The concept of biological species was given by .......

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the individual who proposed the concept of biological species.

2. **Recall the Concept**: The biological species concept defines a species as a group of individuals that can interbreed and produce fertile offspring.

3. **Understand the Isolation**: According to this concept, members of a species are reproductively isolated from members of other groups, meaning they cannot breed with individuals from different species.

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