Final answer:
Neanderthals are considered the closest extinct relatives of Homo sapiens, with interbreeding evidenced by the genetic similarities found particularly in non-African human populations. Fossil records show where Neanderthals lived and how Homo sapiens might have gained an advantage leading to the Neanderthal's demise. This interbreeding contributes to present-day genetic diversity and evolutionary insights.
Step-by-step explanation:
Relationship Between Neanderthals and Homo sapiens
The Neanderthals are considered to be the closest extinct relatives of modern humans (Homo sapiens). The first draft sequence of the Neanderthal genome, published in 2010, revealed that Neanderthals shared a 2 to 3 percent greater genetic similarity with people living outside Africa compared to those within Africa, indicating interbreeding between Neanderthals and Homo sapiens as the latter emerged from Africa. This genetic contribution is present in modern non-African populations today.
Insights from Genetic and Fossil Records
Through genetic research, scientists discovered that Neanderthal DNA intermingled with that of modern humans, suggesting crossbreeding. Fossil records show Neanderthals lived in Europe and Western Asia until about 30,000 years ago, with their DNA now forming a small part of the genetic makeup of modern Eurasian populations. Homo sapiens likely gained an advantage over Neanderthals through factors such as improved technology, language, and immunity to diseases.
Studies suggest that the Denisovan Y chromosome was replaced by Neanderthal interbreeding with early humans. Both Denisovans and Neanderthals are thought to have evolved from Homo heidelbergensis, alongside modern humans. Understanding the exact relationships and interbreeding events continues to be refined with ongoing genetic research and fossil discoveries.
Extinction Hypotheses and Human Evolution
Researchers hypothesize that Neanderthals may have been absorbed into Homo sapiens populations or succumbed to diseases brought by Homo sapiens. Genetic evidence also links Neanderthal ancestry to certain modern health conditions and immunities, showcasing that human evolution is an ongoing process.