History of Evolution

Abstract

Evolution is a change in the characteristics of a population from generation to generation. Evolution occurs via natural selection which creates competition between organisms to survive. Although, people have been thinking about evolution for years, Charles Darwin is often referred to as the father of evolution. The theory of evolution is also a topic of great debate because some parts of the theory contradict people's religious beliefs.

Introduction

Since Charles Darwin published The Origin of Species in 1859, the topic of evolution has been up for debate for quite sometime now. Do species go extinct? Do humans and primates share a common ancestor? Do traits acquired over the life time of an organism, pass down to the offspring? Should evolution be taught in the classroom? These are all questions that have been asked pertaining to evolution. Evolution is a racy topic because it pits the field of science against people fundament religious beliefs.

Ideas before Darwin

Biological evolution can be defined as a change in the form or the behavior of an organism between generations. Although, the concept of biological evolution has been around for quite some time, it's roots can be traced back to the times of ancient Greek and Roman empires with the great philosopher Aristotle. Aristotle came up with the idea which he called, "The Great Chain of Being." In his view Aristotle believed the world to be a perfect universe, in which species could never evolve and must remain fixed. Aristotle came up with the idea which he called, "The Great Chain of Being," which was his attempt to make sense of the changing relationships among living beings. In this view Aristotle believed the world to be a perfect universe, in which species could never evolve and must remain fixed. There was an order to beings or ladder, with species such as worms on the bottom and human beings at the top of the ladder. Aristotle was also well-known of his work in the field of biology where he was able to classify more than five hundred types of species. Among the work of Aristotle is a writing that foreshadows the idea of natural selection, he states,"Wheresover, therefore...all part of one whole happened like propriately constituted by an internal spontaneity; and wheresover things were not thus constituted they perished, and still perish" (Avery, 2003). Also at this time religion played a major role in peoples lives and applied the religious beliefs to all aspects of their lives. The Judeo-Christian culture believed that the Earth was only about 6,000 years old, an idea that could be traced back to biblical documents. Although, many people believe that the idea of evolution goes against their personal religious beliefs many naturalists and philosophers still struggle to understand the concept of evolution.

The next idea in the theory of evolution came from Jean-Baptiste Lamarck. Lamarck wrote Zoological Philosophy, in which he stated that lineages of species persist indefinitely, changing from one species to another. Lamarck came up with two mechanisms for his theory of evolution which are "Internal Force" and "Inheritance of acquired characters". In his "Internal Force" mechanism he states that there is that some unknown mechanism causes organisms to produce offspring that are slightly different from the parents. Lamarck's second mechanism states that all characters that an organism acquires over its lifetime are passed down to their offspring. For example, Lamarck believed that long neck giraffes evolved due to the fact that each giraffe would stretch its neck to reach the leaves in high trees and after generations and generations the trait was continually passed down and created two different, distinct species. (Ridley, 2004)

Darwin's Theory

A new view of evolution began to form in 1832 when Darwin boarded the H.M.S. Beagle. The year of 1835 brought Darwin to the Galapagos Islands where his revolutionary theory came to life. "Darwin thought evolution moved so slowly that changes in progress could not be seen until significant amounts of time passed" (Weiner 2005). Darwin's theory contradicted many creationists' theory, one of them being the world was only six thousand years old. His theory evolving organisms over time contradicted the creationist theory at the time. "Creationist theory prevailing at the time interpreted the exquisite adaptation of many species as evidence that God created each species for its intended niche in the natural environment" (Sulloway, 2005). After his voyage ended in 1837 Darwin began to think of a mechanism for evolution, which became natural selection. Nature selection is defined as "the process by which the forms of organisms in a population that are best adapted to the environment increase in frequency relative to less well adapted forms over a number of generations"(Ridley, 2004). Darwin's mechanisms of natural selection shows how organisms adapt to their environment pass on the traits favorable to their offspring and create an ancestral lineage between different species by means of a common ancestor through extinction. In other words, Natural Selection is the evolutionary process that states favorable traits are inherited and therefore become more common in future generations of the specific species. In his work The Origin of Species Darwin states, "Actions of Natural Selection, through Divergence of Character and Extinction, on the descendants from a common parent--Explains the Grouping of all organic beings" (Darwin, 1859). Darwin's mechanism of natural selection put organisms in a struggle for existence, with the organisms that adapt the best surviving. Michael Ruse stated, "Although Darwin always regarded natural selection as his primary mechanism of evolutionary change, it was never his sole mechanism. Also, Darwin posited that there is a second kind of selection. Natural selection involves a straight struggle for existence and reproduction" (Ruse 1983). The other type of selection described in The Origin of Species is sexual selection, which is a selection on mating behavior, through competition between members of the same sex to reproduce. Ruse states, "Darwin identified two forms of this selection, which he called 'sexual selection.' The first form is triggered when the males of a group fight for the females, and the second occurs when females choose the most attractive males" (Ruse 1983). Originally, after his publishing of The Origin of Species Darwin's theory of evolution was widely accepted by the best scientific minds of the time, but widely rejected