Monday, December 13, 2010

TED Talk Project on Evolution of Virulence of Diarrheal Pathogens


This video talks about the transmission and the evolution of virulence of diarrheal pathogens. The way these harmful pathogens spread is from an infected human to water supply, the movement of that water supply that goes into collectable water which transfers into the drinking of contaminated water, which infects another human being. The main idea of the video focuses on the question of, does the disease evolve to a more mild strain once it has been transmitted? However the video does also suggest that the more water that is transmitted the more harmful the strain gets. This can be seen in a encouraging way because if we figure out what the mild strain is then maybe we could prevent people from getting the more harmful strains and only letting the mild strains be infective. This of course leads to the co evolution of virulence and antibiotic resistance. In the co evolution the two, the more increased in virulence the more increase in antibiotic resistance. The goal is to turn this around by cleaning up the water supply so we could get an evolutionary decrease in antibiotic resistance.

WORDS - 187


Paul W. Ewald is an evolutionary biologist who specializes in the evolution of infectious diseases. He attended college at the University of California, Irvine where he received his B.Sc in Biological Sciences in 1975. Then in 1980 he attained his PhD from the University of Washington in Zoology with specializations in Ecology and Evolution. Now Paul W. Ewald is currently the director of the program in Evolutionary medicine at the University of Louisville. He was the first recipient of the George E. Burch Fellowship in Theoretic Medicine and Affiliated Sciences. He has written many articles for scientific journals on topics ranging from territorial behavior to new strategies fro designing new vaccines. One thing that stood out with Paul Ewald to me is that he disagrees with the popular theory that genes alone dictate certain disease susceptibility. Much of his work has been featured in Newsweek and the New York times.


Organisms – an individual animal, plant, or single celled life form
Disease - disorder of structure or function in a human, animal, or plant, esp. one that produces specific signs or symptoms
Evolution - the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.
Host - Biology an animal or plant on or in which a parasite or commensal organism lives.
Natural Selection - the process whereby organisms better adapted to their environment tend to survive and produce more offspring
Pathogen - a bacterium, virus, or other microorganism that can cause disease.
Cholera - n infectious and often fatal bacterial disease of the small intestine, typically contracted from infected water supplies and causing severe vomiting and diarrhea
Antibiotics - a medicine (such as penicillin or its derivatives) that inhibits the growth of or destroys microorganisms.
Malaria - an intermittent and remittent fever caused by a protozoan parasite that invades the red blood cells.


Theme 1: Evolution
Evolution is the ability for biological organisms to change over time. Natural selection also plays a huge role on how biological organisms change over time. Natural selection tends to favor organisms that are more likely to cause damage, to exploit the host of that organism. Transmission of diseases also is a big deal. The most important type of transmission is waterborne transmission because diseases that are transmitted by water are more harmful. However when countries can protect their water supply it makes the harmful disease to a more mild strain. An example of evolutionary change in populations of organisms that we have been able to observe or have evidence of is disease organisms that are transmitted by water in South America especially in Peru, Ecuador and Chile. The disease was first spotted in Peru then moved north to Chile and South to Ecuador. Chile’s water supply is much more protected then Ecuador’s water supply. The statics show that the disease transformed to a more mild strain in cases in Chile than cases that happened in Ecuador. This information shows that the disease did evolve and change over time, depending on the protection of water sources. The evolution of organisms and diseases and how we can domesticate these diseases to a more mild strain can be instrumental to saving lives and helping third world countries conquer serve diseases.

Theme 2: Science, Technology & Society
Scientific research often leads to new types of technology that can leave positive impacts on our society as a whole. An example of technology and research comes from Alabama. In northern Alabama, the community was experience a high rate of malaria. Do to the cause of a large body of water that had been blocked up by a dam. Research was done and it turned out to be that when people get sick they are in hospital beds, or their own houses where mosquitoes cant get to them. Money was raised in the state to mosquito proof each house in the districts that were suffering from malaria. This was very helpful and stopped many people from getting malaria. The information is useful to us because it tells us that if you have moderate biting densities in an area (Sub Africa) you can eradicate malaria by mosquito proofing houses. Mosquito proof houses are the best solution because the only other solution at the moment is anti malarial drugs. Anti malaria drugs are good but not great because they are a short-term solution because there will be a resistance to those drugs because of how disease and organisms evolve through evolution. The scientific research data of malaria and finding the leading causes of it are crucial to making malaria cases milder. The mosquito proofing housing technology is beneficial to societies that have a higher concentrated number of mosquitoes in there areas. The scientific research to look at data and the technology innovations to help stop malaria, are truly beneficial to human society.


  1. This comment has been removed by the author.

  2. Johne, you need to put the vocabulary at the bottom of your video. Copy and paste. This should not be in a comment. See me if you have questions. Good start. Make sure you give attributions for all work that you take off the internet.

  3. need to read my first comment and you are late with your second checkpoint.

  4. Thanks for cleaning up your post. OK now you need to think about the two themes that your author is addressing. We have used these themes before when we discussed the end of a unit.

  5. Great articulation on the themes. Those were the exact themes that I would have chosen and you were able to provide examples to defend your chosen theme. Well done