Which one of the following ancestors of man first time showed bipedal movement?

Options

A. Cro-Magnon
B. Australopithecus
C. Java ape man
D. Peking man

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which ancestor of man first exhibited bipedal movement. Bipedal movement refers to walking on two feet, which is a characteristic of modern humans.

2. **Identifying the Options**: The options provided are:
- Cro-Magnon
- Australopithecus
- Java Ape man
- Peking man

3. **Analyzing Each Option**:
- **Cro-Magnon**: This is a term used for early modern humans, who were already fully bipedal.
- **Java Ape Man**: Refers to early hominids, but evidence does not strongly support that they were the first to walk bipedally.
- **Peking Man**: Another early human ancestor, but again, not the first to show bipedalism.
- **Australopithecus**: Fossils of Australopithecus date back to approximately 4.2 to 3.9 million years ago and show clear adaptations for bipedal locomotion, such as changes in the structure of the thighs, hips, and spinal cord.

4. **Conclusion**: Based on the analysis, Australopithecus is the ancestor that first showed bipedal movement.

5. **Final Answer**: Australopithecus.

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