EVERYDAY SCIENCE

Detailed explanation-1: -In a finch population, if finches having large beaks and finches having small beaks increase in numbers while finches with average beaks decreases is directional selection.

Detailed explanation-2: -Finches on Santa Cruz Island On Santa Cruz Island, disruptive selection was seen causing speciation in the population of finches that resides there. Due to forces of disruptive selection, intermediate beak sizes have been selected against for generations. The resulting population has almost no medium sized beaks.

Detailed explanation-3: -In other words, beaks changed as the birds developed different tastes for fruits, seeds, or insects picked from the ground or cacti. Long, pointed beaks made some of them more fit for picking seeds out of cactus fruits. Shorter, stouter beaks served best for eating seeds found on the ground.

Detailed explanation-4: -Diversifying or disruptive selection increases genetic variance when natural selection selects for two or more extreme phenotypes that each have specific advantages.