Fish, amphibians, reptiles, birds, and mammals have similar embryos.

Question

They all start with gill slits. Fish and some amphibians grow to have gills. Some amphibians, reptiles, birds, and mammals develop lungs to breathe air.
They all start with tails. Fish, some amphibians, reptiles, and birds grow tails. Humans do not keep their tails.
Fish and reptiles develop scales. Amphibians, birds, and humans have skin. Birds have feathers, and humans have hair.

Which of the following animals exhibits the most nonlinear relationship as compared to the rest?(1 point)
Responses

amphibians
amphibians

birds
birds

reptiles
reptiles

fish

Answer 1

To determine which animal exhibits the most nonlinear relationship compared to the others based on the shared embryonic characteristics outlined, we need to analyze how these groups develop and diverge from these common traits.

• Fish maintain gills and generally have a straightforward aquatic development.
• Amphibians start with gills and gill slits but transition to lungs (in adults), and their life cycle includes both aquatic and terrestrial aspects, but they still have common traits with fish.
• Reptiles diverge more distinctly after the embryonic stage, maintaining a different set of adaptations such as scales and not transitioning in a manner similar to amphibians.
• Birds also show some distance from amphibians and fish, developing feathers instead of scales or skin but generally retaining some embryonic similarities.
• Mammals (human example) have unique characteristics like hair and are more evolved, lacking tails, which is more divergent.

In this context, amphibians exhibit the most nonlinear relationship as they exhibit both aquatic (like fish) and terrestrial features in their development, suggesting a complex and varied transition that is not as linear as the others. Thus, they represent significant divergence from the embryonic traits shared with fish and reptiles.

So, the answer is amphibians.