Humans reach southern South America

DNA from 139 Indigenous groups reveal that humans reached southern South America by 14,500 years ago.

A new genetic analysis reveals that humans crossing from Asia along the Bering Land Bridge during the last ice age underwent three major population splits as they traveled through the Americas. This journey has been identified as the longest human migration out of Africa. Eventually, a group settled in the southern part of South America some 14,500 years ago.

An international team of scientists analyzed 1,537 genomes of people from 139 different ethnic groups to identify genetic characteristics of the earliest Americans.

The GenomeAsia 100K consortium collected the genetic material, including some from Asian populations whose ancestors made early migrations into the Americas. The scientists were able to identify the genetic background of indigenous people throughout the Americas. They pinpointed three key time periods when the long-distance travelers split up.

The first population split occurred between 26,800 and 19,300 years ago during the Last Glacial Maximum. This was when Indigenous Americans split from North Eurasian people. These dates are consistent with a Native American presence at White Sands in New Mexico, as evidenced by ancient footprints and vehicle drag marks dated to 23,000 to 21,000 years ago.

The next major population split happened between 17,500 and 14,600 years ago. The indigenous population in North America split, and some made their way south. This Mesoamerican group then split rapidly into four native genetic lineages around 13,900 years ago. These groups were ancestral Pueblo peoples in the southwest US, as well as Amazonians, Andeans and Patagonians in South America.

This estimation actually fits well with the archaeological records, which indicate that people were living in the furthest southern reaches of the South American continent by about 14,500 years ago.

As people made their way into the new land tens of thousands of years ago, they experienced a reduction in their genetic diversity. First it was because of geographic barriers. Later, the populations were decimated after the arrival of European colonists.

One key loss was in the variation in human leukocyte antigen (HLA) genes. A high diversity of HLA genes is important for immune system health. In regions such as Southeast Asia with a high number of disease-causing organisms, previous studies found a high diversity of HLA genes. But in the Indigenous South American genomes, there was significantly lower diversity in the HLA genes. This may have led to these people being more vulnerable to novel pathogens.

One of the researchers’ aims is to emphasize the special medical needs of contemporary Indigenous peoples. Some have gene variants associated with problems like adverse drug reactions.

 

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What Was the Earth Like?

We’ve examined some of the creatures that existed before the dinosaurs, but what was the Earth like way back then?

From 354 to 290 million years ago was the Carboniferous Period. Hot and humid conditions covered the northern landmass, while the southern lands were much colder. Large club mosses, tree ferns, and horsetails grew in swamps and estuaries, along with seed-bearing plants. Some plants were up to 100 feet tall.

The insect population was quite varied, with millipedes, dragonflies, and other bugs. Some flying insects had wingspans up to two feet wide! Around the middle of the period, reptiles evolved as the first land-dwelling animals, and sharks and bony fishes replaced the jawless agnathans and armored placodems in the seas. Starfish, gastropods, sea urchins, and other marine invertebrates flourished on the reefs.

Approximately 350 million years ago, coal forests began to form in wetlands at the edges of continents. The submerged plant matter did not decompose completely and ended up being buried. This eventually transformed into coal.

The early reptiles had similar skeletal features to those of amphibians, but there were differences in their skulls and vertebrae that signified their relationship to later reptiles such as turtles and dinosaurs.

Then came glaciations, a decrease in sea levels, and the formation of Pangaea, when the continents joined together. A minor extinction event of both marine and land life happened at the end of the period due to climate change. This is known as the Carboniferous rainforest collapse.

 

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Pre-Dinosaurs Prehistoric Animals

Dinosaurs wandered the Earth for millions of years, searching for food and defending their territories. They roamed the world from 252- to 66-million years ago. But what about before the dinosaurs? It turns out that Earth’s creatures were highly diverse, as well as enormous. Let’s take a look at 9 massive prehistoric animals that lived before dinosaurs.

Scutosaurus

This “shield lizard” arose around 298 million years ago. It was among the largest reptiles at the time. It features a 20-inch spiked skull and an armor-plated body that could grow over 10 feet. It was hulking and intimidating, but research suggests it was a slow, heavy-footed herbivore that walked for miles through its desert habitat looking vegetation. It was vulnerable to predators, like the Gorgonopsids.

Gorgonopsids

Named after the Greek Gorgon, this group of saber-toothed mammals had narrow skulls and elongated teeth, which they used to slash and stab. They were vicious hunters. They would take chunks out of their target and retreat until it was so weak, they couldn’t avoid the final, killing bite. Gorgonopsids may have begun relatively small but evolved to bear sized. They became apex predators in area of Tanzania, Zambia, and Malawi.

Pterygotus

This sea scorpion was an enormous predatory aquatic arthropod. It reached almost 6 feet and lived on Earth’s oceans, hunting other creatures, such as fish. I had no stinger, but had behemoth claws and would wait in ambush for its prey, when it would grab and puncture them with its pincers. The first Pterygotus fossils were found in early Devonian deposits in Scotland and Western England. Some of its features are recognizable in modern sea creatures, but sea scorpions no longer exist.

Dimetrodon Angelensis

Although this creature look reptilian, it’s not related to dinosaurs. It’s more closely related to mammals, though it’s not a mammal. It belongs to a group of advanced carnivores. Its most prominent feature is a sizeable spine sail, supported by spines extending from its vertebrate. I walked on 4 legs, had a curved skull, and large teeth. Its fossils have been found in southwestern US, in Oklahoma and Texas.

Jaekelopterus

This was another giant scorpion living during the Devonian Period 390 million years ago. It was the biggest arthropod ever, growing over eight feet long. This scorpion developed in freshwater systems like rivers, where it was an apex predator. Research suggests it chased its prey in lagoons and estuaries with much maneuverability and agility.

Arthropleura

Gigantic millipede arthropods roamed the forests of North America and Europe 345 million years ago. They were the largest land invertebrates ever and wouldn’t have had many predators. They grew over 7 feet and could stand upright and spray acid at any threat. These millipedes were some of the first plant-eaters. Their powerful jaws were used to break down tough vegetative matter.

Meganeura

This was the largest flying insect and resembled a modern dragonfly. It inhabited the forests alongside the Arthropleura and mainly consumed other insects. Its wingspan reached 25.6 inches. Its larvae was at least 12 inches long. It spent much of its time in the air, looking for food. Scientists first discovered it fossil in France in 1880.

Titanichthys

This was a giant armored fish from the late Devonian Period. It lived I shallow seas. Scientists believe it was the first large vertebrate filter feeder, using its mouth to inhale small fish. It could reach a length of 16 feet, had a huge mouth, and blunt teeth.

Aegirocassis

This creature lived 480 million years ago. It was the largest animal to exist at the time and the earliest giant filter feeder. This arthropod most closely resembled a prawn. It reached 7 feet long and had swimming flaps and a filtering mesh that helped guide food into its mouth. It lived in a shallow sea that covered what is today the Sahara Desert.

 

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Lost Mayan City Found

Archaeologists were scanning through jungle terrain when they stumbled on what could have been an important Maya location. They discovered a mysterious structure built under a ball court, which was popular in large Maya cities. Other discoveries included pyramids and evidence of drainage systems. Most of the findings have been calculated to have been used between 200 AD to 1000 AD.

The height of the Maya kingdom stretched from 250 to 900 AD. The rise of the Maya Ballgame, sometimes called pitz, saw the building of ball court structures in the center of major cities. These courts were a symbol of wealth and power, hence their prime placement.

Not only was one of these courts found in a Mexican jungle, but also uncovered was a cryptic construction under the court, leading to questions about the structure’s use.

Archaeologists were exploring light detection and ranging (lidar) readings in the Mexican state Campeche when they noticed unique shapes in a roughly 54-square-mile section of the Balam Ku Biosphere Reserve. The shapes were actually modest-sized settlements with a few larger buildings. There were practically no standing walls, and no key architectural decoration.

The impression was that the Maya culture of this region was less elaborate than those in other regions.

While excavating the ball court, the team discovered parts of a building covered with remnants of painted stucco located beneath. Because ball courts were typically built at the center of cities, speculation is that the building had some prominence as well. But speculation is all they have for now. It is estimated that the building dates somewhere between 200 and 600 AD.

Other major finds include a main plaza surrounded with elongated structures. The plaza features a pyramid and a drainage channel. The team believes the site was occupied from 600 to 1000 AD.

Another discovery is a 52-foot-tall pyramid near a water reservoir, complete with the remains of offerings atop the structure. The offering remnants included ceramic fragments, a flint point, and an animal leg, likely of an armadillo or large rodent. The scientists believe this find dates from 1250 to 1524 AD and that it shows the presence of humans in the area even after the height of the Maya civilization and before the arrival of the Spanish.

 

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What Existed Before The Big Bang

Our universe began with The Big Bang. But what existed before the Big Bang?

From the University of Texas at Austin, researchers propose that dark matter might have been created during a brief, explosive period of expansion called “Cosmic Inflation,” which occurred just before the Big Bang. The universe, at that point, would have consisted of mostly dark matter, completely undetectable to our eyes.

Scientists believe that dark matter makes up roughly 85% of all matter. This study suggests that the substance existed before the event that many consider the beginning of time.

The model for the study assumes that dark matter is successfully produced during inflation. In most models, anything that is created during inflation is thinned away by the expansion of the universe until there is essentially nothing left.

The research introduces a mechanism called WIFI (Warm Inflation Freeze-In), which suggests that dark matter could have been generated during the universe’s earliest moments through rare interactions within an incredibly hot and energetic environment.

Cosmologists understand the universe’s beginning was more complex than a simple explosive moment. Before the Big Bang, matter and energy were compressed into an incredibly dense state that physicists struggle to describe. A fraction of a second of rapid expansion preceded the Big Bang, setting the stage for everything that would follow.

In this new model, the quantum field driving inflation loses some energy to radiation, which then produces dark matter particles through a process called ‘freeze-in’. According to this research, all the dark matter that exists today could have been created during that brief inflationary period.

The study focused on the production of dark matter, but WIFI suggests the production of other particles that could play a role in the early universe’s evolution.

Although currently unconfirmable through direct observation, the theory opens exciting new avenues for exploring the universe’s fundamental building blocks. The researchers are optimistic that upcoming experiments studying the Cosmic Microwave Background and large sale universal structures could provide validation.

 

https://www.msn.com/en-us/news/technology/scientists-may-finally-know-what-existed-before-the-big-bang/ar-AA1vY9Mf?ocid=hpmsn&cvid=51d4d625bcc24515f51422de711080a7&ei=66