Blog # 4 Describe the three types of selection: directional, stabilizing and disruptive and give an example of each in your own words

                     Directional Selection occurs when selection favors one extreme trait value over the other extreme. It ususally happens in the mean value of the trait under selection. A Disruptive Selection occurs when selection favors the extreme trait values over the intermediate trait values. In this situation the variance increases while the population is seperated into two different groups. It plays an important role in speciation. Stabilizing Selection happens when selection favors the intermediate trait value over the extreme values. Populations under this type of selection can usually go through a decrease in the amount of additive genetic variation for the trait under selection.

Blog #3 Explain what microevolution is? What are the three ways that variation occurs?

                   Microevolution is the change in allele frequencies brought about by mutation, genetic drift, gene flow, and natural selection. One of the ways that variation occurs is when mutations alter the order of bases in the nucleotides of DNA. Mutations can most definitely be rare and most mutations are probably harmful, but in a few instances the new alleles can be chosen by natural selection. Independent assortment and the Crossing over that happens during meiosis are two other ways that variation occurs.

Blog # 2 Why is fossil record hard to interpret?

         Fossil records are hard to interpret because fossils are often poorly preserved and hard to interpret. For example, identification is hampered by a lack of fossilized gonopods, which may be because the fossil forms had a primitive form of sperm transfer, or the fossils are immature animals. A similar problem is encountered when trying to establish whether differences in numbers of legs and segments are true differences.

Blog #1 Why is evolution a theory and not a law?

                       In science, a theory is an explanation. Where a law is a pattern that natural phenomena follow. So they're two different things. A law is great for predicting events, because we expect the events to follow the pattern. But the law won't explain why events follow the pattern. For that we need a theory. Both theories and laws can turn out to be wrong, and must be tested by considering what evidence we should find if the theory or law were false, and then looking for such evidence.