Gradualism & Punctuated Equilibrium
Gradualism is selection and variation that happens more gradually, over a short period of time it is hard to notice.
In punctuated equilibrium, change comes in spurts. There is a period of very little change, and then one or a few huge changes occur, often through mutations in the genes of a few individuals.
Natural selection is the process by which species adapt to their environment.
Natural selection leads to evolutionary change when individuals with certain characteristics have a greater survival or reproductive rate than other individuals in a population and pass on these inheritable genetic characteristics to their offspring.
Passing of traits from parents to offspring by means of genes.
However, if this genetic copying were always perfect, children would be exactly like their parents, and we would not see the tremendous amount of variety that we do in populations in the real world. So along with a mechanism for heredity, there must also be some procedures that allow for small changes to happen in order to create variation. One such procedure is the 'copying error' ; these errors, known as mutations.
Survival of the Fittest
The idea that species adapt and change by natural selection with the best suited mutations becoming dominant.
Difference in reproductive success that involves both the ability to survive until reproductive age and then the capacity to reproduce.
“We have seen that man bears in his bodily structure clear traces of his descent from some lower forms. But it may be urged that as man differs so greatly in his mental power from all other animals, there must be some error in this conclusion. My object is to show that there is no fundamental difference between man and the higher mammals in their mental faculties. Animals possess the power of reasoning just as much as man do” -Darwin in his The Descent of Man