10,500-Year-Old Face

Scientists have reconstructed the face of a 10,500-year-old woman using DNA. The woman lived in what is now Belgium.

The woman had blue eyes, and her skin was slightly lighter than most other Mesolithic-period people living in Western Europe when compared to the analyses made to date. According to archaeologists, the woman came from the same population group as the Cheddar Man, who lived in what is now the United Kingdom at around the same time. The Cheddar Man had even lighter skin than the woman.

These findings challenge previous assumptions that European hunter-gatherers shared the same genetic makeup. It also demonstrates that even that long ago, there was considerable variation in skin color.

The skull indicated the woman was between 35 and 60 years old. Her nose had a high nasal bridge, similar to Cheddar Man. And she had strong brow ridges despite being female.

The woman’s remains were found in an archaeological dig in 1988-1989 in the Margaux cave in Dinant. The bodies of 8 other women were also found there. This was deemed unusual as most Mesolithic burial sites contain a mixture of men, women, and children. Many of the skeletons were sprinkled with ochre, a pigment made of iron oxide, clay, and silica. Most of the bodies were carefully covered with stone fragments, but one individual had cut marks on her skull that were made after her death.

This burial cave was used over a period of several hundred years, which indicates that it was a place of memory that people would go back to despite their mobile lifestyle. Such findings point to complex burial customs and raise questions about the social structure and cultural practices of this early community.

One archaeologist found the ancient woman’s skin color a bit surprising but indicated there is a limited pool of Mesolithic people to make comparisons. Apparently, all Western Europe individuals who have had their DNA analyzed belong to the same genetic group.

When these remains were first recovered, there was no way to conduct research into ancient DNA. But techniques have been developed since then. The DNA was taken from the woman skull, which allowed a very detailed reconstruction.

The woman’s coloring is based on DNA, while such things as jewelry and tattoos are based on data from other excavations in the River Meuse basin. This data also helped build a picture of her daily life.

At a former campsite on the banks of the river, scientists found stone tools, fish remains, and bones from wild game, which proved these people were nomadic. They were forced to move through the landscape because they were dependent on natural resources such as plants, fish, and wild game.

There are still a lot of questions about these Mesolithic communities, which were the last hunter-gatherers in Western Europe.

 

https://www.msn.com/en-us/news/world/scientists-reconstruct-10-500-year-old-woman-s-face-using-dna/ar-AA1H29cO?ocid=hpmsn&cvid=8bfc0715dd4c4b0f92e756baa7f46623&ei=15

The Tree of Life’s First Branch

There was one common ancestor for all animals on Earth. If you trace the history of any creature—from humans to slugs—you’d eventually follow all the branches of the animal tree of life back to its trunk.

Coming from the other direction, that trunk had to branch off at some point, or we wouldn’t have a diverse collection of animals. Unfortunately, that first split has been elusive to scientists because it took place around 600 million years ago.

Scientists have figured out that the first split resulted in the birth of two creatures. One was the ancestor of almost all animals, while its “sister” gave rise to just one group of modern animals.

For decades, scientists have debated which group of animals came from the “sister” ancestor. They had two contenders—sea sponges and comb jellies. Thanks to new methods that enable researchers to analyze these animals’ chromosomes, they think they have the answer.

The key was to look not just at what genes each animal had, but where those genes were located on the chromosomes. As a creature evolves, chromosomes will rearrange, and genes will move around. But once genes move, it’s almost impossible for them to return to their original position. Therefore, whichever animal showed the least re-shuffling of genes on its chromosomes must have come into existence first. Out of the two options, whichever animal has the least shuffling is the sister.

The team compared the placements of certain groups of genes in sponges and comb jellies to the placements of those same groups in their closest single-cell non-animal relatives. (The single-cell relatives would have been closely related to the “trunk” organism and would have evidence of what that original genome looked like.) The closer an organism is to that genome, the less it has changed, and the more likely it is the sister.

In both the non-animals and the comb jellies, they found 14 groups of genes located on separate chromosomes. But in the sponges, they found those 14 groups were rearranged into 7 groups, which indicated they split from the original genome later than the comb jellies.

Consequently, the sister to all other animals, the first to branch off, and the most genetically isolated animal is the comb jelly.

Besides answering a long-standing biological question, scientists can investigate what this knowledge tells us about animal evolution, and the mechanisms of that evolution. And so the search for more answers continues.

Thank goodness they figured that out. I don’t think I could have remained sane another day without knowing which animal came first.

 

https://www.msn.com/en-us/news/technology/scientists-have-found-the-first-branch-on-the-tree-of-life/ar-AA1LAkS2?ocid=hpmsn&cvid=cddbc1e105374c51afa382b8cdd3674d&ei=18

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

An Ice Age Infant

By analyzing the DNA of a baby found in southern Italy, scientists have a striking picture of the young boy. The poorly developed child lived during the Ice Age about 17,000 years ago. He likely had curly dark hair, brown skin, and blue eyes.

In 1998, his remains were discovered in the Grotta delle Mura cave in Monopoli, Puglia. The baby’s bones were carefully covered with rock slabs. With no grave goods, the simple burial was the only grave in the cave.

The largely intact skeleton revealed the child was about 2.5 feet tall when he died. Recent dental examination revealed he was between 8 and 18 months old. Radiocarbon dating stated the remains were 16,910 to 17,320 years old, meaning he lived a few centuries after the Last Glacial Maximum, when glaciers covered a quarter of the planet’s land, some 20,000 years ago.

Ancient skeletons found in warm climates are often too degraded for any significant genetic analysis. But the cave was so cool, the boy’s remains were well preserved. Researchers were able to recover about 75% of the boy’s genome, which is remarkable.

His skin was darker than most modern Europeans’, but his pale blue eyes match those of other western European hunter-gatherers. The infant appears to be related to the Villabruna cluster, a group of post Ice Age people who lived up to 14,000 years ago. This suggests the Villabruna line began in southern Europe well before the end of the Ice Age.

Researchers also determined his cause of death. He had an inherited condition that causes the heart muscle to thicken. This results in fatal congestive heart failure.

Nine accentuated lines marking the baby’s teeth indicate “physiological stress events” that occurred before and after birth. Isotopes in the teeth suggest that his mother stayed in one area during pregnancy and may have been malnourished. His birth was likely difficult, according to a fracture in the baby’s collarbone.

 

https://www.msn.com/en-us/news/technology/an-ice-age-infant-s-17-000-year-old-dna-reveals-he-had-dark-skin-and-blue-eyes/ar-AA1sFhf0?ocid=hpmsn&cvid=ed46623d933043f19069e3bf9a8f9350&ei=23

Just Another Sink Hole

When you live in Florida, you get used to hearing about sink holes. When one opens up, it is filled with sand and rocks and everyone hopes it doesn’t continue to cause problems, especially if it occurred in a road. Before we moved here, I occasionally heard about a sink hole opening in other places, and they always seemed to swallow a car or two. But sink holes can be fickle things; some start out small and continue to grow until they are huge. Some seem to be bottomless pits that refuse to be filled, no matter how much sand and rocks are thrown into them.

Recently, I heard about a ‘sink hole’ in northern Wyoming, near the base of the Bighorn Mountains. Called Natural Trap Cave, it was discovered in 1970, when it was believed to be some 25,000 years old. Theory says that it opened up alongside a migratory trail used by many species, and they just kept falling in.

Located in a National Park, the sinkhole is 15 feet wide and (currently) 85 feet deep. Chances are that once an animal fell in, it wasn’t getting back out again. When it was first discovered, there was some digging of the bottom of the hole for a few years before it was closed up and left alone. In 2014, a new batch of scientists returned to do some more digging. They were only there for 2 weeks during August of that year, and before they could dig, they had to figure out how to safely get themselves and their gear to the bottom and up again. But what they found when they did get there was stunning; North American lions and American cheetahs, both of which went extinct about 12,000 years ago. During the 70s, scientists had discovered mammoths, short-faced bears, giant camels, and collared lemmings in the pit. Also discovered (but I’m not sure when) were dire wolves, tiny rodents that need to be studied by microscope, bison, grey wolves and horses.

Even though it was August, the scientists reported the hole was like a refrigerator. So much so that some of the skeletons still include DNA, so there will be huge strides in our knowledge of prehistoric genetics.

The 2014 group of paleontologists planned to continue their excavations another 2 years. They estimated that the depth of the pile of dead creatures could be 33 feet, and the digs of the 70s and 2014 had barely scratched the surface. With that said, they thought the bottom of this heap might have animals 100,000 years old.

If that turns out to be true, then this sink hole can’t be only 25,000 years old. That would make this one great, great grand-pappy of a sink hole. And amazingly stable for a sink hole, too.

http://www.telegraph.co.uk/news/worldnews/northamerica/usa/11026162/Hundreds-of-Ice-Age-fossils-found-in-ancient-sinkhole-in-Wyoming.html

http://westerndigs.org/wyoming-cave-yields-a-trove-of-ice-age-fossils-and-ancient-animal-dna/

http://www.ibtimes.com/25000-year-old-sinkhole-wyoming-treasure-trove-ice-age-fossils-1655030

https://weather.com/science/news/wyoming-cave-dig-reveals-hundreds-ice-age-fossils-20140809

Science Quiz

For 7 years, I’ve tried to ‘update my science [knowledge].’ I’ve always wanted to write science fiction, but my last science class was a quarter century ago, the one before that in 1970. I’d been busy working full time, raising kids, and so on. So when I retired and started writing science fiction, I found the vast research I did – and the results produced – shot huge holes in my time, the story background, and the plot I had picked.

Therefore, I subscribed to magazines, watched science and history documentaries, did other ‘educational’ things. I love to learn but… have I caught up? Am I ready to write science fiction?

Last week, I received the Jan/Feb 2017 issue of Discover. It includes a list of the ‘Top 100 Stories of 2016’. As I read through some of this list and the entry for each article, I realized I was not familiar with everything listed. Have I failed?

I decided to keep track of which stories I had and had not already heard about. Now, I don’t get to read a magazine in one sitting, so as of today, I’ve only gotten to #40. Don’t worry, I will finish this issue, but in the meantime, how many of these 40 items had I already learned about before this issue?

First, the ones I had no knowledge of:

#4. Oldest Human DNA Revises Our Family Tree (I’d heard of Neanderthals & Denisovans, but not this particular story)

#5. Biologists Create Organism with Smallest Genome

#9. New Particle Fizzles, Leaving Physicists to Soul Search

#10. Did Lucy Fall and Not Get Up? (I knew about Lucy, but this was a new hypothesis that she died by falling out of a tree.)

#11. Bangladesh Sits Atop Potential Major Quake Zone

#12. Big Data May Lead to Earlier Alzheimer’s Diagnosis

#18. Electrons ‘Split’ in New Form of Matter

#19. Science in a Post-Brexit World

#22. NIH Proposes Lifting ‘Chimera’ Research Ban

#23. Picky Primes (Prime numbers are not as random as believed.)

#24. Finding China’s Great Flood

#27. Battle for Access (Should scientific papers be available to all, or only those who can afford to subscribe to scientific journals?)

#28. A Bone to Pick about Philistines

#29. Go, Go AlphaGo (Computer learns game, beats human champion.)

#31. Pushing the Limits of Life in the Lab

#32. Disrupting Dopamine Dogma

#35. Mathematicians Find the Answers (I was unaware of this question.)

#36. T. Rex Evolution: Smarts First, Size Second

#37. The Rise and Fall of Theranos (Fake medicine exposed)

#39. Plenty of Room at the Bottom (Saving data with chlorine and copper)

#40. Pluto’s Hidden Ocean (I knew it had one, but this article is about how it’s freezing, breaking Pluto apart.)

And the ones I was familiar with:

#1. Einstein’s Ripples in Space-Time

#2. Earth’s Surprise Neighbor Hints at Exoplanet Abundance (planets of Proxima Centauri)

#3. A New Enemy Emerges (zika and mosquitoes)

#6. The Pace – and Problems – of Climate Change Accelerate

#7. Can America Avoid Another Flint?

#8. Looking for Planet Nine

#13. Persistent Heat Decimates Coral Reefs

#14. The Ozone Hole is Finally Healing (Still has a long way to go.)

#15. More Hobbitses, Prescious! (More remains of hobbit-sized hominids found.)

#16. We Are All Africans

#17. The Falcon Has Landed, Now SpaceX is Eyeing Mars

#20. Ceres Hosts an Ice Volcano

#21. Regulating the Brave New World of Human Gene Editing

#25. The End of the Periodic Table? (How many more elements can scientists make?)

#26. Drug Couriers for Brain Injuries

#30. Crowdsourced Study Pinpoints Depression Genes

#33. Planets of the Milky Way

#34. Superbug Arrives in the US (Bacteria not deterred by any known medicine.)

#38. A Sharp Find (Ancient sword found in Denmark)

How did I shape up? Hmm, 21 stories I did not know; 19 I was semi-familiar with. If I were in school, that would be less than 50%, a solid F. But, I can’t know everything, so I don’t feel bad. Besides, some of these articles have hinted at background knowledge or even a story plot. I am stoked!

What have you learned in the past 7 years? I bet it’s a lot, whether science or not.

Nomads

One of the panels I’ve given at several conventions this year has been “Where did the first Americans Come From?” In that panel, we discuss 6 different theories held by various scientists, from the one most of them agree is most likely to the one most people ridicule.

In doing my research for that panel-and just generally reading up on science subjects that spark my interest-I have arrived at one conclusion about humans and our ancestors... We have been nomads pretty much as long as we’ve been hominins. An article I read this past week has done much to confirm that, in my mind.

The article was actually about the Tibetan people and how they can thrive in the rarified atmosphere of the high altitudes where they live. Genetic studies have shown that most Tibetans (and a much lower percentage of the Han people in China) have an archaic gene. Not a mutant gene. An archaic gene inherited from a type of human that no longer exists.

This dead species of human is called the Denisovans. They are believed to have been related to-but distinct from-The Neanderthals (also extinct). And scientists probably would not know anything about the Denisovans at all, if someone had not found a single finger bone and 2 teeth in a Siberian cave. DNA study of those 41,000-year-old bones showed they belonged to people who were not Neanderthals, but definitely not modern human, either.

A genetic study of the Tibetan and Han people revealed they had inherited just enough Denisovan genetics to have the ability to up the production of hemoglobin in their blood. This increases their ability to get enough oxygen to their cells in an environment where most of us would have a tough time, due to lack of oxygen.

So, in order for the more modern humans to have bred with Denisovans (or the Neanderthals, for that matter) those earlier versions must have not just left Africa at some earlier time, but spread out across all of Eurasia. After all, Siberia is just about as far away from Africa as they could have gone. And later groups of hominins and humans would have exchanged DNA as they moved into the area, or passed through the area, or whatever.

If humans were not naturally nomads, they might never have left Africa, and then where would we be? Well, I guess we might all still be in Africa.

Distant Ancestors

In my never-ending quest to get my science knowledge a little more up-to-date (the better to write science fiction), I periodically surf the net in search of interesting but not too complicated science articles. This past week, I ran across quite a few articles about Neanderthals; when they died out, where they died out, why they died out, and so on.

You know about the Neanderthals; big heavy brows, broad flat noses, short chunky bodies. All those characteristics were helpful to them as they lived in Europe during ice age conditions. I don't remember how the heavy brows were helpful, but the noses helped warm the frigid air before it hit their lungs, and their compact bodies conserved body heat.

Up until recently, it was believed that the last of the Neanderthals died out in the area of Spain about 40-42,000 years ago, helped along on the road to extinction by the arrival of 'modern man' into Europe shortly before the demise of the Neanderthals. It wasn't certain that the two groups came into direct conflict and poked holes into one another, but if nothing else, they were both vying for the same food supply, and it was thought Neanderthals just couldn't effectively compete.

According to what I read this week, a new dating technique for old skeletons and other remains has now pushed the demise of the Spanish Neanderthals to around 50,000 years ago. So, were they completely gone before 'modern man' arrived? Probably not. The scientists were going to be conducting more tests on other sites, but it was rather expected that the new dating technique would also push back the date of modern man's arrival into Europe a similar amount of time. So, other than changing the position of a couple dots on a timeline, this didn't really change much.

On the other hand, genetic anthropologists have been analyzing tiny bits of Neanderthal DNA wherever they could find it, and by combining the results of all their work, they figure they've got about 12% of a complete Neanderthal DNA workup.

And it seems Jean Auel was correct when she wrote in Clan of the Cave Bear that Neanderthals and modern man had babies together. Scientists have compared current DNA to Neanderthal DNA and found that modern people have as much as 2% of their DNA from Neanderthals. The amount varies between ethnicities, but it's there.

So... I blame my son's unibrow on Several-times-great-grandfather Oogh, of the German Neanderthals.

Dogs of the World

I like dogs. (I love cats, but that's another story.) Lately I've been reading a few articles having to do with the genealogy of dogs, particularly in the Americas.

When I was a kid, school described North American indian tribes as having horses and ponies. I was too young to question that at the time. Later, it was explained that the ponies originated with the Spanish explorers in Mexico, and that they quickly spread throughout North America. I assumed the indian dogs were a similar story.

But it turns out that dogs had already been here when the Spaniards, the Vikings, and other Europeans arrived. It had been assumed that when the indigenous people died out, their dogs died with them, having no one to take care of them.

These recent articles explained that the original 'American' dogs came over the land bridge from Asia and Siberia with the people who became indigenous indian tribes. Those dogs did not die out and were not supplanted by European dogs. They survived, interbred with the European dogs, and are still here.

This was discovered by comparing the DNA of American dogs with that of Asian and European dogs. The American DNA was much closer to the Asian DNA than the European DNA. This was true as far east as Greenland.

So the Mexican hairless, the Peruvian hairless, and any number of other breeds are about as American as they can get.

My family has a mutt. He's a great addition to our family, and I assume he's an 'American' mutt. How about you? Tell me about your dog.

Who's Your Distant Ancestor?

Back when I was in grade school, I remember one of my sisters preparing a display for her high school science fair project. In that project, she compared Neanderthals to Cro-Magnons. I don’t remember what kind of grade she received, but I found her project fascinating. Two types of humans, living at the same time! I wondered what their interactions would have been like.

Since then, the same question has been explored in various medias. Jean Auel’s Clan of the Cave Bear made a big splash with readers as it followed the life of a young Cro-Magnon, also known as a modern human, who was raised by Neanderthals, if I remember correctly. Various educational shows on TV have been made about the Neanderthals, the Homo Sapiens, how they were different, how they were alike, and how they might have interacted before the Neanderthals died out.

The impression I’ve gotten over all these years was that scientists didn’t feel these two species of humans had interbred, and I wondered why they thought that way. Neanderthals are depicted as kind of squat, hairy, with a heavy brow, broad noses and receding chins. I could look around and see people who had those attributes, although it’s usually one per person, not all of them. But no, it seemed we were determined to blame our own ancestors for killing the last of the Neanderthals.

At last, a skeleton has been discovered in northern Italy that appears to be that of a mixed breed. Although mostly that of a modern human, the jaw displays a receding chin. The DNA reveals this person had Neanderthal mitochondrial (maternal) DNA. So it would seem the two species did interbreed, at least once.

Which opens up a whole new mess of ancient ancestors we didn’t realize were in the gene pool.

Sometimes when I’m working out the background for a story, I pick 2 or 3 genetic things to track throughout the population and then work out how those attributes manifest in the population over the generations. The gene for dark hair, for instance, will dominate a gene for lighter hair, and blond will dominate red hair. But after a few generations of almost all the people having dark hair, you will start getting a generation or two of lots of blonds, and a few redheads will crop up. The number of blonds will ebb and flow; the number of redheads tends to remain fairly steady.

I never thought to track the occurrence of receding chins.