directional,stablizing, and distuptive

     Directional selection favors those individuals who have extreme variations in traits within a population. Stabilizing selection favors the norm, the common, average traits in a population .Disruptive selection, like directional selection, favors the extremes traits in a population. Disruptive selection differs in that sudden changes in the environment creates a sudden forces favoring that extreme. Directional occurs when selection favors one extreme trait value over the other extreme. This typically results in a change in the mean value of the trait under selection. Distuptive occurs when selection favors the extreme trait values over the intermediate trait values. In this case the variance increases as the population is divided into two distinct groups. Disruptive selection plays an important role in speciation. Stablizing occurs when selection favors the intermediate trait value over the extreme values. Populations under this type of selection typically experience a decrease in the amount of additive genetic variation for the trait under selection.

The fossil Record

   The fossil record is incomplete because very few organisms were preserved as fossils. organisms tend to decay before becoming a fossil. Animals with hard parts are preserved more easily and geological processes may destroy fossils. Darwin believed that the fossil record showed the history of life on earth.The fossil record of all species is not complete because the circumstances for fossils to occur is very rare.

Microevolution

          Microevolution is a change in gene frequency within a population. This change is due to four different processes mutation selection , gene flow and genetic drift
population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance
Microevolution can be contrasted with  marcoevolution, which is the occurrence of large-scale changes in gene frequencies in a population over a geological time period  difference is largely one of approach. Microevolution is reductionist, but macroevolution is . Each approach offers different insights into the evolution process. Macroevolution can be seen as the sum of long periods of microevolution, and thus the two are qualitatively identical while being quantitatively different.

why is evolution a theory and not a law

  Different theories and laws can end up 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. For example if the theory of evolution were false then we shouldn't expect the similarities between living things to show a nested hierarchy, where in two species share many similarities some of which are shared by more distantly related species, and some of those of which are shared by more distantly related species; etc. Since we do in fact find such nested hierarchies of similarities, and since we would not expect to find such hierarchies if everything were made from scratch to look as it does now, that is strong support to indicate the theory is correct

last blog

my favorite topic activity this year was reading the hot zone book. It was cool reading it but I liked the movie better.  my least favorite subject this year was nothing, I was ok with all of them. If I could change anything it would be not having to do anything on the computer. I would change it because I always forgot to go the computer and do the activity.

DNA crime investergators best friend??

 DNA has changed the way police solve crimes. Now with DNA the cops can get the badguy with just a fingerprint, blood sample, hair sample or anything else the cops find that aint the victums. With the technology now a days the cops will be knocking on the bad guys door before the guy or girl can get out of town. The two main tests the csi guys run on DNA are PCR and RFLP. These two tests help the cops catch the badguy.

gattaca movie

In the movie gattaca the parents are able to pick there kids traits. I think this is pretty cool but not fair. Its not fair because parents coul create a kid to be stupid or stupid. they could be able to lift 100 pounds or just 10.  And what about the rest of the normal people. I think that if kids were picked traits and not natural it would not be normal.