Example of co-evolution
Select the example of co-evolution from the following choices.
A) Humans make digestive enzymes that enable us to eat both plants and animals.
B) Tapeworms attach in an animal's digestive system and take nutrients from it.
C) Mountain lions can run faster than the animals they hunt.
D) Orchid flowers produce nectar that feeds the bees that pollinate them.
Coevolution is where two species affect eachother's evolution. The best answer here is choice B. Tapeworms have coevolved along with their host, which is always another animal. The host can be a vertebrate, such as a human. The tapeworms lack digestive organs and actually absorb the nutrients they need from the host's intestine, where they are attached with their scolex. It contains suckers and hooks--both are adaptations to help the tapeworm survive. Through coevolution, they lost their digestive system and simply absorb the host's nutrients through their body wall. Actually, choice D is also a type of coevolution. Orchids and their insect pollinators have coevolved because sometimes the flower secretes a pheromone that attracts the insect pollinator to carry pollen to another orchid.