Which of the following is an example of convergent evolution? (DOK 1)
a. Similar amino acid sequences in humans and chimpanzees
b. Similar bones in the forelimbs of horses and bats
C. Similar body shape in dolphins (mammals) and fish
d. Different beak shapes of the Galapagos finches
The Correct Answer and Explanation is :
The correct answer is c. Similar body shape in dolphins (mammals) and fish.
Explanation:
Convergent evolution occurs when different species independently evolve similar traits, even though they do not share a recent common ancestor. This typically happens when organisms face similar environmental pressures and natural selection favors similar adaptations. Let’s look at the options in detail:
- a. Similar amino acid sequences in humans and chimpanzees: This example illustrates homologous structures, which are traits shared by species due to common ancestry. Humans and chimpanzees share a common ancestor, and their genetic similarities are a result of inherited traits, not convergent evolution.
- b. Similar bones in the forelimbs of horses and bats: This is an example of homologous structures too. Both horses and bats have forelimbs with similar bone structures because they evolved from a common vertebrate ancestor. This is divergent evolution, not convergent evolution.
- c. Similar body shape in dolphins (mammals) and fish: This is a classic example of convergent evolution. Dolphins are mammals, while fish are a completely different group of animals. However, both have evolved streamlined bodies suited for efficient swimming in aquatic environments. This shape is not inherited from a common ancestor but rather is an adaptation to similar environmental pressures—living in water and moving efficiently through it. The similarity in body shape is an outcome of convergent evolution.
- d. Different beak shapes of the Galapagos finches: This is an example of divergent evolution, where different beak shapes evolved in finches based on the availability of different food sources on the Galapagos Islands. These finches have a common ancestor, and the variations in beak shapes are adaptations to different ecological niches.
In summary, convergent evolution results in unrelated species developing similar traits due to similar selective pressures, as seen in the body shape of dolphins and fish.