In the evolution of man , several change occurred in the ancestral characters . Which one of the following changes is irrelevant in this context ?

Options

A. Loss of tail from body
B. Increase in the ability to communicate with other and develop community behaviour
C. Arboreal mode of lifestyle
D. Perfection in the structure and working of hand for tool-making

Answer

To determine which change in the evolution of man is irrelevant, we will analyze each option provided in the context of ancestral characters and their relevance to human evolution.

### Step-by-Step Solution:

1. **Understanding Human Evolution**:
- Human evolution involves several ancestral characters that have changed over time. Notable stages include Dryopithecus, which existed around 15 million years ago, leading to modern Homo sapiens.

2. **Analyzing the Options**:
- **Option 1: Loss of tail from body**:
- Our ancestors had tails, as they were related to apes. Humans have a vestigial tail represented by the coccyx. This change is relevant as it marks a significant evolutionary adaptation.

- **Option 2: Increase in ability to communicate and develop community behavior**:
- Early ancestors communicated using gestures and simple sounds. Over time, they developed complex speech and community behaviors. This change is relevant as it reflects the evolution of social structures and communication.

- **Option 3: Arboreal mode of lifestyle**:
- Early ancestors lived in trees (arboreal lifestyle). However, as evolution progressed, humans adapted to bipedalism, moving away from tree-dwelling. This change is considered irrelevant in the context of modern human evolution since it reflects an earlier stage that is no longer applicable.

- **Option 4: Perfection in the structure and working of hands for tool making**:
- The evolution of opposable thumbs and refined hand structures has greatly aided in tool making. This change is relevant as it marks a significant advancement in human capability.

3. **Conclusion**:
- After analyzing all options, the irrelevant change in the context of human evolution is **Option 3: Arboreal mode of lifestyle**. This mode is no longer applicable to modern humans, who have adapted to a bipedal lifestyle.

### Final Answer:
The irrelevant change in the evolution of man is **the arboreal mode of lifestyle**.