Darwin's Theory

Background

Lindsey Hill The Theory of Evolution Evolutionary concepts appeared in some early Greek writings, e.g., in the works of Thales, Empedocles, Anaximander, and Aristotle. Under the restraining influence of the Church, no evolutionary theories developed during some 15 centuries of the Christian era to challenge the belief in special creation and the literal interpretation of the first part of Genesis; however, much data was accumulated that was to be utilized by later theorists. With the growth of scientific observation and experimentation, there began to appear from about the middle of the 16th cent. glimpses of the theory of evolution that emerged in the mid 19th cent. The invention of the microscope, making possible the study of reproductive cells and the growth of the science of embryology, was a factor in overthrowing hampering theories founded in false ideas of the reproductive process; studies in classification and anatomy, based on dissection, were also influential.In 1859 appeared the first edition of Darwin's Origin of Species. The influence of this evolutionary theory upon scientific thought and experimentation cannot be overestimated. In the years following the promulgation of Darwin's theory of evolution, many accepted and many denied its validity.The theory found an opposing force in some religious creeds that declared it incompatible with their basic tenets. For a time evolution, sometimes falsely interpreted as meaning human descent from monkeys rather than descent from an ancient and extinct ancestor, became a target for attack by both church and educational authorities. Feeling ran high even as late as the time of the Scopes trial.Nevertheless, the theory of evolution became firmly entrenched as a scientific principle, and in most creeds it has been reconciled with religious teachings. Some Christian fundamentalists, however, do not accept the theory and have striven to have biblical creationism taught in the schools as an alternative theory.

Examples

Garrett Shaw Lucy(Australopithecus afarensis) Lucy is a skeleton of a Australopithecus afarensis, a species which has a combination of ape and human-like traits and characteristics. Lucy was found in Hadar, Ethiopia and is thought to be around 3.2 million years old. Lucy supports Darwin's theory of evolution because she is part of a species which is halfway between human and ape, and there are many more slightly different species which slowly start to gain more human traits, Lucy simply got the ball rolling!

Lindsey Hill The Evolution of the Giraffe

Giraffes have changed over time because of the pure need to change.As has been explained by Charles Darwin's Theory of Evolution, animals and people have changed over time because of what we explain as "survival of the fittest". Early giraffes had shorter necks, and they had to reach to get to the food that they found. Due to the torsion that put on their necks, as giraffes mated and had offspring, their offspring's necks got longer and longer. As these giraffes that had longer necks ate all of the leaves that they could reach, they had the same problem their ancestors had, so they kept stretching their necks to reach the uneaten leaves, and as that precess continued through time, the giraffe's neck got progressively longer to the point that they had to bend down to drink water like they do now, because their necks are too long. Whenever people say "Did you know that giraffes have the same number of vertebra in their necks as we do?" it is able to be explained easily. At the beginning, giraffes had short necks, and they had to reach for their food, so their necks got remarkably longer because of their ancestors stretching theirs out, then mating and so on and so forth. Keep that in mind for your next visit to the zoo!

Example

Charles Sampson

One good example of Darwin's idea about survival of the fittest is the evolution of finches, in specific their beaks. This shows a good example of natural selection because all of the finches evolved to be better at one thing or another. For example, finches that live off of a diet of bugs evolved long skinny beaks so that they can dig deep into the ground. This supports natural selection because most finches used to eat seeds but the ones that didn't have thick beaks to crush the seeds had to adapt and be able to eat something other than seeds, such as grubs. Once again, finches that now feed off of tree fruit kept the same thick beak but they evolved a curved point at the end so that they could pick the fruits off of trees. Finches are one of many great examples of Darwin's theories, "Natural Selection" and "Survival of the Fittest"