Jewish American Heritage Month

Posted By admin on September 8, 2022

Dating is everything in archeology. Exciting discoveries of ancient cemeteries or jewelry may make the headlines, but for scientists, such a discovery only makes sense if we can tell how old the artifacts are.

When chemist Willard Libby developed radiocarbon dating in 1946, it was a breakthrough for archeology and he was awarded the Nobel Prize for his achievement.

Today, people underestimate radiocarbon technology, and many people think that you can use radiocarbon on any human remains. Scientists wish this were true, but in reality, only 50% of bodies can be dated using this method, as some skeletons lack sufficient organic material or are contaminated.

Many exciting finds have been incorrectly dated or not dated at all, meaning that clues to the skeletons from the past are still locked away. But my team may have found the key: DNA dating.

To understand why we need DNA dating, you need to know what radiocarbon dating is. It allows us to date organic material (which is younger than 50,000 years) based on chemical reactions that the body changes with the environment after death.

Carbon is found in all living things and is the backbone of all molecules. When we eat, we absorb it and release it into the atmosphere. Radiocarbon dating compares three different isotopes of carbon (a type of atom).

The most abundant carbon-12 remains stable in the atmosphere. As one of the other isotopes it is a good measure of the age of skeletons, carbon-14 is radioactive and decays over time.

The radioactivity of the carbon-14 left behind reveals their age, as animals and plants stop absorbing carbon-14 when they decay. But there is a catch. Low amounts of organic material, feeding of dead person or animal, and contamination with modern specimens can skew the calculation.

Only differences in dating between laboratories can be up to 1000 years. Queen Its like dating Elizabeth in the time of William the Conqueror.

An alternative to radiocarbon dating is to use archaeological artifacts found next to human remains. Lets say we find a skeleton carrying a coin minted by Julius Caesar, which will work. But this rarely happens.

The oldest human remains in Afghanistan were found in the Darra-i-Kur cave in Badakhshan. Based on radiocarbon dating of soil and charcoal, archaeologists believed that a Neanderthal skull fragment was from the Paleolithic age (30,000 years ago) and is often cited as the best example of Paleolithic bones.

The bone was radiocarbon and DNA dated to the Neolithic age (4,500 years ago). He was the first ancient human from Afghanistan to sequence their DNA.

Scientists already know about DNA mutations that can indicate where someone came from. My team has created a GPS tool for genomes that helps us identify Ancient Ashkenazi as the birthplace of Ashkenazi Jews and the Yiddish language. There are also DNA mutations that help tell us how long ago someone lived.

An example is the LCT gene mutation that allowed our ancestors to process lactose. It has increased rapidly since the first day it emerged in an advanced form in the Neolithic age (10,000-8000 BC). Thus, we can date ancient genomes without LCT gene mutations to pre-Neolithic age.

My team developed the temporal population structure (TPS) algorithm tool and used it to date 5,000 ancient and modern genomes. There are tens of thousands of mutations that increase or decrease over time. TPS identifies these mutations and the period with which they are associated and classifies them into eight broad periods.

Every ancient people is represented by the signatures of these eras. TPS uses a type of artificial intelligence known as supervised machine learning to match these signatures to the ages of the skeletons.

One way to test a dating method is to compare the age difference of related skeletons. This could work if the skeletons are complete enough to estimate their age. For example, you would expect father and son skeletons to date to a period of about 17 to 35 years.

In a blinded test, TPS dated the skeletons of close family members to a reasonable period of 17 years, compared to 68 years in an unblinded test for other dating methods. (A blind test is when information that could affect experimenters is retained until the experiment is complete.)

One of the most controversial places for ancient dating is the Brandsek cemetery in Czechia. Brandisek tombs dating to the Bell Beaker period were explored between 1955 and 1956.

Archaeologists unearthed tombs, half of which were destroyed by mining operations. They found 23 people from 22 graves, as well as artifacts such as pottery, a bone necklace, and flint arrowheads.

In both a radiocarbon and archaeological context, the site has been dated to the Bell Beaker period (4,800-3,800 years ago). However, the same study radiocarbon gave the approximate (5,500 years ago) date of one of the skeletons.

Given that only two bodies could be radiocarbon dated, it was difficult to tell whether the dating was incorrect or whether this was a site of ceremonial significance for thousands of years. Our DNA study of 12 skeletons from the area confirmed that the suspected skeleton was about 1,000 years older than the others.

Our results confirm that this site has been a cemetery since the Neolithic period. This also explains why the site has architectural features not usually associated with Bell Beaker tombs, such as stone tombs.

Although TPS performs well, it is not a substitute for radiocarbon dating. Its accuracy depends on a dataset of ancient DNA. TPS can set dates for humans and livestock for which extensive historical data is available. But those who want to travel back in time to meet an ancient elephant or monkey are on their own.

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Read more from the original source:

Radiocarbon dating only works halfway we may have the solution - PiPa News

Category: Ashkenazi
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