Explain the following population interactions with the help of one example each : (a) Brood Parasitism (b) Co-evolution of mutualists

The correct answer/explanation for the population interactions is:

(a) Brood Parasitism: This is a type of parasitic interaction in which a parasitic bird lays its eggs in the nest of a host bird, leaving the host to incubate and rear its young. During the course of evolution, the eggs of the parasitic bird have evolved to closely resemble the host's eggs in size, color, and pattern, reducing the chances of the host bird detecting the foreign eggs and ejecting them from the nest.
Example: The interaction between the Cuckoo (Koel) and the Crow. The Koel (parasite) lays its eggs in the nest of the Crow (host). The eggs of the Koel resemble the crow's eggs, and the crow hatches and rears the Koel's offspring alongside or instead of its own.

(b) Co-evolution of mutualists: This refers to an evolutionary process where two different species in a mutualistic relationship influence each other's evolution over time. Since both species depend closely on each other for survival or reproduction, any evolutionary change in one species is tightly linked to and prompts a corresponding evolutionary change in the other.
Example: The obligate mutualism between the fig species and its pollinator wasp. A given fig species can be pollinated only by its partner wasp species, and the wasp can lay its eggs only inside the fig fruit. Both species have co-evolved specialized structures and behaviors to maintain this tight partnership.