Final answer:
Human evolution began approximately 7 crore-years ago. Homo sapiens emerged in Africa around 200,000 years ago and expanded out of Africa approximately 100,000 years ago. The 'out of Africa' and 'multiregional evolution' models explain the origins of Homo sapiens.
Step-by-step explanation:
Human evolution began approximately 7 crore-years ago. Evidence suggests that Homo sapiens emerged in Africa around 200,000 years ago. They then expanded out of Africa approximately 100,000 years ago, replacing other human species, according to the 'out of Africa' model. Another model, the 'multiregional evolution model,' suggests that Homo sapiens evolved from Homo erectus in different places at the same time. However, this model is primarily based on fossils and archaeological records rather than genetic data.