•   
  •   

Health & Fitness Were the first humans superpredators?

19:25  19 april  2021
19:25  19 april  2021 Source:   livescience.com

Ultrasound treatment 'jump-started' the brains of 2 people in coma-like state

  Ultrasound treatment 'jump-started' the brains of 2 people in coma-like state The two patients who received the treatment showed significant progress over just days.Both patients had severe brain injuries and had shown only limited signs of consciousness for more than a year. But after receiving the treatment — which involved ultrasound to "excite" cells in a brain region called the thalamus — the patients showed sudden improvements in their condition, according to the study, published Jan. 15 in the journal Brain Stimulation. For example, after treatment, one patient could move their head to indicate "yes" or "no" in response to certain questions.

The first humans were mega-carnivores who took down prey with savvy hunting skills, a controversial new study suggests. In a new research paper, scientists argue that humans and their close relatives were expert hunters from early on, starting at least 2 million years ago. Not only that, but the earliest human species were superpredators , taking down animals twice as large as any terrestrial creature alive today, said Miki Ben-Dor and Ran Barkai, researchers at Tel Aviv University in Israel, and Raphael Sirtoli, a doctoral student at the University of Minho in Portugal.

Humans are predators so unique and extreme that they are " superpredators " in a class apart from other carnivores, a group of Canadian scientists says. "The magnitude of this difference … was our first surprise," said Darimont, the Hakai-Raincoast professor of geography at the University of Victoria and science director for the Raincoast Conservation Foundation, at a media teleconference organized by the journal Science.

The first humans were mega-carnivores who took down prey with savvy hunting skills, a controversial new study suggests.

a group of sheep that are standing in the snow: An illustration of the steppe mammoths that preceded the woolly mammoth, based on the genetic knowledge from the Adycha mammoth. © Provided by Live Science An illustration of the steppe mammoths that preceded the woolly mammoth, based on the genetic knowledge from the Adycha mammoth.

In a new research paper, scientists argue that humans and their close relatives were expert hunters from early on, starting at least 2 million years ago. Not only that, but the earliest human species were superpredators, taking down animals twice as large as any terrestrial creature alive today, said Miki Ben-Dor and Ran Barkai, researchers at Tel Aviv University in Israel, and Raphael Sirtoli, a doctoral student at the University of Minho in Portugal.

Flesh-eating infection spreading fast through Australia - urgent health alert issued

  Flesh-eating infection spreading fast through Australia - urgent health alert issued A FLESH-EATING disease is spreading through Australia with health authorities forced to issue an immediate health alert.Researchers are still trying to discover how the Buruli ulcer spreads to humans.

This latest piece of news or article about Were the first humans superpredators ? was originally reported by www.livescience.com. Let's have a look at what ShowbizHO! According to the reports by www.livescience.com, “ Were the first humans superpredators ?.” A new hypothesis suggests that humans were hypercarnivores more than 2 million years ago, specializing in taking down the largest prey.

Early human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early

"So far, attempts to reconstruct the diet of Stone Age humans were mostly based on comparisons to 20th-century hunter-gatherer societies," Ben-Dor said in a statement. "This comparison is futile, however, because 2 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."

Related: 15 of the largest animals of their kind on Earth

A limited record

Fossil evidence from the earliest human ancestors is scarce. But based on archaeological evidence, Ben-Dor told Live Science, it's clear that Homo sapiens and their close relatives ate "anything edible." But how much of their diets comprised plants versus animals is the sticking point. (Another sticking point: When did humans start hunting meat themselves, rather than scavenging it?) Many animals considered omnivorous actually have diets weighted one way or another. Chimpanzees, for example, are technically omnivores, but meat makes up only about 6% of their diets, according to the Jane Goodall Institute of Canada. Dogs and wolves eat mostly meat but sometimes gorge on grains, leading to a debate over whether they should be classified as omnivores or carnivores.

Shrimps producing less sperm in polluted waters ‘is warning to humans’

  Shrimps producing less sperm in polluted waters ‘is warning to humans’ Experts said the findings over the aquatic creatures should be treated as a ‘canary in the cage’ over the effect on other life, including our species.Researchers from the University of Portsmouth also found that there were six times less of the sea creatures living in the study area on the south coast of England, compared with cleaner waters.

Were the first humans superpredators ? By Stephanie Pappas. A new hypothesis suggests that humans were hypercarnivores more than 2 million years ago, specializing in taking down the largest prey. NASA's Mars helicopter Ingenuity takes off on historic 1st powered flight on another world. By Mike Wall.

So the first humans were African. Every other ethnic group is pretty much a mutation. Light skin is recessive. Dark skin was the template, the norm, skin color. I am not saying that people with lighter skinned are lesser, I’m simply saying that the first humans were dark skinned people. Genetically, today’s races are all equally far descended from the “ first ” humans . I hope you understand that humans evolved gradually from apelike ancestors, and that this evolution was gradual and over a long, long period of time. So there’s no real way to decide who were the “ first ” humans .

The ancient human species Homo habilis was eating meat at least 2.6 million years ago, Ben-Dor said. Another early human species, Homo erectus, seems to have been a particularly enthusiastic meat eater by 1.8 million years ago; its teeth and gut shrank compared with earlier ancestors — adaptations for digesting meat instead of plants — and it used stone tools capable of butchering meat.

Ben-Dor and Barkai argue in their paper, published March 5 in the American Journal of Physical Anthropology, that meat wasn't just a bonus for these human species and the first Homo sapiens. Instead, the authors believe large animals weighing over 2,200 lbs. (1,000 kilograms) — such as elephants, hippopotamuses and rhinoceroses — made up most of humans' diets. These huge herbivores were much more common — and much larger — in the Pleistocene epoch, starting about 2.5 million years ago, than they are today. .

First 'Homo' species left Africa with ape-like brains

  First 'Homo' species left Africa with ape-like brains Early members of the genus Homo didn't have advanced brains.This means that the unique brain of modern humans (Homo) developed more than 1 million years after the Homo genus arose, and after the first Homo erectus migrated out of Africa, according to the study, published online Thursday (April 7) in the journal Science.

"There are predators, and then there is the superpredator , which is us," says Zanette. "Research has shown that globally humans kill large carnivores at nine times the rate at which they are naturally killed. We also kill middle-of-the-food-chain animals at four times the rate they are killed by their large This effect can obviously be observed in more than just California cougars. Virtually every ecosystem in the world is flooded with superpredators (that's us humans , remember) at this point. Large carnivores are increasingly forced to live in human -dominated landscapes, and they evidently live in terror of us.

This is mostly false. It was Hillary Clinton, then the first lady, who used the word " superpredator " to advocate for the 1994 crime bill that Biden co-wrote more than 30 years ago. Biden did warn of "predators" in a floor speech in support of his bill, however. During his first year in office, his bill remained 0. The information doesn't include his returns from 2018 and 2019. According to The Times, Trump had paid no income taxes at all in 10 of the 15 years before 2016, because he reported losing much more money than he made during that time.

"Elephants 500,000 years ago could weigh 12 tons, compared to 4 to 6 tons today," Ben-Dor said.

These animals would have been walking buffets of fatty meat, well suited to feeding humans' energy-hungry brains, according to the researchers. The authors argued in another recent paper that hunting large prey might have been what drove human brain evolution.

This idea is controversial, however, and researchers do not agree on how useful a huge influx of meat would have been to hunter-gatherers in the days before refrigeration, nor on how skilled ancient humans would have been at taking down prey that other apex carnivores, like lions, struggle to defeat.

"There are some archaeologists who'd say, 'Yeah, they hunted elephant once in a while, but that was like a once-in-a-lifetime hunt; that's the thing grandparents would tell their kids stories about,'" said John Hawks, a paleoanthropologist at the University of Wisconsin-Madison who was not involved in the research. "There are others who said 'No, meat from an elephant can last a long time. … Without storage, it's less than you think, but it was a regular part of their subsistence, and it was important to them.'"

J&J coronavirus vaccine can resume in US, CDC advisory panel recommends

  J&J coronavirus vaccine can resume in US, CDC advisory panel recommends A CDC advisory panel voted to recommend that the U.S. resume administering the Johnson & Johnson vaccine for people 18 years of age and older. This comes after an 11-day pause in administering the vaccine prompted by reports of extremely rare, but severe, blood clots that developed post-vaccination in a handful of people. © Provided by Live Science A vaccine syringe in front of a Johnson and Johnson logo.

A fatty diet?

Eating large, fatty animals would have been a benefit to the earliest humans, Ben-Dor and his colleagues wrote in their paper, because bringing down that many calories in one hunting trip — rather than multiple attempts to stalk smaller prey —— would have freed up time for other pursuits, such as toolmaking and child-rearing. The researchers argue that humans show adaptations for this high-fat, meat-heavy life, ranging from particularly acidic stomach juices (also found in other animals with meat-heavy diets) to small jaws (because meat eaters have to chew less than herbivores that must break down large amounts of fibrous vegetation for the same calories).

Archaeologically speaking, it's difficult to categorize humans and their relatives as one level of predator prior to about 50,000 years ago, Ben-Dor said. That's because the only reliable biochemical way to distinguish whether an animal is a top predator or fits lower on the food chain is a method called stable nitrogen isotope analysis, which requires testing collagen for molecules introduced into the body via the diet. Consumers contain a few percentage points more of the isotope nitrogen-15 than what is found in either the plants or animals they eat, making it possible to determine their level in the food web, also known as their trophic level.

What is Darwin's Theory of Evolution?

  What is Darwin's Theory of Evolution? Charles Darwin's theory of evolution and natural selection isn't an idea with holes. It's one of the most solid theories in science. But what exactly is it?Darwin chose the term "natural selection" to be in contrast with "artificial selection," in which animal breeders select for particular traits that they deem desirable, according to National Geographic. In natural selection, it's the natural environment, rather than a human being, that does the selecting.

Collagen, the connective tissue found in abundance in bones, doesn't preserve well prior to 50,000 years ago, though. The samples from that era hail from Europe, where cooler temperatures allow for better preservation, and they do indicate that humans were eating large mammals. However, 50,000 years ago in Europe is a far cry from 300,000 years ago in Africa, when and where the first H. sapiens arose, Hawks said.

Adding to the difficulties in determining ancient humans' diets, it's hard to determine precise dates for archaeological materials from the crucial time periods in the middle Pleistocene, when human diets were evolving, Hawks added.

"This is a time frame when our ability to determine the age of things relies on methods that have about a 100,000-year, sometimes 50,000-year, span of uncertainty about them. … That's a lot of error," Hawks told Live Science. And there are far fewer sites to make inferences from that are older than 100,000 years compared with those younger than 100,000 years, he said.

Despite the limited evidence from humanity's early evolution, the researchers said there is more work to be done to show whether these human ancestors truly were specialized carnivores. This might include more work on the abundance of animals of different sizes throughout the Pleistocene, explorations of genetic changes over time that would have altered humans' ability to digest different foods and comparisons of trends in prey size over time.

"I feel that we have only scratched the surface, exploring paleobiology's potential to discover our past and present adaptation to consuming meat and animal fat," Ben-Dor said.

Originally published on Live Science.

Gut bacteria may 'talk' to the brain, mouse study suggests .
Research suggests that gut bacteria may also influence human brain activity and behavior.Specifically, researchers wanted to find out how gut bacteria influence the activity of brain networks involved in mouse social behavior. Normally, when a mouse encounters a mouse it's never met, the two rodents will sniff at each other's whiskers and clamber over each other, much like how two dogs might greet each other at a dog park. However, germ-free mice, which lack gut bacteria, actively avoid social interactions with other mice and instead remain strangely aloof.

usr: 0
This is interesting!