Haneen Abouhassoun

We can define a specie as organisms that are able to interbreed successfully and produce  viable  offspring, meaning that their offspring are fertile and can interbreed with other members of the same species. So what happens if a population of a specific species is geographically separated? or if part of the population preferred a specific food, mating behavior, or adaptation while the rest of the population had a different preference even though the two groups are found in the same location?  These ⬆ are examples of how  speciation  may occur. Speciation is when one species diverges into a different specie resulting in two different species that cannot successfully interbreed or produce viable offspring.

 

 

 Phenotypic plasticity is the organisms ability to change any of their phenotypic traits ( such as color or height)in order to adapt to the change in their environment. A scientist could determine weather or not a trait is plastic by changing different conditions in the environment or moving the organism to a completely different environment and observing how that organism may change.  As an example, lets say we have a special species of giraffes, these giraffes are well suited for reaching grass and leafs on short bushes, but lets say for some reason the environment around the giraffes changes and grass and small bushes become scarce. In order for the giraffes to survive their necks elongate just enough so that they are able to reach the leafs on a tree. This would make the length of the giraffes neck a plastic trait.

 Natural selection is based entirely on the external environment of the organism and the more favorable and compatible an organism is with its environment the more natural selection would favor said organism. It does not matter to natural selection if the phenotype is a random mutation or not as long as the phenotype is favored by its environment and is a heritable trait, that certain phenotype will become more and more common in each passing generation until it is the dominant phenotype in the population. This domination is the bases to evolutionary change. a little more simplified explanation: