Step 1: Understanding the Concept:
Human evolution is characterized by increasing brain size (cranial capacity) and changes in posture and tool usage over millions of years.
Step 2: Detailed Explanation:
1. {Australopithecus:} Lived about 2 million years ago in East African grasslands. They were the ancestors to the Homo genus.
2. {Homo habilis:} The "handy man," the first human-like hominid. Brain capacity 650-800 cc.
3. {Homo erectus:} Lived about 1.5 million years ago. Had a larger brain (900 cc) and walked upright.
4. {Homo sapiens:} Modern humans, arose in Africa and moved across continents about 75,000-10,000 years ago.
Step 3: Final Answer:
The chronological order is Australopithecus $\rightarrow$ Homo habilis $\rightarrow$ Homo erectus $\rightarrow$ Homo sapiens.