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Archive for the ‘evolution’ category: Page 3

Dec 26, 2023

Social learning: Simulation model shows how groups can keep important information within and across generations

Posted by in category: evolution

One of the most actively debated questions about human and nonhuman culture is this: Under what circumstances might we expect culture, in particular the ability to learn from one another, to be favored by natural selection?

Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have developed a simulation model of the evolution of . They showed that the interplay between learning, memory and forgetting broadens the conditions under which we expect to see social learning to evolve.

Social learning is typically thought to be most beneficial when the environments in which live change quite slowly—they can safely learn tried and tested information from one another and it does not go out of date quickly. Innovating brand-new information, on the other hand, is thought to be useful in dynamic and rapidly changing environments.

Dec 25, 2023

Ancient Neanderthal DNA Shaping Modern Morning Habits

Posted by in categories: biotech/medical, evolution, genetics

A new paper in the journal Genome Biology and Evolution, published by Oxford University Press, finds that genetic material from Neanderthal ancestors may have contributed to the propensity of some people today to be “early risers,” the sort of people who are more comfortable getting up and going to bed earlier.

Human Evolution and Genetic Adaptation

All anatomically modern humans trace their origin to Africa around 300 thousand years ago, where environmental factors shaped many of their biological features. Approximately seventy thousand years ago, the ancestors of modern Eurasian humans began to migrate out to Eurasia, where they encountered diverse new environments, including higher latitudes with greater seasonal variation in daylight and temperature.

Dec 25, 2023

Psychedelic concentrations of nitrous oxide reduce functional differentiation in frontoparietal and somatomotor cortical networks

Posted by in categories: biotech/medical, evolution, neuroscience

Cortical gradient mapping stands as an innovative analytical tool for exploring the brain’s functional-spatial organization along a continuous spectrum28,29,30, distinguishing it from conventional techniques reliant on discrete boundaries, e.g., functional parcellation in neuroimaging. As an intuitive metaphor, consider defining a geographic region by its boundary coordinates, which is akin to functional parcellation, versus describing it by elevation slopes or changes in vegetation types across various topographical axes, which is similar to gradient mapping. These cortical gradients span a wide spectrum of functions and networks, ranging from perception and action to higher-order cognitive processes28. Notably, Gradient-1, known as the unimodal to transmodal gradient, enables the integration of sensory signals with non-sensory data, transforming them into abstract content. Gradient-2, the visual to somatomotor gradient, represents the specialization of different sensory modalities. Lastly, Gradient-3 spans functional distinctions ranging from regions typically deactivated during task performance (i.e., task-negative) to those activated in frontoparietal and attention networks (i.e., task-positive)31,32. Despite promising foundations, the potential of gradients as a framework for analyzing and conceptualizing non-ordinary states of consciousness induced by psychedelics remains ripe for exploration.

In addition to the brain’s functional geometry, dynamic processes continuously mold and reconfigure functional arrangements, leading to the evolution of brain activity patterns over time33,34. Recent empirical investigations have highlighted the intricate interplay between the spatial and temporal characteristics of brain activity, emphasizing that a comprehensive understanding necessitates the consideration of both aspects. Notably, transient fMRI co-activations33,35,36 spanning the entire cortex have been observed to propagate like waves, following the spatially defined cortical gradients37,38,39. Consequently, temporal dynamics are likely to be influenced by the underlying functional geometry. Exploring the co-variation between these spatial and temporal factors holds the potential to offer deeper insights into the neural underpinnings of psychedelic effects.

The objective of this study was to apply advanced cortical gradient mapping and co-activation pattern analysis to dissect the brain’s spatiotemporal reconfiguration during the psychedelic experience induced by nitrous oxide. Building upon previous research findings16,25, we tested the hypothesis that nitrous oxide could diminish functional differentiation within the human cortex, as evidenced by a contraction in functional geometry and a disruption in temporal dynamics. We reanalyzed a neuroimaging dataset of healthy human volunteers, who were assessed by fMRI before and during exposure to psychedelic concentrations of nitrous oxide (35%, in oxygen) and who completed a validated altered states of consciousness questionnaire40 before and after drug exposure. We quantified the changes of neural activity in cortical gradients and co-activations; we also performed correlation analyses to explore the relationship between subjective psychedelic experience and these brain measures. We demonstrate that nitrous oxide flattens the functional geometry of the cortex and disrupts related temporal dynamics, particularly within the frontoparietal and somatomotor networks, in association with the psychedelic experience.

Dec 24, 2023

Researchers develop effective method to genetically modify brain organoids

Posted by in categories: biotech/medical, evolution, genetics, neuroscience

Primates are among the most intelligent creatures with distinct cognitive abilities. Their brains are relatively large in relation to their body stature and have a complex structure. However, how the brain has developed over the course of evolution and which genes are responsible for the high cognitive abilities is still largely unclear. The better our understanding of the role of genes in brain development, the more likely it will be that we will be able to develop treatments for serious brain diseases.

Researchers are approaching these questions by knocking out or activating individual genes and thus drawing conclusions about their role in . To avoid as far as possible, brain organoids are used as an alternative. These three-dimensional cell structures, which are only a few millimeters in size, reflect different stages of brain development and can be genetically modified. However, such modifications are usually very complex, lengthy and costly.

Researchers at the German Primate Center (DPZ)—Leibniz Institute for Primate Research in Göttingen have now succeeded in genetically manipulating brain organoids quickly and effectively. The procedure requires only a few days instead of the usual several months and can be used for organoids of different primate species. The brain organoids thus enable of the function of genes at early stages of brain development in primates and help to better understand neurological diseases.

Dec 24, 2023

Brain Evolution Unlocked: Over 100 Genes That Make Us Uniquely Human

Posted by in categories: biotech/medical, evolution, neuroscience

The researchers found 139 genes that are common across the primate groups but highly divergent in their expression in human brains.

An international team led by researchers at the University of Toronto has uncovered over 100 genes that are common to primate brains but have undergone evolutionary divergence only in humans – and which could be a source of our unique cognitive ability.

The researchers, led by Associate Professor Jesse Gillis from the Donnelly Centre for Cellular and Biomolecular Research and the Department of Physiology at U of T’s Temerty Faculty of Medicine, found the genes are expressed differently in the brains of humans compared to four of our relatives – chimpanzees, gorillas, macaques, and marmosets.

Dec 24, 2023

New Fossil Analysis Has Just Re-Written The Human Evolution Timeline

Posted by in category: evolution

New dating analysis of existing human remains found worldwide has raised questions about some of our current histories of human evolution.

Dec 23, 2023

The First Stars and the Cosmic Dawn: A Journey to the Beginning of Time with Webb

Posted by in categories: alien life, chemistry, evolution, physics

Have you ever wondered what the universe looked like before the first stars were born? How did these stars form and how did they change the cosmos? These are some of the questions that the James Webb Space Telescope, or Webb for short, will try to answer. Webb is the most powerful and ambitious space telescope ever built, and it can observe the infrared light from the most distant and ancient objects in the universe, including the first stars. The first stars are extremely hard to find, because their light is very faint and redshifted by the expansion of the universe. But Webb has a huge mirror, a suite of advanced instruments, and a unique orbit that allows it to detect and study the first stars. By finding the first stars, Webb can learn a lot of information that can help us understand the early history and evolution of the universe, and test and refine the theoretical models and simulations of the first stars and their formation processes. Webb can also reveal new and unexpected phenomena and raise new questions about the first stars and their role in the universe. Webb is opening a new window to the cosmic dawn, where the first stars may shine. If you want to learn more about Webb and the first stars, check out this article1 from Universe Today. And don’t forget to like, share, and subscribe for more videos like this. Thanks for watching and see you next time. \
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Dec 21, 2023

Apes’ Long-Term Social Memory Mirrors Human Ability

Posted by in category: evolution

Researchers found that chimpanzees and bonobos can recognize former groupmates they haven’t seen for over 25 years, showing more attention to those they had positive relationships with.

This study, conducted with apes at various zoos and sanctuaries, used eye-tracking technology to measure apes’ responses to photographs of familiar and unfamiliar individuals.

The findings suggest that such enduring social memory in apes could have played a foundational role in the evolution of human culture and interpersonal relationships.

Dec 21, 2023

A new mathematical language for biological networks

Posted by in categories: biological, evolution, genetics, health, mathematics

A team of researchers around Berlin mathematics professor Michael Joswig is presenting a novel concept for the mathematical modeling of genetic interactions in biological systems. Collaborating with biologists from ETH Zurich and Carnegy Science (U.S.), the team has successfully identified master regulators within the context of an entire genetic network.

The research results provide a coherent theoretical framework for analyzing biological networks and have been published in the Proceedings of the National Academy of Sciences.

It is a longstanding goal of biologists to determine the key genes and species that have a decisive impact on evolution, ecology, and health. Researchers have now succeeded in identifying certain genes as master regulators in biological networks. These key regulators exert greater control within the system and steer essential cellular processes. Previous studies have mainly focused on pairwise interactions within the system, which can be strongly affected by genetic background or biological context.

Dec 19, 2023

Ancient Insect Mysteries Solved: 312-Million-Year-Old Fossil Sheds Light on Behavior and Evolution

Posted by in categories: biological, evolution

Prehistoric insects, with their delicate and soft bodies, are challenging to preserve as fossils. While wings are more commonly fossilized, the bodies of these insects are often fragmented or incomplete, posing difficulties for scientific study. Paleontologists often rely on trace fossils to learn about these ancient insects, which are almost exclusively found as traces on fossil plants.

“We have a great fossil plant record,” said Richard J. Knecht, a Ph.D. candidate in the Department of Organismic and Evolutionary Biology at Harvard. “Further back in time, it’s the trace fossils that tell us more about the evolution and behavior of insects than the body fossils because plants and the trace fossils on them preserve very well. And the trace, as opposed to a body, won’t move over time and is always found where it was made.”

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