Current Human Evolution/Natural Selection

Natural selection is the process by which traits become more or less common in a population due to consistent effects upon the survival or reproduction of their bearers. The traits differ due to where the population is from and what their environment was at the start of their ancestors. An example of this that i read about was Charles Darwin's discovery that happened over 150 years ago. His discovery is responsible for transforming dinosaurs into birds. Darwin's natural selection is the process by which nature rewards those individuals better adapted to their environments with survival and reproductive success. His validity of his natural selection have been attacked recently by a small group who argue that it cannot explain all the complexity seen in nature.
The human brain is said to still be evolving. Several experts criticized the finding of the brain still evolving. They said that it was far from clear that new alleles(genes) conferred any cognitive advantage or had spread. Also different populations have different allele evolutions. You can compare this to malaria defenses. The genetic defenses against malaria differ in Mediterranean and African populations. Another example is when two people did study on Microcephalin haplogroup D and ASPM haplogroup D. They found that with the Microcephalin haplogroup D it is virtually universal in the new world but with ASPM haplogroup D variant is most common in Europe and West Africa and less so in East Asia. I think this is because the human brain and other traits differ due to the location of the people and what their environment, climate, or life is like.












http://whyevolutionistrue.wordpress.com/2009/04/06/recent-selection-in-human-populations/

http://www.livescience.com/health/051102_natural_selection.html

http://www.pbs.org/wgbh/nova/evolution/are-we-still-evolving.html

1. How can you survey the human genome for recent signs of natural selection?

2. What major part of our body is stilll evolving?

3. What did the evolutionary geneticist Bruce Lahn report about the evolving brain?

Disruptive selection explains changes in population genetics where traits extreme values are superior to its intermediate values. In this instance, the variance of the trait increases dividing the population into two groups. Another name for this is diversifying selection. An example I read was made about a population of rabbits. There were rabbits with black fur, white fur, or gray fur. If the rabbit had black fur that meant the genotype was BB. If it had white fur the genotype bb and with gray fur the genotype is Bb. If these rabbits were in an area with very dark colored rocks and very white colored stone then the rabbits with black or white fur would easily be able to hide from predators by the same colored rock as their fur. The rabbits with gray fur would stand out against the black and white rocks and be at a higher risk for predators seeing them. Due to the environment the gray rabbit is living it would be disruptively selected because of its fur color.

Questions:
1. What is another example of this type of natural selection?
2. What is a genotype and what does it have to do with the fur color of the rabbit?
3. How does this type of selection differ from the other types?

origins debate

http://ejournal.belhaven.edu/religion_philosophy/deconstructing_origins_debate.htm

1. What did Stephan Gould argue about concerning religion and evolution?
2. What is the supposed probability that evolution could occur?(keyword: random shuffling)
3. For what reason is it that evolutionists believe that intelligent design should not be considered science?(after into)

http://www.eurekalert.org/pub_releases/2010-06/uouh-agp060910.php
1. What are CNV's and how are they related to autism?

2. The study found three new genes, SHANK2, SYNGAP1, DLGAP2, what do these genes belong to? And what does identifying these genes do?

http://www.autism-society.org/site/PageServer?pagename=research_envirohealth
3. The research found that children that have autism or are at risk for having autism have what?

Color Blindness

•  The number in this picture is 74. A red and green color blind person would have no idea there was even a number there. To them it would just look like a circle.

1. Color blindness- Ten million men in the world are color blind (red and green are seen as identical).      Interestingly enough only 600,000 women have the same disorder. That's because the mutation is only      located on the X chromosome. Men only have one X chromosome so they have a much bigger chance of getting the disease. Women have two X chromosomes so their chances of getting it are much higher because the mutation must occur on both chromosomes.  

• Being red and green color blind is the most common type of color blindness around.
• It can also be called deuteranopia-green blindness, deuteranomaly-green weakness, protanopia-red blindness, protanomlay-red weakness, and Daltonism.
• It is called Daltonism because John Dalton and his brother were both severally colorblind.
• He also wrote the first scientific paper on red and green color blindness.  

   2. Problems of color blindness-people may not be able to differentiate between red and green traffic signals. Also, if you were and your friends were out in the sun, you may not be able to know how red you/your friends are getting.

3. Severity of color blindness-Color blindness can range from being very severe of just moderate. Even in the moderate stages the entire color spectrum is affected, not just red and green. Depending on the severity is where you may experience deuteranopia or protanopia which is complete blindness of both red and green.

The colors on this sheet would be examples of colors confused by a color blind person depending on the severity of it.

Hemophilia

What Is Hemophilia?


Hemophilia is the body's inability to control blood clotting, which is used when a blood vessel is broken. Hemophilia A is the most common form of this disorder. Hemophilia B is the second most common form of this Genetic disorder. Hemophilia lowers blood plasma levels of the coagulation factors needed for a normal clotting process. When a blood vessel gets injured a scab will form but the missing of coagulation factors prevent fibrin formation, which is completly necessary for it to maintain a blood clot. If you have this disorder you do not bleed more then people without it, you just bleed longer then people without it. If you have a severe case of this disorder you only need a minor injury for you to bleed for days or even weeks, in some cases you dont heal all the way. In the areas such as the brain or joints, this disorder could be fatal.


Symptoms?

Symptoms of hemophilia are usually first noticed during infancy or childhood. But some people who have milder forms of hemophilia may not have symptoms until later in life. Although there are different types of hemophilia, the symptoms are the same.

The following are signs of hemophilia that may be noticed shortly after birth:

• Bleeding into the muscle, resulting in a deep bruise after receiving a routine vitamin K shot
  
• Prolonged bleeding after a male child is circumcised
  
• In rare cases, prolonged bleeding after the umbilical cord is cut at birth

Other symptoms of hemophilia include:

• Bleeding into a joint or muscle that causes pain and swelling.
  
• Abnormal bleeding after an injury or surgery.
  
• Easy bruising.
  
• Frequent nosebleeds.
  
• Blood in the urine (hematuria).
  

Queston: http://www.nhlbi.nih.gov/health/dci/Diseases/hemophilia/hemophilia_treatments.html

1. Hemophilia is treated with replacement therapy, what is replacement therapy?

2. Name two complications of replacement therapy.

3. What chromosome is the carrier of hemophilia? And is it possible for a woman to be a hemophiliac? Explain.

Genetic Diseases

Also called genetic disorders, they are caused by abnormalities in a person's DNA. These abnormalities can range from a small mutation in a single gene, to the addition or subtraction of entire chromosomes.

Types of Disorders:

• Multifactorial Disorders, also called complex or polygenic disorders, are the result of mutations in multiple genes. They are associated with environmental causes.
• Hypothyroidism
• Colon Cancer
• Ovarian/Breast Cancer
• Alzheimer's Disease
• Chromosomal Genetic Diseases have the absence, duplication, or alteration of entire chromosomes. Abnormalities in the structure or number can result in some of the most dangerous genetic diseases. 
• Cri-du-Chat syndrome
• Down syndrome
• Klinefelter syndrome
• William's syndrome
• Turner syndrome
• Single-Gene disorders result when there is an alteration of one gene. Genes code for proteins, which perform most life functions. When a gene is mutated so that its protein product can no longer carry out its normal function, a disorder can result.
• Cysitc fibrosis
• Huntington's disease 
• Neurofibromatosis 1 (NF1)
• Sickle cell disease
• Mitochondrial Disorders are rare types of genetic disorders caused by mutations in the nonchromosomal DNA of mitochondria. Mutations in the mitochondrial DNA can cause many undesireable results.
• Leber's hereditary optic atrophy
• Kearns-Sayre disease
• Myoclonus epilepsy
• MELAS

Questions:

1. Aside from the four examples I have provided of multifactorial disorders, find one more and describe the environmental causes it is coupled with.
2. Both males and females can get mitochondrial diseases equally, but always get it from their mother. Explain how this is possible.
3. Describe some ways people at risk of or have a single gene disorder can be helped, despite the fact that there are no known cures for these disorders.