Convergent Evolution - Examples

Examples

For more details on this topic, see List of examples of convergent evolution.

One of the most well-known examples of convergent evolution is the camera eye of cephalopods (e.g., squid), vertebrates (e.g., mammals) and cnidaria (e.g., box jellies). Their last common ancestor had at most a very simple photoreceptive spot, but a range of processes led to the progressive refinement of this structure to the advanced camera eye — with one subtle difference: The cephalopod eye is "wired" in the opposite direction, with blood and nerve vessels entering from the back of the retina, rather than the front as in vertebrates. The similarity of the structures in other respects, despite the complex nature of the organ, illustrates how there are some biological challenges (vision) that have an optimal solution.

There are also several examples of convergence at level of DNA and protein sequences, including the lysozyme enzyme in monkeys and cows, which have independently evolved foregut fermentation. Similarly, several proteins (including prestin) that are implicated in high frequency hearing in mammals have undergone numerous parallel amino acid replacements in bats and dolphins, both of which have evolved ultrasonic hearing for echolocation.

Read more about this topic:  Convergent Evolution

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