Buzz
In the past decade, DNA research has completely transformed our understanding of human history. Collaborating with archaeologists, anthropologists, and linguistic experts, we've uncovered astonishing findings that have revolutionized our view of human evolution.
Here are some of the most exciting DNA discoveries about our human history from 2020 and 2021.
10. Native Americans and Australasians Have Shared Ancestry in Asia
Before the advent of ancient DNA analysis, we believed that early human migrations were much simpler. However, recent discoveries have proven this notion wrong. We are still piecing together how and when humans first reached the Americas. In 2021, archaeologists in New Mexico uncovered human footprints that are estimated to be 21,000 to 23,000 years old, pushing back the timeline for the first human settlement in the Americas by thousands of years!
DNA analysis of native Australians has revealed that a group, known as the Y population, shares a common ancestry with the indigenous peoples of the Amazon today, but not with those of Northern or Central America. A 2021 study, utilizing one of the largest South American DNA databases, helped trace this connection. The findings suggest that the ancestors of both South Americans and Australians once met in East Asia, where they had children, before some of their descendants migrated to the Americas and followed the Pacific coastline to the Amazon. This indicates that humans entered the Americas from Asia at least twice.
9. The Trans-Atlantic Slave Trade’s Impact on Modern Genetic Diversity
DNA research has also deepened our understanding of one of the most tragic chapters in recent human history: the Trans-Atlantic slave trade. The forced migration of 12.5 million people across the ocean remains the largest in history. New insights, derived from the 23&Me database, have further illuminated the historical context of this atrocity.
The findings support historical records, confirming the brutality of the slave trade. For example, people from what is now Senegal and Gambia were heavily targeted by slave traders for centuries. Yet, their descendants are significantly underrepresented in the USA today, likely due to the high death rates on plantations. Additionally, the study highlights geographical differences in African ancestry and intermarriage. Descendants of Africans in Latin America, where enslaved Africans often had children with indigenous peoples, generally show fewer African genetic markers compared to those in North America, where segregation was more prevalent.
8. Neanderthal DNA Made Its Way Back to Africa
The out-of-Africa theory is widely known: it suggests that most non-African people today are descended from a small group that left Africa around 60,000–70,000 years ago. Along their journey, these early humans encountered other groups such as Neanderthals and Denisovans, with whom they interbred.
Because all this genetic mixing occurred outside Africa, previous research concluded that Africans had no Neanderthal ancestry. Some geneticists even use African DNA as a baseline to measure Neanderthal or Denisovan ancestry in other populations. However, this study indicates that humans also migrated back into Africa, carrying Neanderthal genes with them and contributing these genes to the African gene pool through a process known as gene flow.
The study proposes that we may have overestimated the diversity of Neanderthal ancestry in non-African populations, suggesting that all humans may have a similar amount of Neanderthal DNA. This theory is supported by archaeological findings from the Arabian Peninsula in 2021, which reveal the extent of human migration back and forth between the Middle East and Africa, facilitating the spread of both genes and culture.
7. The Oldest Family Tree in the World
The British Neolithic period, famous for its megalithic structures and burial cairns, has always raised questions about the relationships between the people interred in these monuments. New research has clarified that many of these burial sites were likely family tombs. A study of 35 people buried together in a long cairn in Hazleton, UK, revealed that they were five generations of one extended family. This discovery has allowed scientists to reconstruct the world’s oldest family tree.
The reconstructed family tree reveals a clear biological connection among the male members. One male skeleton seemed to be the father, grandfather, or great-grandfather to nearly everyone else in the tomb. His offspring, both sons and daughters from two different women, were also buried with him. Interestingly, the women and their children were placed in separate sections of the tomb, suggesting that their distinct lineages were recognized even after several generations.
Many of the female skeletons appeared to originate from different regions, potentially joining the family through marriage and moving in with their male partners. This points to a practice among early Neolithic farmers known as female exogamy, where women relocated to their husband’s household, and family identity was passed down from the father. This system bears similarities to how we often inherit our father’s surname in modern society. The burial also included individuals with no direct biological connection to the family, indicating that family bonds could form through other means, such as adoption of stepchildren.
6. The Spread of Asian Languages Through Agriculture
This research integrates genetics with linguistics to explore the spread of language families around the world, an area of study that often intersects with archaeology and history, frequently yielding perplexing and contradictory findings.
The Transeurasian language family spans the entirety of Asia and includes languages such as Japanese, Mongolian, and Turkish. The expansion of these languages across such a vast region has sparked intense debate among scholars, with disagreements on whether the spread was driven by farmers, pastoralists, or migrations during the Bronze Age.
By combining ancient DNA, linguistic research, and archaeological evidence, scientists were able to trace the origins of the Transeurasian language family to early millet farmers in northeast Asia. The language spread in two stages. The first stage involved the slow migration of millet farmers into new regions, taking their language with them. Later, after the late Neolithic period, the Transeurasian people split into five distinct groups, blending with other Eurasian populations. This mixing led to the exchange of linguistic terms, partners, and new farming practices, such as the cultivation of wheat.
5. Investigating the Settlement of Polynesia
The settlement of Polynesia, much like that of the Americas, is a subject of much debate. Polynesia is an island region scattered across the world's largest ocean, and its early settlers traveled between islands in open canoes. For years, there was disagreement among scientists about whether Polynesia was settled by people from South America, Australasia, or a combination of both.
In a study that analyzed the genomes of 430 individuals from 21 islands, it was discovered that the settlement of Polynesia began around the 11th century from Samoa. From there, the settlers moved eastward, potentially settling on islands that were relatively new, having only existed for a few centuries. They reached Easter Island around 1200, journeying in small groups of fewer than 200 people. They navigated using the stars and left behind the famous statues of Easter Island.
4. Who Has the Most Denisovan DNA?
This list highlights the fascinating insights that ancient DNA has provided into the intricate and surprising patterns of human migration. The Denisovans, first identified in a Siberian cave in 2010, were found to share the most common ancestry with people living today in Southeast Asia, based on genome comparisons.
Building on earlier studies, this research reveals that the Ayta Magbukon, a native group in what is now the Northern Philippines, have the highest concentration of Denisovan DNA—up to 5% of their genome. The scientists suggest that Denisovans must have lived in Southeast Asia at least 50,000 years ago.
The Philippines have garnered increasing attention recently. In 2019, researchers announced the discovery of a new species of small hominid, Homo luzonensis, which lived on the islands around 60,000 years ago. This discovery suggests that Southeast Asia, including the Philippines, was a vibrant hub with diverse human species coexisting and interacting with each other.
3. Future Research Could Involve DNA from Nits!
While it doesn’t directly illuminate our understanding of human history, this intriguing piece of news shows how human DNA might be studied in the future, Jurassic Park style. It turns out human DNA can be preserved in the cement that head lice use to attach their eggs to our hair! Scientists employed this method to analyze hair from Argentinian mummies that lived 1,500 to 2,000 years ago. Imagine combing through ancient mummy hair with a nit comb!
In addition to being revolutionary (and perhaps slightly unsettling), this method could offer a more sustainable way to extract ancient human DNA. Unlike traditional methods that involve extracting DNA from bones or teeth, which often destroy the original sample, this technique preserves the sample. As a result, archaeologists may be more open to conducting DNA analysis on rare specimens. Furthermore, it could serve as a way to obtain DNA from countries that might hesitate to allow Western scientists to export human remains.
2. The First Europeans and Native Americans
By now, it’s clear that ancient DNA has revealed some surprising and complex truths about the movement of humans. It can also provide puzzling results. For instance, two recent studies analyzed the genomes of individuals who lived in the Bacho Kiro cave in Bulgaria around 45,000 to 42,000 years ago. These remains are considered the oldest Homo sapiens fossils found in Europe.
The findings showed that these ancient people had Neanderthal ancestors just a few generations back, suggesting that interbreeding with Neanderthals was likely quite common. Scientists then compared the Bacho Kiro genomes with those of modern populations to trace their relations. Surprisingly, they discovered that these individuals were ancestors of Native Americans and East Asians. Additionally, the study revealed that later remains from the same site, dating from a later Paleolithic period, were more closely related to modern Europeans, highlighting the ongoing mixing and movement of populations.
1. Humans Fought Coronavirus Outbreaks 20,000 Years Ago
Did you think coronavirus was something new? In fact, ancient viruses have left traces in our DNA that researchers can study. In this particular study, scientists found that humans have been encountering coronavirus variants since the Stone Age! They also reinforce previous findings suggesting that interbreeding with Neanderthals may have made Europeans more susceptible to the coronavirus.
The first corona epidemic took place in East Asia about 20,000 years ago, or roughly 900 human generations. It lasted several generations, enough time to exert what scientists refer to as 'selective pressure' on humans. The initial strain was likely more dangerous than today’s Covid-19 variant, but it became less lethal over time. Although the researchers note that it doesn’t seem to have affected modern East Asians' vulnerability to the virus, the field of evolutionary medicine could still play a role in developing cures or combating future outbreaks.
