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Biology - If farmers continue to use large quantities of chemicals

1. If farmers continue to use large quantities of chemicals to control insect pests and weeds what problem (from an evolutionary perspective) are they likely to encounter?
2. In terms of gene pools, what is a major potential consequence of isolating wildlife in reserves.
3.Tay-Sachs disease, which is inherited as a Mendelian recessive, occurs in Ashkenazic Jews in one of every 3,600 births, Estimate the percentage of this population that carries the allele,
4. What is genetic drift? A herd of deer in a national park grows rapidly for several years and then experiences an epidemic disease that kills 90% of the herd. What is a probable consequence of this event?

Solution Preview

1. What the farmers are doing is preventing the process of natural selection, which would normally weed
out the "weak" within the populations of potatoes, tomatoes, or whatever it is that they are growing. Because of this, the plants are likely to have a very low resistance to pest or diseases, so if they are faced with an infection or
pest that they have not been sprayed for (or something that is resistant to the chemicals) they are probably going to be wiped out.
2. By isolating wildlife in reserves, you are splitting species into small groups. This can create a less varied gene pool within each smaller population, and can also lead to genetic drift. Over time, the small populations, if they are completely cut off from each other, may diverge genetically and form separate species that can no longer interbreed. Also, by ...