Question

Dolphins and fish have similar body shapes. Is this feature more likely a homologous or analogous trait?

a) Homologous, as it indicates a shared evolutionary ancestry.
b) Analogous, as it suggests adaptation to a similar environment.
c) Neither homologous nor analogous.
d) Both homologous and analogous.

Answer 1

Dolphins and fish have similar body shapes due to analogous traits, indicating adaptations to an aquatic environment through convergent evolution, rather than homologous traits that would suggest a shared evolutionary history.

Step-by-step explanation:

Dolphins and fish have similar body shapes, which represents a fascinating example of how organisms can evolve to have similar traits due to environmental pressures. This characteristic is analogous, as it suggests adaptation to a similar environment, rather than indicating shared evolutionary ancestry. The streamlined and torpedo-like shape of both dolphins and fish is a result of convergent evolution, where unrelated species independently evolve similar traits as a response to similar environments or ecological niches.

It's important to differentiate between homologous and analogous traits. Homologous traits share a similar embryonic origin or evolutionary path. In contrast, analogous traits are the result of separate lineages responding in similar ways to environmental challenges. Since dolphins are mammals and have a different evolutionary path from fish, which are part of the aquatic vertebrates, their similar body shapes are not due to a shared recent evolutionary history but to the requirements of moving efficiently through water.