Neanderthals were not entirely wiped out, as suggested by recent DNA discoveries.
Stormin' through Ancient Times: The Intertwined History of Humans and Neanderthals
Ever since the discovery of ancient Neanderthal bones, curiosity about these far-off relatives has always been alive and kicking. Were we similar yet different? How did we coexist with them? And what about the Denisovans?
Recent research led by a team from Princeton's Lewis-Sigler Institute for Integrative Genomics has shed some light on our complex past, revealing a history of genetic intermingling that shows humanity and Neanderthals were closer than we once thought.
According to study co-author Liming Li, "This is the first time geneticists have identified multiple waves of modern human-Neanderthal admixture."
Our early ancestors separated from the Neanderthal family tree approximately 600,000 years ago, developing modern characteristics around 250,000 years ago. For the following 200,000 years, modern humans interacted with Neanderthal populations, as revealed by the new research.
Curious about how Neanderthals fit into our story, the team conducted a comprehensive study of the genetic flow between these groups using genomes from 2,000 living humans, three Neanderthals, and one Denisovan. Utilizing a tool called IBDmix, which employs machine learning to decode genomes, they mapped the genetic intermingling over the past 250,000 years.
Previously, researchers compared human genomes against a reference population thought to have little Neanderthal or Denisovan DNA. But, the Princeton team found even those reference groups had trace amounts of Neanderthal DNA, likely brought by travelers over the centuries.
The researchers identified three waves of contact: 200-250,000 years ago, 100-120,000 years ago, and the largest around 50-60,000 years ago, challenging previous genetic data that suggested modern humans stayed in Africa for 200,000 years before dispersing 50,000 years ago.
By searching for modern-human DNA in Neanderthals, rather than the opposite, the team discovered that the Neanderthal population was smaller than previously believed. Genetic modeling usually uses gene diversity as a proxy for population size, but this research showed that much of the apparent diversity in Neanderthals came from modern human DNA. The estimated Neanderthal population size was revised down from around 3,400 to 2,400 breeding individuals.
Tracing our shared history with the Neanderthals and Denisovans, it appears that our ancestors were explorers, moving across lands and encountering other hominins more than previously recognized.
Once regarded as sluggish and unintelligent, Neanderthals have since been recognized as skilled hunters and advanced toolmakers who adapted well to the cold European climates. Their story is one of resilience, survival, and connection – a chapter in human history that continues to surprise us with each new discovery.
Ancient Neanderthal Tales
- Neanderthal Down Syndrome Child Revolutionizes Ancient Empathy
- Pain-Sensitive Ancestors: An Ancient Neanderthal Gene Revealed
- Living Together: Modern Humans and Neanderthals Coexisted 45,000 Years Ago
Relics of the Past
- The Neanderthal-modern human genome project has provided valuable insights into the genetic, anatomical, and behavioral differences between Neanderthals and modern humans.
- Key genetic findings include evidence of interbreeding between the two species and the discovery of unique Neanderthal gene variants that contribute to certain traits in present-day humans, such as immune function, skin pigmentation, and disease risk.
- Anatomical differences between the species, such as body proportions and climate adaptations, skull and facial features, and brain structure, have shed light on how they evolved in different environments and adapted socially and technologically.
- Behavioral differences include linguistic abilities, social organization, group size, and level of innovation, which have collectively served as evidence for the adaptive success of modern humans over their Neanderthal forebears.
- Although Neanderthals are thought to have dwindled and eventually disappeared around 30,000 years ago, they are not entirely extinct, living on through the DNA of modern humans outside Africa.
- The study of genetics has revealed that our ancestors intermingled genetically with Neanderthals and Denisovans multiple times, with a significant wave occurring about 50-60,000 years ago, challenging previous beliefs about modern human migration.
- Advancements in technology, such as the IBDmix tool, are enabling researchers to better understand our shared history with species like Neanderthals and Denisovans, challenging stereotypes of Neanderthals as unintelligent and revealing them to be skilled hunters and advanced toolmakers.
