🌿 Humans in Nature: Human Evolution
Understanding our place in the tree of life and the journey of our species
🔬 What Is Human Evolution?
Human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people evolved over a period of approximately six million years.
📖 Key Term: Paleoanthropology is the scientific study of human evolution. It is a subfield of anthropology — the study of human culture, society, and biology.
Humans are primates. Physical and genetic similarities show that our species, Homo sapiens, has a very close relationship to the great apes. In fact, chimpanzees and humans share DNA sequences that differ by only about 1%!
⚠️ Common Misconception: "Humans evolved from chimpanzees." This is incorrect. Humans did not descend from modern chimpanzees. Instead, humans and chimps share a common ancestor that lived roughly 6–8 million years ago.
🧬 DNA Similarity Between Species
Interactive visualization — available in the full lesson
⏳ Timeline of Human Evolution
The story of human evolution stretches back millions of years. Here are the key milestones:
🦴 Bipedalism — the ability to walk upright on two legs — was one of the earliest defining human traits, evolving over 4 million years ago. This freed the hands for tool use!
🧠 Brain Expansion — Cranial capacity grew from ~400–550 cm³ in early hominins to ~1,300–1,400 cm³ in modern humans — roughly a threefold increase!