13.5 Homo Sapiens and Neanderthal Extinction

Homo Sapiens Migration and Interaction with Neanderthals

• Anatomically modern Homo sapiens:

  • Began migrating out of Africa into the Middle East around 90,000 years ago.

  • Utilized land bridges and coastal routes as environmental conditions shifted.

• Neanderthals:

  • Entered the Middle East later, approximately 60,000 years ago.

  • Adapted to the colder climates and varied landscapes of the region.

• Coexistence:

  • Humans and Neanderthals did not occupy all the same areas simultaneously due to geographical and climatic barriers.

  • Contact between the two species occurred sporadically, influenced by glacial movements, resource availability, and territorial ranges.

• Migration into Europe:

  • Humans migrated from the east into Europe, the primary Neanderthal territory, between 60,000 and 30,000 years ago.

  • Driven by population pressures and environmental changes.

• Last Neanderthals:

  • Lived in southwestern Europe until about 30,000 years ago.

  • Retreated to refugia as Homo sapiens expanded their range.

• Interactions in Southern Europe:

  • Homo sapiens and Neanderthals coexisted in Southern Europe for at least 10,000 years.

  • Interactions included competition for resources, cultural exchange, and interbreeding.

The Extinction of Neanderthals

• Cause of extinction:

  • A major unresolved question involving multiple interacting factors.

• Coexistence in Europe:

  • Both Neanderthals and Homo sapiens inhabited Europe around 90,000 years ago.

  • Experienced similar environmental challenges and occupying overlapping ecological niches.

• Initial theories:

  • Suggested conflict or competition between the species.

  • Early mitochondrial DNA analysis indicated no interbreeding, supporting the replacement hypothesis.

• Competition hypothesis:

  • Homo sapiens may have killed off Neanderthals or outcompeted them for resources.

  • Superior hunting techniques, social organization, or adaptability.

• Impact of low temperatures:

  • More recent evidence points to extremely low temperatures in Europe decimating both Neanderthal and Homo sapiens populations between 40,000 and 30,000 years ago.

  • Created demographic bottlenecks.

• Repopulation of Europe:

  • Homo sapiens populations in the Middle East and Africa were able to repopulate Europe as glaciers receded due to larger populations and established networks.

  • Neanderthals, lacking an external population source, could not recover, leading to their eventual extinction.

Evolution and Distribution

• Late Homo erectus:

  • Survived for an extended period, demonstrating resilience and adaptability to various environments.

• Heidelbergensis:

  • Many examples also survived, evolving regional adaptations and contributing to the genetic diversity of later hominids.

• Neanderthal evolution:

  • Believed to be a group of Heidelbergensis isolated in Europe during a glaciation event.

  • Underwent genetic drift and developing unique physical characteristics.

• Homo sapiens evolution:

  • In Africa, Heidelbergensis evolved into anatomically modern Homo sapiens.

  • Characterized by advanced cognitive abilities and complex social structures.

• Neanderthal distribution:

  • Primarily found in Europe and parts of the Middle East.

  • Adapted to colder climates and specific ecological niches.

• Homo sapiens distribution:

  • The earliest fossils are found in Africa and the Near Middle East.

  • Subsequent spread across the world, facilitated by technological innovations and social cooperation.

• Herto fossil:

  • A Homo sapiens fossil from Herto, East Africa, dating back 60,000 years.

  • A clear example of an anatomically modern human, exhibiting key skeletal features and cranial capacity.

Upper Paleolithic Tool Technology

• Development:

  • Homo sapiens developed a new tool technology known as the Upper Paleolithic, an advancement over the Mousterian technology.

  • Used by Neanderthals and earlier hominids.

• Features:

  • Greater variety and specialization of tools made from various materials, including stone, bone, ivory, and antler.

• Examples:

  • Bone needles for sewing clothes.

  • Scrapers for preparing hides.

  • Potential harpoons for fishing, indicating a broad range of subsistence strategies.

• Specialization:

  • Suggests that Homo sapiens were targeting different types of prey.

  • Optimizing resource utilization and adapting to diverse environments.

• Megafaunal extinctions:

  • Some researchers speculate that Homo sapiens may have contributed to megafaunal extinctions.

  • Efficient hunting techniques and increased population density.

• Tool characteristics:

  • Exhibit more diversity, standardization, and special-purpose designs compared to previous technologies.

  • Reflecting advanced cognitive abilities and cultural transmission.

• Implications:

  • Imply foresight, training, and the ability to think ahead about specific tasks.

  • Indicating sophisticated planning and problem-solving skills.

• Comparison to Acheulean hand axe:

  • Upper Paleolithic tools were designed for specific functions, demonstrating a shift towards specialized technologies and increased efficiency.

  • Unlike the Acheulean hand axe used for multiple purposes.

Upper Paleolithic Culture and Art

• Flourishing:

  • Upper Paleolithic culture flourished after the disappearance of Neanderthals.

  • Marked by significant advancements in art, symbolism, and social complexity.

• Cave art:

  • Including representations and carvings of animals became prevalent.

  • Reflecting a rich symbolic culture and advanced cognitive abilities.

• Depictions:

  • Drawings depict real animals of the time, not fantastical creatures.

  • Providing valuable insights into the environment and fauna of the Upper Paleolithic.

• Purpose:

  • Unknown, but it may indicate symbolic thinking, language abilities, ritual practices, or a combination thereof.

• Artifacts:

  • Representational artifacts from this period have also been found in South Africa and Australia.

  • Indicating widespread cultural and artistic expression among early Homo sapiens populations.

• Preservation:

  • Cave art in Europe is well-preserved due to the sheltered environment of caves.

  • Offering a unique window into the cultural and cognitive lives of Upper Paleolithic humans.

• Rock paintings in Australia:

  • Dating back 60,000 years, providing evidence of early artistic traditions and cultural practices in the region.

• Ochre in South Africa:

  • Dating back approximately 75,000 years show geometric patterns.

  • Suggesting early symbolic behavior and abstract thinking.

• Independent discovery:

  • The rock art in Australia appears to be an independent discovery of art.

  • Highlighting the parallel development of cultural traditions in different parts of the world.

• Preservation biases:

  • May influence the distribution of cave paintings, with better preservation in European caves due to favorable environmental conditions.

• Interspecies influences:

  • Interactions between Homo sapiens and Neanderthals may have influenced cave painting as a means of communication or marking territory.

  • Reflecting cultural exchange and interspecies interactions.

Expansion and Interbreeding

• Global migration:

  • Homo sapiens migrated out of Africa and spread across the globe, reaching Australia by about 70,000 years ago.

  • Adapting to diverse environments and establishing new cultural traditions.

• Early fossils:

  • The earliest Homo sapiens fossils date back approximately 80,000 years in Africa.

  • Providing crucial evidence for the origins and early evolution of modern humans.

• Presence in Middle East, Asia, and Europe:

  • By 50,000 years ago, they were present in the Middle East and Central Asia, and by 60,000 to 50,000 years ago, they were in Europe, interacting with Neanderthals.

  • Leading to complex social and genetic interactions.

• Neanderthal interaction:

  • Whether Neanderthals were replaced, outcompeted, or interbred with Homo sapiens is still under investigation.

  • With evidence supporting multiple scenarios depending on the region and context.

• Interbreeding evidence:

  • Evidence from nuclear DNA suggests interbreeding between Neanderthals and Homo sapiens occurred.

  • Resulting in a small percentage of Neanderthal DNA in modern human populations of non-African descent.

• Genetic assimilation:

  • The larger Homo sapiens population may have diluted distinct Neanderthal traits through interbreeding.

  • Contributing to the genetic assimilation of Neanderthals into the Homo sapiens gene pool.

Migration to the Americas

• Last continents populated:

  • The Americas were among the last continents populated by hominids.

  • Representing a significant milestone in human migration and adaptation.

• Bering Strait theory:

  • An outdated theory suggests a migration around 13,000 years ago via the Bering Strait.

  • Coinciding with the end of the last Ice Age and the opening of ice-free corridors.

• Coastal route theory:

  • An alternative theory proposes earlier migration, possibly around 30,000 years ago, via a sea route following the coastline from Asia to the west coast of North America.

  • Requiring advanced maritime skills and technologies.

• Earlier arrival evidence:

  • Evidence suggests humans arrived in North America much earlier than 13,000 years ago.

  • With archaeological sites and genetic studies supporting the presence of human populations tens of thousands of years ago.