1. The individual I chose to be a positive influence on Charles Darwin is Thomas Malthus. While Darwin had his theory about natural selection and the evolution of species, he was not certain how the new species developed. It was only after Darwin read the "An Essay on the Principle of Population" by Thomas Malthus that he realized how species came to be. Malthus stated that the population of a species grows faster than its resources, which was in line with his theory of "struggle for existence". Said competition is a key component in comprehending the concept of natural selection. While this was not an option I believe a non-human influence on Darwin was his travel on the HMS Beagle to South America. This travel set in motion his ability to be influenced by Lyell and Malthus as he had been able to witness the geographical and physical adaptations he learned about much later.
2. According to the online publication of 2007 by Matt Rosenberg at
http://geography.about.com/od/populationgeography/a/malthus.htm Malthus stated in his essay that the human population grows at a faster rate than the resources it depends on to provide for. His main argument is the supply of food and water, which according to his study of the population of America at the time was doubling while the production of food went at a much slower rate. He stated that overpopulation would lead to starvation. To prevent this he factored in conditions, such as abstinence, homosexuality and birth control. From his scientific views he had to include those findings, even though his religious believes condemned the later two. Lastly he opposed welfare, as this would encourage the poor, who do not have enough resources to begin with, to procreate. His objective was to have them realize that the more children they have the more of them would starve. He continued to study and alter his essay and published the 6th and final edition in 1826.
3.
a) all organisms have the potential of reproducing exponentially
While this is correct, reproduction takes a toll on any female body. A malnourished female will not be able to carry a pregnancy full term, have a malnourished child or might have a still birth.
b) Resources are limited
Even if the off spring survives, there are predators, disease, lack of food and water and other factors that prevent the population from growing.
c) Organisms with better resources will be more successful in their reproduction efforts
This statement confirms that a mother who is able to carry out her pregnancy due to her access to resources like food and water will be able to keep her body in the best condition to accept another pregnancy.
d) Who gets better access to these limited resources?
The oldest way to access resources is food foraging, as I have just learned in another anthropology class. Many tribes follow the herd, the seasonal growth of certain fruits and the drought and rainy season. Their survival depends on food sharing and travel. When a tribe was denied access to the resources in the airport area in Africa and received cattle as a 'reward' or rather payment for staying out, the tribe almost became extinct. It seems apparent that species with access to limited resources are the ones that build upon them and expanded them to grow in contrast to the species that are depending on the carrying capacity of the land, while the ones that don't have access or the ability to provide for themselves through agriculture or horticulture are not doing well.
e) If the environment changes, the traits that are helpful or adaptive to that environment will be different.
An example for this would be the adaptation that took place in the Aymara tribe to the high altitude in the Andes. The people in this area of Bolivia have adapted biologically to the cold and harsh conditions of their environment. Through thousands of years of natural selection their bodies have become adapted to the low oxygen levels and they have a heart and lung capacity that is about 30% greater than other species that do not live in their environment.
f) In order for traits to evolve and they MUST be heritable.
Evolution takes time over a very long period of time. The biological conditions described in the previous bullet point show that the adaptation took place over generations, as they were physical changes. The traits would have been passed on by the parents, even if the baby would be born outside of the environment of the Andes, showing that it is not an environmental condition at the time of birth. The species living in the Andes had to pass a larger lung on from generation to generation for it to reach the right size to survive in the environment.
g) Individuals do not evolve. Populations do
As established in the foregoing bullet points, evolution effects a population and needs to be passed on by heritage. It is impossible for most species to procreate individually and the two that are needed are not able to create enough alterations to evolve. A population that adapts to the environment is able to gradually evolve and pass the traits on through genes from generation to generation.
h) Artificial selection
The first example for this kind of chosen reproduction that comes to my mind is the choice by many states in America to prohibit the breeding of any kind of bull terrier, such as a Pit Bull. This specific kind of dog is selected by humans, of that state, to not procreate.
4. Darwin had developed his theory of natural selection without the influence of Thomas Malthus for many years. The missing link for him was to find out how the new species came about. Malthus was not at all interested in the natural selection and evolution of species and based his focus on population only. Darwin was influenced by his mentor Charles Lyell, who showed him the geographical influence on natural selection and his grandfather, who wrote a poem about all species having the sea as their center. In addition he took the trip to South America as a young man and witnessed the difference in species of certain birds. He had made all the connections up to the point of natural selection and evolution. Thomas Malthus and his findings helped him considering the resources that impact population and answered a question that took him a step further in understanding. He had no doubt that there was a natural selection.
5. The church affected Darwin a great deal, as his theory went against the believe at the time that all species were created by a divine power and that there was a fixity of species, meaning that all stays as it was created. In the documentary Darwin was encouraged by his brother to talk about his findings. Fear for his life and the destruction of his career must have prevented him from publishing his book "The Origin of Species" until some 23 years later. His theories not only went against the first book of Genesis in the bible, but also again any known natural history. His publication came out at a time, where his life or career were no longer in danger. The church does not see him as an atheist, an association that was made with anybody who questioned divine creation, and Charles Darwin's remains are at Westminster Abbey in England, alongside another great scientist, Sir Isaac Newton.
