Question

Which of the following statements is/are related to the contribution of Karl Ernst von Baer?

• A. Embryo of a higher animal never resembles the adult stages of other animals
• B. Comparative anatomy shows differences among organisms of today and those that existed years ago
• C. All features during embryonic stages are common to all vertebrates that are absent in adults
• D. Ontogeny repeats phylogeny

Answer 1

The correct option is A Embryo of a higher animal never resembles the adult stages of other animals

The Biogenetic law or Recapitulation theory was given by Ernst Haeckel in 1866. It states that ontogeny (embryonic developmental history) recapitulates phylogeny (evolutionary history). This means that higher animals in their embryonic development pass through stages similar to the adult stages of lower ones.

This theory was in contradiction to what was proposed by Karl Ernst von Baer. He stated that embryos never pass through stages resembling the adult stages of other animals. Instead, the common and general characteristics appear first which are followed by the development of special characteristics. For example: The embryonic development in humans never resembles any stages of lower animals like chicken or fish, instead the embryonic development of human, chicken and fish follows some similarities which later diverge from each other to develop special characters.