The Evolutionary Contributions of Thomas Malthus
I believe that the research and beliefs of Thomas Malthus directly influenced those of Charles Darwin and his theory of Evolution through Natural Selection. I believe this influence to have been positive in explaining the first step of how evolution works. In reference to a passage about Thomas Malthus found on a UCMP Berkeley Website ( http://www.ucmp.berkeley.edu/history/malthus.html ), he believed that plants and animals produce more offspring than what can survive. He believed the same about man and that poverty and famine were a divine intervention from god used to control the population. Although this belief differs from that of Darwin, the basic principals of it do relate, that all organisms have the potential of reproducing exponentially.
Darwin took that basic principal and refined it, saying that yes all organisms produce more offspring than what can survive, but the factors that lessen the populations are not divine, but natural. Darwin believed that natural causes, as well as genes, can shape a population over time so they adapt to their surroundings and he supported this by providing evidence through fossils.
I believe that Darwin could not have developed his theory of natural selection without Thomas Malthus. I feel like over population is the first key to studying the need for natural selection. Although Darwin took his idea and refined it, I feel that Malthus' ideas are what sparked that whole realization that the populations can be affected by other sources.
In conclusion, I believe that the attitude of the church is what really delayed the eventual publication of his book On the Origin of Species because he really did worry about his reputation. According to the video "Who was Charles Darwin?" he was a well known and respectable man from a well known family. He know his ideas would challenge the church and the beliefs of other naturalists. However, with the help of his brother he decided to collect his thoughts and publish them through his book.
Hey Amanda,
ReplyDeleteYour post is very well presented and thought out. You made excellent points as to why Thomas Malthus was the inspiration for Darwinian Thinking. But my favorite portion of your post was when you showed the similarities between Malthus on human population, and Darwin on the theory that all organisms can reproduce exponentially.
"Darwin took that basic principal and refined it, saying that yes all organisms produce more offspring than what can survive, but the factors that lessen the populations are not divine, but natural."
Very well said!
I agree with Isaac, very well said. The whole idea on plants and animals producing more offspring than that can survive can be seen everywhere such a spiders and all the way up to the African lions. I'm very surprised with your conclusion because I had no idea that Darwin was such a well know and respectable man during his time.
ReplyDeleteAmanda,
ReplyDeleteI agree with your post. I too think Darwin could not have developed his theory with out Thomas Malthus' influence. Also, the church had a huge influence on Darwin and his family and he worried how the publication of his book would affect his wife and family.
Amanda,
ReplyDeleteI love how you connected Malthus' ideas with Darwin's, but also showing their main differences. The difference being that Darwin took Malthus' idea that it wasn't divine intervention that lessened the population, but through natural causes. I believe that without Malthus, Darwin wouldn't be able to form and connect his ideas on natural selection. Like you said "over population is the first key to studying the need for natural selection.
Yes, an important point from Malthus was the issue of exponential growth, but you needed one more piece of information from his paper to actually show how Darwin used Malthus work and this was the issue of arithmetic growth of resources. That sets up natural competition for these limited resources and it was this idea of competition that let Darwin to ask some key questions, such as 'Who gets those limited resources?" "Is it random or is there a pattern of selection?" and finally "Organisms with better access to resources will be more successful in their reproductive efforts." which led to the connection between beneficial traits being passed on through reproduction with differential success... presto... natural selection.
ReplyDeleteDarwin didn't know about genes just yet... he hadn't read Mendel's work, but he did agree that organisms could be explained through natural processes. That isn't part of his theory, that is part of being a naturalist.
I always hesitate about giving too much credit to any one scientist (or theoretician) for their influence over another person's work. Are they really that indispensable? But for Malthus (and also Lyell), I actually do wonder it Darwin could have put all the piece together without that key. Even Darwin recognizes the importance of Malthus in his writing:
"...it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The results of this would be the formation of a new species. Here, then I had at last got a theory by which to work".
http://www.ucmp.berkeley.edu/history/malthus.html
Good final section, though recognize that Darwin wasn't just concerned for himself. He was far from being a selfish man and was very worried about how publication would impact his family.