37,000 Years of Disease

With ancient DNA, scientists have mapped 37,000 years of disease across Europe and Asia.

More than 200 modern diseases are zoonoses—that is, they can spread to humans from other animals. Both rampant and widespread, zoonoses are often at the center of contemporary outbreaks, epidemics, and research. Six out of ten known infectious diseases are zoonotic, and three out of four new or emerging diseases that affect humans come from animals.

For a long time, scientists have speculated that these diseases began afflicting societies around the time animals were domesticated. But they’ve never had genetic evidence or pinned down a specific timeline—until now.

A team of scientists have traced the genetic history of 214 diseases across Europe and Asia over the last 37,000 years. Their findings indicate that the rise of animal husbandry forever shaped humanity’s relationship with disease. However, the timing defied their expectations.

The researchers found that zoonotic pathogens emerged roughly 6,500 years ago and spiked 5,000 years ago. That was surprising because it was several thousand years after humans began domesticating animals in Mesopotamia and southeast Asia. But the evidence says zoonoses initially became prevalent in Asia and Russia as communities transitioned from hunter-gatherer lifestyles to nomadic livestock herding or farming.

Having already tamed horses, communities began to travel in wagons pulled by oxen, which allowed them to voyage farther and exchange goods, ideas, and diseases with other communities. Though some pathogens may have moved from animals to humans even earlier, research suggests these changes made the spread more prevalent.

A vast analysis of DNA from ancient human remains made this study possible. The researchers extracted remnants of microbial genetic material from the teeth and bones of 1,313 human skeletons and identified 5,486 DNA sequences from bacteria, parasites, and viruses. Many remains were found in the same graves, indicating that a single contagion killed multiple people.

The study builds on existing evidence that mutations in these pathogens strengthened the immune systems of the nomads who were the first to get sick, while farmers and hunter-gatherers succumbed to the new diseases. But another study suggested that these nomads’ evolving immune systems might have also made them susceptible to chronic illnesses, like multiple sclerosis.

Understanding the ways pathogens affected humans long ago could help improve modern treatments and methods for preventing disease.

Successful mutations of the past are likely to reappear. So knowledge is important for future vaccines. Knowledge allows us to test whether current vaccines provide sufficient coverage or new ones need to be developed due to mutations.

Scientists analyzed one sample dating to 5,500 years ago, which contained the world’s oldest known genetic trace of yersinia pestis, which caused the plague that killed between 30 and 50 percent of Europe’s population during the Middle Ages. It’s just one example of how zoonoses have had a massive influence on human history and culture.

Other diseases identified in the human remains include malaria (4,200 years old), leprosy (1,400 years old), Hepatitis B (9,800 years old), and diphtheria (11,100 years old).

The work has some limitations. The genes of many viruses are encoded in RNA, which was not studied. The research might have missed some pathogens that were present at low levels. The history revealed is limited to the Eurasian sites where the skeletons were found.

I look forward to the day when my immune system figures out how to avoid covid-19.

 

https://www.msn.com/en-us/health/other/with-ancient-dna-scientists-have-mapped-37-000-years-of-disease-across-europe-and-asia/ar-AA1Jag8R?ocid=hpmsn&cvid=79a5e33a5ea742c0a9a5e8ffd7787b1a&ei=29

Nine-Foot-Long Millipede

A long, long time ago, millipedes were nine-foot-long. Weighing in at 110-pounds, this creature is called Arthropleura and is the largest arthropod to ever live.

This all happened during the Carboniferous period, roughly 300 million to 360 million years ago. The Earth’s atmosphere at that time was rich with oxygen, making it possible for some animals to swell to monstrous size, such as dragonflies with two-foot wingspans.

However, Arthropleura fossils discovered since the 1800s were often only remnants of headless exoskeletons left behind during molting. A new study states researchers have finally pieced together what the animal’s head was like. The breakthrough came from two well-preserved juvenile Arthropleura fossils found in France. These specimens were less than two inches long, but they provided the first-ever glimpse of Arthropleura’s head.

Apparently, this insect’s head was a rough circle adorned with two antennae, a small mandible hidden underneath, and eyestalks protruding from the sides.

Arthropods, are a group of invertebrates that includes crustaceans, spiders, insects, centipedes and millipedes. There has been fierce controversy about Arthropleura’s position on the arthropod family tree since its discovery in 1854. Was it a millipede or a centipede? Scientists weren’t sure.

During examinations of the new, complete fossils, scientists found that it had the body of a millipede but the head of a centipede. It had two pairs of legs per body segment, where centipedes only have one pair per segment. Its jaw position resembles that of a centipede, but its shape and antennae are most similar to those of a millipede. One feature is not seen in any living members of the millipede or centipede families—eyestalks. The eyestalks resemble a crab’s, which could point to the creature having an amphibious youth before becoming terrestrial in adulthood.

Researchers have also concluded that Arthropleura probably chewed on decaying plants like the millipedes of today, rather than hunting prey like a centipede. Its anatomy indicates that it was not carnivorous. It did not have a centipede’s ‘fangs’ or any appendages built for hunting. In addition, having two pairs of legs per segment affected its locomotion and implies it was rather slow.

After piecing together these bits of evidence, the team says the Arthropleura is most closely related to millipedes.

These ancient millipedes lived between 290 million and 346 million years ago, skittering around the Earth’s tropical equator with other massive arthropods, like two-foot-long scorpions. The leading theory for this gigantism is that the oxygen concentration was estimated at 30% during the Carboniferous era compared to the 21% of today. More oxygen in the air may have let insects grow much bigger.

While finding the juvenile Arthropleura has provided some answers, there are more questions to be answered with future fossil discoveries. Did the Arthropleura use tracheae for breathing, or lungs like spiders? That’s just one question that hasn’t been answered yet.

I find modern insects are frequently creepy, at least, to my mind. I definitely do not want to come across a nine-foot-long millipede.

 

https://www.msn.com/en-us/news/technology/fossils-reveal-the-face-of-an-extinct-nine-foot-long-millipede-the-largest-arthropod-to-ever-live/ar-AA1sJDJt?ocid=hpmsn&cvid=ea032899905c4745973f745a67d92256&ei=129

The First Potatoes

The mystery of potato evolution has been solved—and it involved a tomato.

The potato is a global food staple. It was first cultivated thousands of years ago in the Andes of South America before it spread worldwide starting in the 16^th century. But its evolution has long been a puzzle, until a recent analysis finally unraveled its origins.

Scientists say that the potato lineage emerged approximately nine million years ago in South America, through a natural interbreeding event between a wild tomato plant and a potato-like species. This discovery is based on the genomic analysis of 450 cultivated types of potatoes and 56 wild species.

This ancient hybridization event led to the appearance of the potato plant’s distinctive tuber—the enlarged structure housing nutrients underground. While the edible part of a tomato plant is its fruit, the potato’s value lies in this subterranean growth. Researchers also identified two crucial genes involved in tuber formation, which deepens our understanding of this crop.

Potatoes are one of the most remarkable food staples, combining versatility, nutritional value, and cultural ubiquity. Around the world, people eat potatoes using virtually every cooking method. Although stereotyped as carbohydrates, potatoes offer vitamin C, potassium, fiber, and resistant starch. They are gluten-free, low-fat, and satiating. They are a nutrient-dense calorie source.

Resistant starch is a type of carbohydrate that resists digestion in the small intestine and ferments in the large intestine. This means it feeds beneficial bacteria in the gut.

The scientific name for modern a potato plant is Solanum tuberosum. Its two parents were ancestors of a potato-like species now found in Peru named Etuberosum (which closely resembles the potato plant but lacks a tuber) and the tomato plant. These two plants shared a common ancestor that lived about 14 million years ago, so they were able to interbreed when the hybridization event occurred five million years after they had diverged.

The hybridization led to genes being reshuffled so that the lineage produced tubers, which allowed these plants to expand into the cold, dry habitats of the rising Andes mountain chain. During the rapid uplift of the Andes, the potato plant could adapt to the changing environment and thrive in the harsh conditions of the mountains. The tubers stored nutrients for cold adaptation and enabled asexual reproduction to counter the reduced fertility in cold conditions. Therefore, the plant could survive and rapidly expand.

The study’s findings may improve cultivated potato breeding to address environmental challenges that crops presently face. There currently are roughly 5,000 potato varieties. Potatoes are the world’s third most important food crop for humans, after rice and wheat. China is the world’s leading potato producer.

It is hard to remove all harmful mutations in potato genomes when breeding, but this study may show how to make a potato free of harmful mutations using the tomato as the chassis of synthetic biology. It may also lead to a new crop species that would produce tomato fruit above ground and potato tubers below ground.

The potato and tomato belong to the nightshade family of flowering plants, which also includes tobacco and peppers, among others. The study did not investigate the evolution of other tuberous root crops that originated in South America such as the sweet potato and yuca, which belong to different families of flowering plants.

Although the parts of the tomato and potato plants that people eat are quite different, the plants are very similar. If you look at the flowers or leaves of these plants, they are very similar. And if you let your potato plant produce fruits, those fruits look like little green tomatoes. But don’t try to eat them; they are pretty yucky.

 

https://www.msn.com/en-us/news/technology/the-mystery-of-the-first-potatoes-has-finally-been-solved-and-a-tomato-was-involved/ar-AA1JJN5G?ocid=hpmsn&cvid=a1e7bc6999b149a6a70e4275bd5155de&ei=68

Trash in a Cave

A spelunker found trash in a cave, but it was actually evidence of a lost civilization.

A professional cave explorer, on a mapping expedition in the Tlayococ cave in Mexico found a hidden chamber that contained evidence of an extinct civilization.

Yekaterina Katiya Pavlova went to a community in the Sierra de Guerrero to further map the Tlayococ cave. When Pavlova and her local guide reached the bottom of the cave, after exploring all that was already mapped, they opted to head into an unknown passage through a submerged entrance.

The passage led to a previously unseen room where two engraved shell bracelets sat atop stalagmites. They also found another bracelet, a giant snail shell, and pieces of black stone discs similar to pyrite mirrors. All of these things dated to more than 500 years ago.

When archaeologists later descended to the cave, they found more items; a bracelet fragment, a piece of burnt wood, and pieces of a total of eight stone discs (two of which were complete).

All of the bracelets were made from snail shells—probably a marine species—and were engraved with anthropomorphic symbols and figures. The engravings featured S-shaped symbols (known as xonecuilli), zigzagging lines, and circles to create human faces in profile. These designs could be meant to indicate deities.

The archaeologists estimate that the items were left in the cave between 950 and 1521 AD. At that time, the area was known to be populated by the now-extinct Tlacotepehaus ethnic group.

One archaeologist felt the items found could help with interpreting symbolic notions, cultural aspects, manufacturing, and trade of the pre-Hispanic societies in the Sierra de Guerrero.

The archaeologists also determined that the stalagmites were manipulated in pre-Hispanic times to give a more spherical finish, possibly to fit ritual needs. It is felt that the symbols and representations of characters on the bracelets may be related to pre-Hispanic cosmogony regarding creation and fertility. The sealed context helps them understand how the ancient inhabitants may have seen these caves—as portals to the underworld, or as sacred spaces connected to the Earth and the divine.

The black stone discs resemble others from nearby regions, such as El Infiernillo, as well as from distant cultures like Huasteca, Mayan states in east-central Mexico.

Historical reports say extreme cold forced the people living in the Sierra de Guerrero, which is located over 7,850 feet above sea level, to lower altitudes. Little is known about the Tlacotepheuas, other than some 16th-century historical mentions of their presence. The shell bracelets could help tell their story.

 

https://www.msn.com/en-us/news/world/a-spelunker-thought-she-found-trash-in-a-cave-it-was-actually-evidence-of-a-lost-civilization/ar-AA1FF5eD?ocid=hpmsn&cvid=a1e7bc6999b149a6a70e4275bd5155de&ei=77

New Human Species

Scientists have discovered a new human species.

Only one species of hominin exists on the planet today, and that’s Homo sapiens. But throughout more geologically recent Earth history, the human family was a complex tableaux of members. Over the years, scientists have tried to get a clearer picture of that prehistoric story by excavating ancient human sites around the world.

Now anthropologists are illustrating a previously unknown chapter of that story with the introduction of a formerly uncatalogued human species, Homo juluensis.

Homo juluensis means “big head”. This species thrived in eastern Asia from about 300,000 years ago to around 50,000 years ago but then died out. According to the researchers, they likely hunted wild horses, fashioned stone tools, and processed animal hides to survive frigid winters. The breakthrough for discovering this possibly new species came when a team began devising a new system for organizing fossil evidence. They did not expect to propose a new human ancestor species and then to organize hominin fossils from Asia into different groups. But their study clarifies a hominin fossil record that has tended to include anything that could not easily be assigned to Homo erectus, Homo neanderthalensis, or Homo sapiens.

One possible member of the Homo juluensis species isn’t exactly a newcomer. Denisovans were first identified in 2010 by way of DNA extracted from a young girl’s fingerbone found in Siberia, but have not been given a species classification. They could belong to this new species.

Homo juluensis may also solve another mystery of the Xujiayao hominin fossils. These fossils have long perplexed researchers, as the remains display a mix of Homo erectus and Homo sapiens features. These remains have been confused for a variety of taxonomic representations, but scientists note that differences in the (big) cranium, the teeth, jaws, and a few other features indicate a new species. These fossil remains include Penghu 1 (jawbone), Xiahe (mandible), Xuchang (partial crania), and a variety of Denisova fossils.

Although this is a convincing argument that these particular specimens belong to a previously unknown human species, more research is needed. But since these fossils still defy any other species classification, it may only be a matter of time before the human tribe increases by at least one species.