When did hominins (the human lineage) diverge from the lineage that produced modern chimpanzees? A. 120,000 years ago B. 200,000 years ago C. 5.5-6.5 million years ago D. 55 million years ago
The correct answer and explanation is:
The correct answer is C. 5.5-6.5 million years ago.
Hominins, the group that includes modern humans and our immediate ancestors, diverged from the lineage that led to modern chimpanzees roughly 5.5 to 6.5 million years ago. This divergence marks one of the most significant events in evolutionary history. Both humans and chimpanzees share a common ancestor, which was a species of primate that lived millions of years ago. Over time, this common ancestor evolved differently, leading to the distinct evolutionary paths that produced the modern human species and the modern chimpanzee.
The exact timing of the split is based on molecular data, including genetic comparisons between humans and chimpanzees, as well as fossil evidence. Fossils of early hominins, such as Sahelanthropus tchadensis, which lived around 7 million years ago, provide key evidence for the early stages of human evolution. These fossils show a mixture of characteristics from both chimpanzees and humans, indicating a common ancestor from which both lineages evolved.
The divergence also involved changes in brain size, bipedalism (walking on two legs), and other physiological and behavioral traits. Chimpanzees and humans are both part of the family Hominidae, but their paths diverged after this common ancestor. Over millions of years, early hominins began to exhibit more human-like traits, eventually leading to the emergence of Homo sapiens around 300,000 years ago.
In summary, the split between the human and chimpanzee lineages occurred about 5.5 to 6.5 million years ago, marking a critical point in the history of human evolution.