Blog #4 - Types of Selections

Describe the three types of selection: directional, stabilizing, and disruptive and gave an example of each in your own words.


When individuals at one end of the curve have higher fitness than individuals in the middle or at the other end, directional selection takes place. The range of the phenotypes shifts as some individuals fail to survive and reproduce while others succeed. An example of a directional selection is when a population of seed-eating birds experiences directional selection when a food storage causes the supply of small seeds to run low. When individuals near the center of the curve have higher fitness than individuals at either end of the curve, stabilizing selection takes place. This situation keeps the center of the curve at its current position, but it narrows the overall graph. An example of a stabilizing selection is when a human babies that is born at an average mass, it is more likely to survive than the ones that are born either smaller or the ones that are born much larger than average. When individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle, disruptive selection takes place. In such situations, selection acts most strongly against individuals of an intermediate type. An example of a disruptive selection is when an average-sized seeds become less common, and the ones that are larger or smaller seeds becomes more common.

Blog #3 - Microevolution

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


Microevolution refers to any evolutionary change below the level of species. It also refers to changes in the frequency within a population or a species of its alleles (alternative genes) Another thing it refers to is their effects on the form, or phenotype, of organism that make up that population or species. One way of variation that occurs is when all organisms produce far more offspring than one can survive to adulthood and reproduce. This means that many of those offspring will die without reproduction. Another way that variation occur is when the variation is heritable, that is if it exist in the parents and are passed on to the offspring. Organism vary in many ways. A third way that variation occurs is when some of those is heritable, which is when the variable traits affect an organism's fitness.

Blog #2 - Why is fossil record hard to interpret?

Why is fossil record hard to interpret?


Fossil record is hard to interpret because the animal is small. But also because the hard painstaking sand is covering the fossil. It is very hard to interpret a fossil without breaking it. When interpreting a fossil, the paleontologists have to find all the fossils of the animal. It is sometimes hard and sometimes easier, but doesn't mean it is easy. It is just a bit simple. It is very hard to interpret when it is a small animal because the bones of the fossils are very tiny. But when interpreting a large animal, it takes very long, but is somewhat easy, but it is still hard because they have to make sure not to break any of the fossil when interpreting it.

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

Why is evolution a theory and not a law?


Evolution is a theory and not a law because it is not yet been proven. A law is something that is already been proven with an explanation and is unlikely to be changed in the future. The research is mostly likely a hundred percent true. A theory is a something that is being explain from an observation and is possible to changed in the future. The research is not a hundred percent true. Evolution is a theory because it is an explanation of what is observed but not a hundred percent true. An evolution can not be tested because there is not enough information for it.