What do you mean by recapitulation theory ? Who proposed it ?

Explanation

### Step-by-Step Text Solution

1. **Definition of Recapitulation Theory**: Recapitulation theory, also known as the Biogenetic Law, is a biological hypothesis that suggests that the development of an individual organism (ontogeny) follows the same progression as the evolutionary history of that organism's species (phylogeny).

2. **Proposer of the Theory**: This theory was proposed by the German zoologist Ernest Haeckel in the year 1866.

3. **Key Concept**: Haeckel's law states that the developmental stages of an organism reflect the adult forms of its evolutionary ancestors. In simpler terms, the embryonic development of an organism will exhibit features that resemble the adult forms of its ancestors.

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