Final answer:
Neanderthals and AMHS were sympatric in Europe for approximately 2,600 to 5,400 years, sharing the same regions until Neanderthals began to decline around 40,000 years ago, influenced by factors like environmental changes and competition with AMHS.
Step-by-step explanation:
Duration of Neanderthals and AMHS Sympatry in Europe
Neanderthals and Anatomically Modern Humans (AMHS) were sympatric, meaning they coexisted in the same regions, for a period in Europe. Based on archaeological and genetic evidence, this sympatry lasted for approximately 2,600 to 5,400 years. Neanderthals, who evolved from Homo erectus, lived in Europe and parts of western Asia between 400,000 and 40,000 years ago, and AMHS began to spread into Europe around 50,000 years ago. The evidence indicates that the two groups not only shared the same area but also interacted and interbred with each other to some extent. The Neanderthals started to decline around 40,000 years ago, and their disappearance from the fossil record aligns with the time by which AMHS had become more widespread across various regions. Factors contributing to the Neanderthal's extinction include environmental changes, competition for resources with AMHS, and potential impacts of low genetic diversity and birth rates.