Topic 5.2 – Natural Selection xkcd.com
Natural selection can only occur if there is variation among members of the same species. Natural Selection is based on several prerequisite conditions: Genetics increases the diversity of life Species tend to produce more offspring than an environment can support Individuals within a species can pass down traits to their offspring http://entnemdept.ufl.edu/creatures/misc/gastro/brown_garden_snail03.jpg AP Bio Adaptations and characteristics that are acquired over a lifetime are not heritable. Lamarck believed this to be true, but was disproven. X These tiny differences make the difference between successful and unsuccessful species in the environment. http://c85c7a.medialib.glogster.com/media/a8/a866dd96f179b7d0f866c3debdc74c006d2c50d7a840d55573c23f5ed7cba1fe/competition-hirschkampf-743015-jpg.jpg
Darwin’s original voyage to the Galapagos is a popularly known story. What is not often talked about is the work of Rosemary and Peter Grant, who solidified what Darwin thought he saw using modern scientific techniques. Check out this video and see if you can answer the following questions: What is unique about the Galapagos islands that makes them ideal for this type of study? How do scientists know that the finches came from one common ancestor? What are the beak shapes and sizes evidence for?
Natural Selection leads to one of two distinct variations in a population of organisms: Characteristics that make the organism better adapted are increased in frequency. These organisms always survive and produce more offspring – and hopefully pass on the trait that gave them this advantage. Characteristics that make an organism less well adapted are decreased in frequency. These organisms can often not live to reproductive age or will not be selected out of the population to have offspring. How well are these principles displayed in this simulation? Does this happen each time? Or simply in general? http://www.biologyinmotion.com/evol/index.html
Bacteria provide an ideal example of real world evolution that happens during our lifetimes. Review: What structure unique to prokaryotes allows for evolution to occur at a much more rapid pace?
The evolution of antibiotic resistant bacteria comes at a scary time for humanity. MRSA Prevalence over last 70 years Number of new antibiotics on the market What makes this such a scary time in medicine? What data from these graphs can you use to support your conclusion? This author thinks this is a catastrophe. How credible is her argument? http://www.medicaldaily.com/antibiotic-resistance-will-kill-10-million-people-year-2050-report-shows-grim-future-316730