A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the airbreathing organ (a simple lung) of an ancestral fish is an example of

In a certain region, children are considered economic benefits. a rising trend in the fertility levels of the region is observed. last year the fertility rate in that region was four children per woman. it is predicted that the fertility rate is going to be six children per woman due to increasing poverty. if the predictions are true then the population of that region will , resulting in