Question

The presence of temporary gills in the embryos of snakes, birds and man indicates that

• A. These embryos need gills for breathing.
• B. Ancestors of these animals had gills at one stage of evolution.
• C. Lungs evolved from gills.
• D. None of the above.

Answer 1

Answer: (B)

Ancestors of these animals had gills at one stage of evolution.

As per the biogenetic law, an organism during embryo development passes through the same stages as during its evolution. Presence of temporary gills in embryo of these terrestrial organisms show that their ancestor were living in aquatic habitat and had gills.

So, the correct answer is 'Ancestors of these animals had gills at one stage of evolution'