In the last ten years, technical advances in DNA analysis have revolutionized the way we can see humankind's past. In coordination with archaeologists, anthropologists and language experts, researchers have made amazing discoveries that have changed our view of humankind.
Below we list the most prominent results of the latest discoveries about humanity's past from DNA analysis in 2020 and 2021.
10. The aborigines of America and Australia have common roots in Asia
Scientists assumed that human migration in the past was rare and simpler than it became later, but the results of research from the past years revealed the opposite. In 2021, archaeologists in New Mexico found human footprints dating back 21,000-23,000 years, thousands of years before the colonization of the Americas!
DNA analysis of Aboriginal Australians also showed that they had common ancestry with Aboriginal people living in the Amazon today, not North or Central America.
9. The slave trade affected genetics
The transatlantic slave trade was the largest forced migration in history, with 12.5 million people transported in slave ships over hundreds of years. A recent analysis using 23&Me's database data helped us understand more about slave migration and its effects, according to the science journal Nature .
The researchers' findings support historical records of the brutality of the slave trade. For example, the inhabitants of what is now Senegal and Cambodia have been attacked by slave traders for centuries, but their descendants are largely underrepresented in the genetic makeup of today in the United States. This may be due to the high death rates on farms.
8. The DNA of Neanderthals dates back to Africa
Historically, the theory of early migration from Africa prevails and that most non-African humans today are descended from a small group of humans who left the continent about 60,000-70,000 years ago. They met other human groups such as Neanderthals and Denisovans and multiplied.
Because all this mixing occurred outside Africa, previous studies had assumed that Africans had no Neanderthal ancestors. However, it turned out that the African groups brought with them the genes of Neanderthals and spread them with the African gene pool in what is known as gene flow .
As a result, all humans possess a nearly equal amount of Neanderthal DNA.
7. The oldest family tree in the world
Neolithic Britain is known for its gondolas, colossi and other stone structures, which often house many people buried together. So far, the relationship between the human remains buried together remains unclear. But we now know that they may have been family graves.
A study using data from 35 people buried together in a tall mound in Hazleton, UK, showed that they were five generations of the same family. Scientists used the relationships between these individuals to recreate the world's oldest family tree, Listverse reports .
The family tree showed a direct biological relationship between males. One of the skeletons in the tomb seemed to be the father, grandfather, or great-grandfather of all the other males in the tomb. His children and grandchildren from two different women were buried with him. The two women and their sons were buried in separate places in the cemetery, which indicates that ancient humans recognized the idea of different lineages.
6. The spread of Asian languages through agriculture
The Altaic language family covers the entire continent of Asia, which includes Japanese, Mongolian and Turkish. The spread of languages over such a large area has always been a matter of intense disagreement among scholars, who did not agree on whether the spread of the language was due to farmers, pastoralists, or to Bronze Age migrations.
Scientists used ancient DNA, language studies, and archaeological remains in order to find an answer. The study concluded that the homeland of the Altaic language family may be traced back to the early millet farmers in Northeast Asia. Then it spread in two stages; The first stage involved the expansion of millet farmers into new lands, spreading their language with them.
After that, the people of the Altaic languages split into five "subgroups" after the Late Neolithic and mixed with other Eurasian peoples, intermarried with them, exchanged linguistic terms and learned new ways of life such as growing wheat.
5. Understand how humans arrived and settled on the island of Polynesia
Like the Americas, the way humans settled on the island of Polynesia is a controversial scientific topic. And the island of Polynesia is the region of islands that spread across the largest ocean in the world, and people move from one place to another using open boats, according to ABC News .
For a long time, scientists did not agree whether the inhabitants of South America or the inhabitants of Australia were the ones who settled on the island of Polynesia, or both!
This study used the DNA of 430 modern people from 21 islands, and found that the settlement of Polynesia began around the eleventh century from Samoa, as humans moved east, possibly colonizing islands that did not exist until hundreds of years ago. They finally reached Easter Island around 1200.
4. The most prominent genetic content of Denisovans is found in…
The Denisovans were first discovered in a cave in Siberia in 2010. When comparing the genetic content with modern people, it was found that they share the genetic content more with those who currently live in Southeast Asia!
This study builds on previous research work that found that the indigenous group Aita Magpukon (living in what is now the Northern Philippines) have the highest content of Denisovans DNA (about 5% of their genetic makeup)! From this, scientists concluded that Denisovans existed on the islands of Southeast Asia at least 50,000 years ago.
The Philippines is getting more attention. In 2019, researchers announced the discovery of a new species of hominin, called the Callao man, that lived in the north of the islands about 60,000 years ago.
3. Humans fought the coronavirus outbreak 20,000 years ago
Do you think the corona virus is new? Ancient viruses leave their imprint on their DNA, which researchers can analyze and find. In this study, scientists discovered that humans have always dealt with mutated types of the Corona virus since the Stone Age!
The study also supported previous research indicating that mixing with Neanderthals made Europeans more vulnerable to infection with the Corona virus.
The first coronavirus pandemic appeared in East Asia about 20,000 years ago, or about 900 human generations ago. The pandemic lasted several generations, long enough for what scientists call "selective pressure" to appear on humans.
The early strains of the virus were more dangerous than the modern Covid-19 mutant, but they became less lethal over time.
2. Early Europeans and Native Americans
Two recent studies analyzed the genetic content of people who lived in the Bacho Kiro Cave in Bulgaria about 42,000-45,000 years ago. These skeletons are also among the oldest "Homo sapiens" remains in Europe.
The researchers found that these humans had Neanderthal ancestors "several generations ago", suggesting that mixing with their Neanderthal neighbors was very common.
The study also discovered that human remains belonging to a later date from the Paleolithic period in the same area are more closely related to modern Europeans, which shows that the population groups were in a state of permanent transition and mixing.
1. DNA samples from lice can be used in future studies!
It is clear that human DNA is preserved in the layer to which head lice attach their eggs to our hair! Researchers have collected hair samples from Argentine mummies that died 1,500-2,000 years ago. Can you imagine examining the hair of ancient mummies with a lice comb?
Although it may seem revolutionary (or a bit exaggerated), this method may be the most appropriate and sustainable method for extracting ancient human DNA. Current techniques that extract DNA from bones or teeth destroy the original sample. That is why many archaeologists are reluctant to perform DNA analysis on their rare specimens. It could also be ideal for taking DNA samples from countries that are reluctant to allow Western scientists to move human remains.