Question

Which of the following are good examples for co-evolution?

[mark all correct answers]

a.Climate change causes birds in Europe and Africa to start breeding earlier in the season

b.viruses evolving receptors that fit hosts' cell surface molecules

c.Pandas evolving a "thumb" from their wrist bone that helps them strip leaves off bamboo stalks.

d.flowers evolving longer and longer spurs to contain nectar and butterflies evolving longer and longer tongues to reach the nectar

e.Phagocytes produce enzymes to digest viruses and Mycobacterium tuberculosis resists digestion in phagocytes

Answer 1

Solution

Good examples for co-evolution

b.Viruses evolving receptors that fit hosts' cell surface molecules- is an example for co-evolution because viruses are evolving mechanisms to counteract host defense mechanisms

d. Flowers evolving longer and longer spurs to contain nectar and butterflies evolving longer and longer tongues to reach the nectar because in this example, when flower evolves with longer and longer spurs to contain nectar simultaneously the butterflies evolve with longer and longer tongues to reach the nectar

Co-evolution is the process of joint evolution of two (or more) ecologically interacting species, each of which evolves in response to selection imposed by the other. It also refers to the evolution of one species caused by its interaction with another, or it is a joint divergence of ecologically associated species.

Explanation for wrong options

a. Climate change causes birds in Europe and Africa to start breeding earlier in the season- Even though, climate change is a common factor that influence the species to evolve to start breeding earlier in the season, no species interaction occurs here. Remember that co-evolution occurs between ecologically interacting species

c. Pandas evolving a "thumb" from their wrist bone that helps them strip leaves off bamboo stalks. This is not an example for co-evolution because, evolution of a special "sixth digit allows giant pandas to grasp bamboo shoots. However, in this case the bamboo do not evolve simultaneously

e.Phagocytes produce enzymes to digest viruses and Mycobacterium tuberculosis resists digestion in phagocytes- This is not an example for co-evolution because here phagocytes are producing enzymes to digest viruses, and the virus is not evolving any defense mechanism to defend the host. It is Mycobacterium tuberculosis that resist the digestion in phagocytes. Remember co-evolution is the process of joint evolution of two (or more) ecologically interacting species