Authority — what are the author’s experience, credentials, or affiliations? What are their affiliations? look for sources with named authors who have the experience and knowledge
Credibility — where is the author getting their information? Do they list their sources?
Audience/Purpose — is the author speaking to a particular audience? Do they have a particular perspective, or agenda? Are they trying to sell you something?
Currency — does the website have a date? Is it maintained and updated?
Most characteristics in humans are not Mendelian but a few of them are. Using reliable websites, find information about Mendelian characteristics in humans (or other animals). You might also look for information about traits that we used to think were Mendelian but now know are polygenic. Include the URL for any sites you use.
Epigenetics is an exciting emerging field in genetics that has the promise of helping us finally put to rest the so-called “nature v. nurture” debate. The Carey article mentions several examples of epigenetics in humans. Using reliable websites, find information about other examples of epigenetics in humans or other animals. Include the URL for any sites you use.
Darwin did not know about Mendel’s work with pea plants while he was developing the theory of evolution by natural selection, which means that, although he elegantly described natural selection and provided a great deal of evidence for it, he did not know how traits were passed from parents to offspring. In the 20th century, as more was learned about DNA and genetics, Darwin’s work and Mendel’s work were finally put together and the mechanism for how traits were passed from parents to offspring became understood. This is what we call the Modern Synthesis, which was a significant expansion in evolutionary theory, building on Darwin’s ideas. The modern synthesis largely focused on how variation is produced and distributed in populations. What are the 4 main mechanisms for the production and distribution of variation in populations? Using course materials and the Internet, find some specific examples of each kind.
Evolutionary theory predicts that deleterious genetic diseases, like Tay-Sachs, will be selected out of populations and, therefore, occur at a very low rate. However, Tay-Sachs is a disease that occurs at a surprisingly high rate among Ashkenazi Jews. Diamond’s article, “Curse and Blessing of the Ghetto”, demonstrates how evolutionary theory can help explain why some genetic diseases are more common in some populations than others. Diamond presents 4 possible hypotheses to explain why Tay-Sachs is more common among Ashkenazi Jews than other populations. What are the 4 hypotheses he proposes? Which is the hypothesis he argues is the most plausible explanation?
In discussing this question, you can also integrate information about the genetics of TS and protein synthesis to help demonstrate how all of the material we have been talking about so far comes together.
Tay-Sachs is an example of a genetically inherited disease that is more common in one population than in others and can be understood from an evolutionary perspective. What are examples of other genetically inherited diseases that can be understood from an evolutionary perspective? Use the Internet to find examples.
Remember to choose only high quality, reliable websites. Avoid sites like Wikipedia, About.com, listverse, and other sites that can be edited by the public or are simply copying information from original sources. Make some effort to find more reputable sources for academic work. Include any URLs you use.
The Moore article you read for class this week presents 4 hypotheses for the origins of AIDS. Discuss one or more of the hypotheses Moore presents, including the evidence for the hypothesis and any challenges to the hypothesis he suggests. Which hypothesis does Moore think is the best explanation for how HIV originated in humans?
Understanding evolution is essential for the practice of medicine. Based on the pages from Understanding Evolution assigned this week, address these three questions:
· Why is evolution relevant in the medical field?
· Why does evolution matter when it comes to fighting pathogens?
· What role does evolution play in hereditary disease?
Feel free to use the information presented on the Understanding Evolution pages to answer these questions or use the internet to search for more examples. If you do an internet search, please be sure to use only reputable websites that are appropriate for college-level work (not Wikipedia or about.com) and to include the URL.
Topic 8 focuses on the principles of classification and macroevolution. One of the most powerful predictions that evolutionary theory gives us is that all life on earth is related, that it all descended from the same initial simple single-celled organisms that evolved more than 3.5bya. So, any two organisms share a common ancestor. One of my favorite websites is Time Tree (Links to an external site.)Links to an external site.. Using the amazing database on this site, you can enter any two organisms and it will give you an estimate of when they shared their last common ancestor. The website presents a lot of additional information that is extremely interesting and useful but is not relevant for this class. You can just focus on the dates of species divergence.
Take a look at the site and share what you find out about how organisms are related.