currently little evidence for their co-existence at a regional level. Moreover, it is difficult to establish when the two species first appeared and disappeared in these areas.

In the new study, Igor Djakovic and colleagues analyzed a dataset of 56 Neanderthal and modern human artifacts (28 for each group) from seventeen archaeological sites across France and northern Spain, as well as an additional ten Neanderthal specimens from the same region. For greater accuracy, all samples had been radiocarbon-dated using robust modern techniques since 2000. 

The authors used Optimal Linear Estimation and Bayesian probability modeling to estimate the date ranges for these samples and the populations responsible, and infer the earliest and latest dates that these human groups might have been present at the sites. This modeling served to fill in missing portions of the archaeological record, which hamper date estimation.

Based on this modeling, the authors estimate that Neanderthal artifacts first appeared between 45,343 and 44,248 years ago, and disappeared between 39,894 and 39,798 years ago. The date of Neanderthal extinction, based on directly-dated Neanderthal remains, was between 40,870 and 40,457 years ago. Modern humans were estimated to first appear between 42,653 and 42,269 years ago. The authors conclude that this suggests the two species of humans co-existed in these regions for between 1,400 and 2,900 years. These results do not, however, indicate how or whether modern humans and Neanderthals interacted.

Reference: “Optimal linear estimation models predict 1400–2900 years of overlap between Homo sapiens and Neandertals prior to their disappearance from France and northern Spain” by Igor Djakovic, Alastair Key and Marie Soressi, 13 October 2022, Scientific Reports.
DOI: 10.1038/s41598-022-19162-z

Ocean Heating Will Increase Monsoon Rainfall in East Asia

By RUTGERS UNIVERSITY OCTOBER 19, 2022

Upper ocean heating in the equatorial Pacific is likely to make the East Asian monsoon season wetter, according to a new study.

Stronger winds and warming of the upper ocean layers in the western tropical Pacific have been linked to increased rain in eastern China.

According to new research, upper ocean heating in the equatorial Pacific – a key oceanographic region in Earth’s climate system – is likely to make the East Asian monsoon season wetter.

Recent increases in ocean heat content – where energy is absorbed by the waters – have been implicated in the intensification of tropical storms that draw their energy from the surface of the ocean. However, the link between ocean heating and rainfall on land is less clear. A study co-authored by a Rutgers researcher provides insight into this link. It will be published today (October 19) in the journal Nature.

“Our study suggests variations in ocean thermal structure affect the delivery of moisture, latent heat, and what happens when they arrive on land,” said Yair Rosenthal. He is a professor of marine and coastal sciences in the Rutgers’ School of Art and Sciences and School of Environmental and Biological Sciences.

Rosenthal said the changes in the latitudinal temperature gradient – the difference in sea-surface temperature between low and high latitudes – not only control how energy is absorbed by the equatorial upper ocean but how winds carry the moisture from the ocean onto land.

The study, which was led by Zhimin Jian of Tongji University in China, found that over the past 360,000 years, increases in monsoonal rain in eastern China correlated with increases in the heat content of the Indo-Pacific Warm Pool–a region where sea surface temperatures remain above ~82°F (~28°C) year-round–likely due to enhanced transport of moisture and latent heat absorbed in the water vapor from the ocean to the continent.  

According to the study, the changes in upper ocean heat content follow shifts in the Earth’s orbit that occur about every 23,000 years and change the distribution of incoming solar radiation at each latitude.

By using two foraminifera species, calcareous marine organisms, one a surface dweller and the other that lives approximately 200 meters below the sea surface, the scientists reconstructed how the upper ocean thermal structure gets its heat and energy. They compared their results with climate model simulations and reconstructions of the monsoonal precipitation in eastern China for the same period.

The coupling of ocean heat content and monsoon variations, both coordinated by insolation changes at astronomical timescales, is critical for regulating the global hydroclimate, the researchers said.

Reference: 19 October 2022, Nature.
DOI: 10.1038/s41586-022-05302-y

Co-authors include Zhimin Jian, Yue Wang, Haowen Dang, Zhongfang Liu, Haiyan Jin, Liming Ye, Xingxing Wang of Tongji University; Mahyar Mohtadi of the University of Bremen; David Lea of the University of California, Santa Barbara; and Wolfgang Kuhnt of Christian-Albrechts-University.