What was the prevailing theory on the origin of the new species before Darwin formulated his theory?
In the past, people used to believe that species were not connected in a single family tree. Also, the accepted notion that the Earth was no more than 6000 years old led people to assume that evolution could not possibly be taking place. The world was viewed as stable and unchanging and thus, the idea that evolution took place was not commonly accepted. Furthermore, people were not considered to be part of the natural world and thus few would have believed that people could actually have evolved from apes or any other animals. Evolution was considered an impossible theory.
The existing theory on the origin of the new species before Darwin formulated his theory was Jean-Baptiste Lemarck’s theory on all animals having the same ancestral. Lemarck’s theory is that all animals evolved to suit their environment and this evolved characteristic is passed on to the following generations. In example, according the Lemarckian theory, giraffes stretch their necks to reach the leaves on the top of the trees, as these leaves are fresher than the leaves on the bottom half of the trees. As the giraffes’ necks grew longer to adapt to their environment, this trait is further passed on to future generations through inheritance. Another example can be a man who is very muscular through training and physical exercise is predicted to have offsprings who have a lot of muscles. In summary, the Lamarckian theory suggests that a change in the environment will cause a change in character traits and these desirable characteristics will be passed on to the future generations so that they can adapt to the environment.
Did anyone have theories similar to Darwin’s?
Alfred Russel Wallace, a British naturalist and biologist, had theories similar to Darwin’s. He proposed a theory on natural selection independently and tested the hypothesis on the reality of evolution. His theory was that the causes of species evolving are due to the destruction causes are huge enough to keep the numbers of each species down to prevent them from increasing enormously each year. To prevent overcrowding, only the best fitted in the environment live. Organisms adapt to changes of the environment and in the process, the animals that are unmodified will slowly die out, with only the fittest surviving. These species with more desirable characteristics then produced more off springs. Also, the species with less desirable will slowly die out, causing only the survival of the fittest. One example can be the finches. The different environmental conditions encourage the same species of finches to adapt to their own environment. In the long run, the traits of the beaks descend with modification, as there is competition for survival. Hence, the particular trait that they have will enable them to adapt to the environment better than those without. Hence, they have a reproductive advantage and have a higher chance of having more offspring.
This is similar to Darwin’s theory that favourable characteristics, which are heritable, become more common in following generations of a population. Some species are able to adapt to their environment better than others and thus more likely to survive and breed than some of their competitors. As such, the characteristic they possess will become more common in future generations.
What role did religion play in regard to people’s beliefs concerning the origin of life on earth?
There are 19 different main religions, which are further split into a total of 270 large religious groups, and many thousands of smaller ones. Religion played an important role in regard to people’s viewpoints about the origin of life on earth. There are hundreds of considerably different creation stories to draw from. For example, the New Earth and Old Earth creationists’ beliefs influence people to believe that evolution is not possible. New Earth creationists believe that no new species have been created since creation and only minor changes occur within some species. Old Earth creationists believed in the creation of Earth, its life forms and the universe at the same time by God. Another reason why people did not accept the theory behind evolution was because of the Bible. Few people questioned the Bible and people believed that God created human to rule over animals. As such, the thought that people actually evolved from human was against their religion, and people were less willing to accept the theory. When the people finally accepted the theory of evolution, many of them still viewed it as a tool created by God to accomplish the creation of humans. Therefore, religion played an important role in slowing the process of people believing in the theory of evolution.
Sources:
Evolution Revolution
http://www.pbs.org/wgbh/evolution/religion/revolution/index.html
A History of Evolutionary Thought
http://www.ucmp.berkeley.edu/history/evothought.html
Wikipedia
http://en.wikipedia.org/wiki/History_of_evolutionary_thought
Picture of Giraffe
http://img.sparknotes.com/figures/1/1534327ece5d347f8fe2828c8fdb7677/giraffe.gif
Picture of Bible
http://catholicfaithandreason.org/Faith&Reason-2.jpg
Picture of Finches
www.hras.org/sw/swnov04a.jpg
Darwin: A Very Short Introduction
Oxford University Press – by John Howard