Lifeboat Foundation

Denisovan DNA lives on in some humans today because, once our Homo sapien ancestors encountered the Denisovans, they had sex with them and gave birth to babies — something geneticists call admixture. By analyzing current-day genetic data, we can look back into human history.

Geneticists have found that a Philippine ethnic group known as the Ayta Magbukon has the highest level of Denisovan ancestry in the world.

At the center of galaxies, like our own Milky Way, lie massive black holes surrounded by spinning gas. Some shine brightly, with a continuous supply of fuel, while others go dormant for millions of years, only to reawaken with a serendipitous influx of gas. It remains largely a mystery how gas flows across the universe to feed these massive black holes.

UConn Assistant Professor of Physics Daniel Anglés-Alcázar, lead author on a paper published today in The Astrophysical Journal, addresses some of the questions surrounding these massive and enigmatic features of the universe by using new, high-powered simulations.

“Supermassive black holes play a key role in galaxy evolution and we are trying to understand how they grow at the centers of galaxies,” says Anglés-Alcázar. “This is very important not just because black holes are very interesting objects on their own, as sources of gravitational waves and all sorts of interesting stuff, but also because we need to understand what the central black holes are doing if we want to understand how galaxies evolve.”

When plants first ventured onto the land, evolving from freshwater-dwelling algae, more than 500 million years ago, they transformed the planet. By drawing carbon dioxide from the air, they cooled Earth, and by eroding rock surfaces they helped build the soil that now covers so much land.

These changes to the planet’s atmosphere and land surface paved the way for the evolution of the biosphere we know. Land plants make up around 80 percent of Earth’s biomass.

The pioneering plants were small and moss-like, and they had to overcome two big challenges to survive on land: avoiding drying out, and surviving the Sun’s harsh ultraviolet light.

Widespread human SARS-CoV-2 infections combined with human-wildlife interactions create the potential for reverse zoonosis from humans to wildlife. We targeted white-tailed deer (Odocoileus virginianus) for serosurveillance based on evidence these deer have ACE2 receptors with high affinity for SARS-CoV-2, are permissive to infection, exhibit sustained viral shedding, can transmit to conspecifics, and can be abundant near urban centers. We evaluated 624 pre-and post-pandemic serum samples from wild deer from four U.S. states for SARS-CoV-2 exposure. Antibodies were detected in 152 samples (40%) from 2,021 using a surrogate virus neutralization test. A subset of samples was tested using a SARS-CoV-2 virus neutralization test with high concordance between tests. These data suggest white-tailed deer in the populations assessed have been exposed to SARS-CoV-2.

One-Sentence Summary Antibodies to SARS-CoV-2 were detected in 40% of wild white-tailed deer sampled from four U.S. states in 2021.

SARS-CoV-2, the virus that causes COVID-19 in humans, can infect multiple domestic and wild animal species (1 – 7). Thus, the possibility exists for the emergence of new animal reservoirs of SARS-CoV-2, each with unique potential to maintain, disseminate, and drive novel evolution of this virus. Of particular concern are wildlife species that are both abundant and live in close association with human populations (5).

No, it’s not forbidden to innovate, quite the opposite, but it’s always risky to do something different from what people are used to. Risk is the middle name of the bold, the builders of the future. Those who constantly face resistance from skeptics. Those who fail eight times and get up nine.

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Fernando Pessoa’s “First you find it strange. Then you can’t get enough of it.” contained intolerable toxicity levels for Salazar’s Estado Novo (Portugal). When the level of difference increases, censorship follows. You can’t censor censorship (or can you?) when, deep down, it’s a matter of fear of difference. Yes, it’s fear! Fear of accepting/facing the unknown. Fear of change.

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A new discovery explains what determines the number and position of genetic exchanges that occur in sex cells, such as pollen and eggs in plants, or sperm and eggs in humans.

When sex cells are produced by a special cell division called meiosis, chromosomes exchange large segments of DNA. This ensures that each new cell has a unique genetic makeup and explains why, with the exception of identical twins, no two siblings are ever completely genetically alike. These exchanges of DNA, or crossovers, are essential for generating genetic diversity, the driving force for evolution, and their frequency and position along chromosomes are tightly controlled.

Co-first author of the study Dr. Chris Morgan explains the significance of this phenomenon: “Crossover positioning has important implications for evolution, fertility and selective breeding. By understanding the mechanisms that drive crossover positioning we are more likely to be able to uncover methods to modify crossover positioning to improve current plant and animal breeding technologies.”

“It’s an extraordinary paper with some extraordinary claims,” says Gray Camp, a developmental biologist at the University of Basel in Switzerland, whose lab last year reported² growing brain organoids that contained a gene common to Neanderthals and humans. The latest work takes the research further by looking at gene variants that humans lost in evolution. But Camp remains sceptical about the implications of the results, and says the work opens more questions that will require investigation.

Humans are more closely related to Neanderthals and Denisovans than to any living primate, and some 40% of the Neanderthal genome can still be found spread throughout living humans. But researchers have limited means to study these ancient species’ brains — soft tissue is not well preserved, and most studies rely on inspecting the size and shape of fossilized skulls. Knowing how the species’ genes differ from humans’ is important because it helps researchers to understand what makes humans unique — especially in our brains.

The researchers, led by Alysson Muotri, a neuroscientist at the University of California, San Diego, used the genome-editing technique CRISPR–Cas9 to introduce the Neanderthal and Denisovan form of a gene called NOVA1 into human pluripotent stem cells, which can develop into any cell type. They cultured these to form organoids, clumps of brain-like tissue, up to 5 millimetres across, alongside normal human brain organoids for comparison.

In March 2017, Read and his Penn State colleague David Kennedy published a paper in the Proceedings of the Royal Society B in which they outlined several strategies that vaccine developers could use to ensure that future vaccines don’t get punked by evolutionary forces. One overarching recommendation is that vaccines should induce immune responses against multiple targets. A number of successful, seemingly evolution-proof vaccines already work this way: After people get inoculated with a tetanus shot, for example, their blood contains 100 types of unique antibodies, all of which fight the bacteria in different ways. In such a situation, it becomes much harder for a pathogen to accumulate all the changes needed to survive. It also helps if vaccines target all the known subpopulations of a particular pathogen, not just the most common or dangerous ones. Richard Malley and other researchers at Boston Children’s Hospital are, for instance, trying to develop a universal pneumococcal vaccine that is not serotype-specific.

Vaccines should also bar pathogens from replicating and transmitting inside inoculated hosts. One of the reasons that vaccine resistance is less of a problem than antibiotic resistance, Read and Kennedy posit, is that antibiotics tend to be given after an infection has already taken hold — when the pathogen population inside the host is already large and genetically diverse and might include mutants that can resist the drug’s effects. Most vaccines, on the other hand, are administered before infection and limit replication, which minimizes evolutionary opportunities.

But the most crucial need right now is for vaccine scientists to recognize the relevance of evolutionary biology to their field. Last month, when more than 1000 vaccine scientists gathered in Washington, D.C., at the World Vaccine Congress, the issue of vaccine-induced evolution was not the focus of any scientific sessions. Part of the problem, Read says, is that researchers are afraid: They’re nervous to talk about and call attention to potential evolutionary effects because they fear that doing so might fuel more fear and distrust of vaccines by the public — even though the goal is, of course, to ensure long-term vaccine success. Still, he and Kennedy feel researchers are starting to recognize the need to include evolution in the conversation. “I think the scientific community is becoming increasingly aware that vaccine resistance is a real risk,” Kennedy said.

The super app, synonymous with popular mobile apps like WeChat, Grab, GoTo and Paytm, has enjoyed noteworthy success in Asian countries, but is relatively absent in other markets. CNBC’s Nessa Anwar, joined by Arjun Kharpal, explains the strategies and evolution behind the world’s biggest super apps.

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