Evolution is a gradual process that results in change of the genetic makeup of a population over time. According to evolutionary change there are two general classes of evolution which include; microevolution and macroevolution. Microevolution is a process that involves the change in allele frequency in a certain population over a period of time while macroevolution is the change at or above level of species.
Natural selection is a basic mechanism of evolution which states that evolutionary change occurs through the production or variation in each generation and the differential survival of the individuals that have different forms of these variable traits. This means that individual with favorable traits that increases their chances of living or survival have a higher probability to reproduce and their offspring will benefit from the traits compared to those with decreased chances of survival and their off springs do not benefit therefore individuals with higher chances of survival over time will spread through the population.
Inheritance is a mechanism of evolution that was first developed by Lamarck; this theory explains how the genes from the parent are passed to the off springs over time. It explains the change in inheritance or transfer of characteristics from one population to another through successive generations. Living organisms reproduce and their off springs inherit their characteristics. Acquired genes from the parent are passed on to the off springs and the successive generations.. Lamarck gave an example of long necks in giraffe. Long time all giraffes had short necks but as food supply decreased, giraffes had to stretch their necks to reach leaves in tall trees and as a result giraffe’s neck grew tall and thus their off springs and later generation acquired this trait which helped them to survive. For example initially all mammals were one but due to continental drift two types of mammal emerged; placental mammals and pouched mammals. Placental mammals completed their gestation period in the womb while pouched mammals completed their gestation period inside nutrient providing pouch. With time these characteristics have