Final answer:
Homo sapiens evolved from Homo erectus in Africa, with Homo habilis as a possible ancestor. Homo erectus had a larger brain and more modern human features than predecessors. Continuous research in paleoanthropology and genetics enhances our understanding of human evolution.
Step-by-step explanation:
Evolution of Homo sapiens
The species Homo sapiens evolved from earlier hominins in Africa, with the most widely accepted ancestor being Homo erectus. Homo erectus, which means 'upright man', evolved in East Africa around 1.9 million years ago and displayed a number of features more akin to modern humans. This species had a brain capacity larger than its predecessors, with a cranium that could hold about 1,400 cubic centimeters. They were characterized by less pronounced brow ridges, a roughly modern stature, and smaller teeth compared to earlier hominins.
One important predecessor to Homo sapiens was Homo habilis, known as the 'handy man', which lived from about 2.5 to 1.4 million years ago and is suspected to be ancestral to Homo erectus. Homo habilis exhibited both australopithecine and Homo traits, with a larger brain at 600 to 750 cubic centimeters and a jaw less protruding than that of australopiths, yet retaining the long arms characteristic of earlier hominins.
Another related group was the genus Australopithecus, a potential precursor to the genus Homo, which thrived in eastern Africa and turned extinct about two million years ago. Although not directly ancestral to Homo sapiens, they represent an important stage in human evolution with their upright walking. Homo sapiens themselves emerged in Africa around 200,000 years ago with developments such as a steep forehead, a well-rounded skull, and a capacity for language and complex tools, which distinguished them from their hominin relatives.
The relationship between Homo sapiens and other species in the genus Homo and their evolutionary pathways are augmented by continuous paleoanthropological and genetic research. This research informs theories like the 'Out of Africa' model and the 'multiregional evolution model', the latter considering the possibility of Homo sapiens evolving simultaneously in multiple regions from local populations of Homo erectus.