Archive for the ‘evolution’ category: Page 94
Apr 6, 2021
Humans Were Apex Predators for Two Million Years – Our Stone Age Ancestors Mostly Ate Meat
Posted by Quinn Sena in categories: evolution, existential risks, food, genetics, military
Researchers at Tel Aviv University were able to reconstruct the nutrition of stone age humans.
In a paper published in the Yearbook of the American Physical Anthropology Association, Dr. Miki Ben-Dor and Prof. Ran Barkai of the Jacob M. Alkov Department of Archaeology at Tel Aviv University, together with Raphael Sirtoli of Portugal, show that humans were an apex predator for about two million years. Only the extinction of larger animals (megafauna) in various parts of the world, and the decline of animal food sources toward the end of the stone age, led humans to gradually increase the vegetable element in their nutrition, until finally they had no choice but to domesticate both plants and animals — and became farmers.
“So far, attempts to reconstruct the diet of stone-age humans were mostly based on comparisons to 20th century hunter-gatherer societies,” explains Dr. Ben-Dor. “This comparison is futile, however, because two million years ago hunter-gatherer societies could hunt and consume elephants and other large animals — while today’s hunter gatherers do not have access to such bounty. The entire ecosystem has changed, and conditions cannot be compared. We decided to use other methods to reconstruct the diet of stone-age humans: to examine the memory preserved in our own bodies, our metabolism, genetics, and physical build. Human behavior changes rapidly, but evolution is slow. The body remembers.”
April 6 — 7, 2021, 9:00am — 5:00pm EST
MAKING IN SPACE
FROM MINING TO MANUFACTURING
As humanity expands into space and unlocks the incalculable abundance of the CisLunar Econosphere, Orbital Manufacturing is a necessary first step.
Here on Earth, settlements emerged around concentrations of natural resources: rivers, forests, ores, harbors, fertile fields. Roads then developed between the resources and settlements, and towns grew. Resource extraction (mining) and resource optimization (manufacturing) evolved. Eventually, specialization led to local, regional, and national competitive advantages. With growth speeding the process, communities and people prospered!
Mar 31, 2021
Bones evolved to act like batteries, 400-million-year-old fish suggest
Posted by Quinn Sena in categories: education, evolution
The earliest bones, however, were very different from human skeletons today. In the prehistoric past, bone was more like concrete, growing on the exterior of fish to provide a protective shell. But according to a new study in the journal Science Advances, the first bones with living cells—like those found in humans—evolved about 400 million years ago and acted as skeletal batteries: They supplied prehistoric fish with minerals needed to travel over greater distances.
The fossilized creatures in the analysis are known as osteostracans. “I affectionately call them beetle mermaids,” says Yara Haridy, a doctoral candidate at the Berlin Museum of Nature and lead author of the study. These fish had a hard, armor-encased front end and a flexible tail growing out the back. They had no jaws, and their bone tissue encased their bodies. These kinds of fish are critical to understanding the origins of the hard parts that shaped vertebrate evolution.
Mar 29, 2021
Evolution drives autism and other conditions to occur much more frequently in boys
Posted by Jason Blain in categories: biotech/medical, evolution, genetics, health, neuroscience
In autism, male-female imbalance is especially pronounced. Boys are as much as four times more likely to have some form of autism and are also more likely to have severe symptoms.
HAMILTON, ON, March 3, 2021 — Evolutionary forces drive a glaring gender imbalance in the occurrence of many health conditions, including autism, a team of genetics researchers has concluded.
The human genome has evolved to favour the inheritance of very different characteristics in males and females, which in turn makes men more vulnerable to a host of physical and mental health conditions, say the researchers responsible for a new paper published in the Journal of Molecular Evolution.
Mar 27, 2021
First Look Over the Event Horizon of Singularity: Your Future Life as a Cyberhuman
Posted by Alex Vikoulov in categories: alien life, economics, evolution, internet, nanotechnology, singularity
The lives of infomorphs (or ‘cyberhumans’) who have no permanent bodies but possess near-perfect information-handling abilities, will be dramatically different from ours. Infomorphs will achieve the ultimate morphological freedom. Any infomorph will be able to have multiple cybernetic bodies which can be assembled and dissembled at will by nanobots in the physical world if deemed necessary, otherwise most time will be spent in the multitude of virtual bodies in virtual enviro… See More.
“I am not a thing — a noun. I seem to be a verb, an evolutionary process — an integral function of the Universe.” — Buckminster Fuller
The term ‘Infomorph’ was first introduced in “The Silicon Man” by Charles Platt in 1991 and later popularized by Alexander Chislenko in his paper “Networking in the Mind Age”: “The growing reliance of system connections on functional, rather than physical, proximity of their elements will dramatically transform the notions of personhood and identity and create a new community of distributed ‘infomorphs’ — advanced informational entities — that will bring the ongoing process of liberation of functional structures from material dependence to its logical conclusions. The infomorph society will be built on new organizational principles and will represent a blend of a superliquid economy, cyberspace anarchy and advanced consciousness.”
Mar 26, 2021
Three-dimensional, multifunctional neural interfaces for cortical spheroids and engineered assembloids
Posted by Saúl Morales Rodriguéz in categories: biotech/medical, chemistry, evolution, neuroscience
Three-dimensional (3D), submillimeter-scale constructs of neural cells, known as cortical spheroids, are of rapidly growing importance in biological research because these systems reproduce complex features of the brain in vitro. Despite their great potential for studies of neurodevelopment and neurological disease modeling, 3D living objects cannot be studied easily using conventional approaches to neuromodulation, sensing, and manipulation. Here, we introduce classes of microfabricated 3D frameworks as compliant, multifunctional neural interfaces to spheroids and to assembloids. Electrical, optical, chemical, and thermal interfaces to cortical spheroids demonstrate some of the capabilities. Complex architectures and high-resolution features highlight the design versatility. Detailed studies of the spreading of coordinated bursting events across the surface of an isolated cortical spheroid and of the cascade of processes associated with formation and regrowth of bridging tissues across a pair of such spheroids represent two of the many opportunities in basic neuroscience research enabled by these platforms.
Progress in elucidating the development of the human brain increasingly relies on the use of biosystems produced by three-dimensional (3D) neural cultures, in the form of cortical spheroids, organoids, and assembloids (1–3). Precisely monitoring the physiological properties of these and other types of 3D biosystems, especially their electrophysiological behaviors, promises to enhance our understanding of the interactions associated with development of the nervous system, as well as the evolution and origins of aberrant behaviors and disease states (4–8). Conventional multielectrode array (MEA) technologies exist only in rigid, planar, and 2D formats, thereby limiting their functional interfaces to small areas of 3D cultures, typically confined to regions near the bottom contacting surfaces.
Mar 18, 2021
New Technique Reveals Genes Underlying Human Evolution
Posted by Genevieve Klien in categories: biotech/medical, evolution, genetics
Summary: A new technique which involves fusing human and chimpanzee skin cells that have been modified to act like stem cells, allowed researchers to identify two novel genetic differences between humans and chimps.
Source: Stanford University.
One of the best ways to study human evolution is by comparing us with nonhuman species that, evolutionarily speaking, are closely related to us. That closeness can help scientists narrow down precisely what makes us human, but that scope is so narrow it can also be extremely hard to define. To address this complication, researchers from Stanford University have developed a new technique for comparing genetic differences.
Mar 14, 2021
How Far Should Humans Go to Help Species Adapt?
Posted by Genevieve Klien in categories: climatology, evolution, sustainability
A project to teach threatened marsupials to avoid feral cats is among a host of “assisted evolution” efforts to help animals in the face of climate change.
Mar 12, 2021
Photosynthesis tunes quantum-mechanical mixing of electronic and vibrational states to steer exciton energy transfer
Posted by Saúl Morales Rodriguéz in categories: biological, evolution, quantum physics
Photosynthetic light-harvesting antennae transfer energy toward reaction centers with high efficiency, but in high light or oxidative environments, the antennae divert energy to protect the photosynthetic apparatus. For a decade, quantum effects driven by vibronic coupling, where electronic and vibrational states couple, have been suggested to explain the energy transfer efficiency, but questions remain whether quantum effects are merely consequences of molecular systems. Here, we show evidence that biology tunes interpigment vibronic coupling, indicating that the quantum mechanism is operative in the efficient transfer regime and exploited by evolution for photoprotection. Specifically, the Fenna–Matthews–Olson complex uses redox-active cysteine residues to tune the resonance between its excitons and a pigment vibration to steer excess excitation toward a quenching site.
Photosynthetic species evolved to protect their light-harvesting apparatus from photoxidative damage driven by intracellular redox conditions or environmental conditions. The Fenna–Matthews–Olson (FMO) pigment–protein complex from green sulfur bacteria exhibits redox-dependent quenching behavior partially due to two internal cysteine residues. Here, we show evidence that a photosynthetic complex exploits the quantum mechanics of vibronic mixing to activate an oxidative photoprotective mechanism. We use two-dimensional electronic spectroscopy (2DES) to capture energy transfer dynamics in wild-type and cysteine-deficient FMO mutant proteins under both reducing and oxidizing conditions. Under reducing conditions, we find equal energy transfer through the exciton 4–1 and 4–2–1 pathways because the exciton 4–1 energy gap is vibronically coupled with a bacteriochlorophyll-a vibrational mode.