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.

The Chromosomal Disorders

I want to share this web that i found interesting and helpful during my study of the chromosomal disorder.
http://www.biology.iupui.edu/biocourses/n100/2k2humancsomaldisorders.html

and these are some questions to help learn and understand this chromosomal disorders

1. What is caused by the Patau Syndrome (trinomy 13)?
2. When does Nondisjunction occur?
3. What is the 4 types of changes in chromosome structure?

Hermaphrodites

A hermaphrodite is an organism containing both male and female genitalia. They are able to produce both male and female gametes by themselves. Most hermaphrodites are invertabrates, however there are some vertabrate hermaphrodites. Hermaphrodites are characterized into two major groups: Sequential and simultaneous.

Sequential hermaphrodites undergo a sex change during their life. their are two types of sequential hermaphrodites:

Protandry-when an organism is born as a male and then changes to a female. ex. Clownfish
Protogyny-when an organism is born as a female and changes to a male. ex. wrasses(a group of reef fish)

Simultaneous hermaphrodites contain both male and female sexual organs. An example of a simultaneous hermaphrodite is an earthworm.


How might a species benefit from being able to reproduce by itself?
http://icb.oxfordjournals.org/content/46/4/473.full

What might be some drawbacks to being a hermaphrodites?
http://leisureguy.wordpress.com/2006/09/26/the-drawbacks-faced-by-hermaphroditic-species/

If Alex Furman suddenly changed sex how would he be classified?
http://en.wikipedia.org/wiki/Hermaphrodite

Types of Cancer Treatments

There are a couple different types of ways to treat cancer, however it depends on what kind of cancer you have and what needs to be done to help stop or slow that certain type of cancer. One type of treatment is Chemotherapy it destroys cancer cells, stops the cells from spreading, and slows the growth of cells that have already developed. You can only get Chemotherapy through an iv, a shot into your muscle, a pill, or a cream that you rub on to your skin. Depending on the level of cancer you have you may need treatment everyday, every week, or every month but in between these treatments you must have a period of rest where your body can build healthy new cells. Another type of treatment is Radiation, where they use high-energy radiation to shrink tumors and kill cancer cells. One way to have radiation treatment would be through x-rays. They use radiation to shrink tumors in the brain, spine, growing in a bone, or in the esophagus. There is one problem with radiation treatment, there is the chance of ruining normal healthy cells. Another way to treat some cancers is through cryosurgery which is the use of extreme cold produced by liquid nitrogen to destroy affected tissue. It is used mostly for external tumors, early skin cancer, precancerous growths, and cervical cancer. Last there is a treatment called biological therapy, that works with your immune system. It helps to fight cancer and also helps with the side effects from other cancer treatments such as Chemotherapy.

This blog is intended to extend your knowledge on the effects of DDT exposure on the human cell. The following link leads to a site that I found very helpful in my studies: http://www.chem.duke.edu/~jds/cruise_chem/pest/ddtup.html.
1. How does DDT get into the cells and why does this pose a threat?

2. What is the importance of Potassium and Sodium inside nerve cells?

3. Why is the leaking of Sodium and Potassium dangerous?

CELL COMMUNICATION

Cell communication is essential for all multicellular organisms. All of the billions of cells of a human must communicate in order to achieve everyday things like eating walking or talking. communication among cells is also key in unicellular organisms that need to communicate with other organisms to get food and mate.by studing cell communication we are helping to answer some of the most important questions in biology and medicine. it is allowing us to learn how cells communicate in areas like embryological development to hormone action to the development of cancer and other fatal diseases.

the signals recieved by cells can come from other cells or from some change in the organisms environment and can take various forms. cells can sense and respond to electromagnetic signals, such as light, and to mechanical senses, such as touch. however cells most used form of communication is through chemical signals. so it is essensial for ells to commuicate with each other in order to function properly

http://kentsimmons.uwinnipeg.ca/cm1504/cellcommunication.htm

1) what are some ways cells communicate and why is it important for them to communicate?

2) how could cell communication help in the study of fatal diseases like cancer?

3) what would be some effects of cells not being able to communicate with each other?

Alzheimer's Disease

Alzheimer's disease is a progressive, incurable and ultimately fatal form of dementia. The symptoms of Alzheimer's disease occur because of the loss of neurons. One of the key features of Alzheimer's is the presence of aggregated proteins, also called amyloid fibrils. These fibrils are made up of the A-beta protein, which can form the starting core for these clumps on the cell membrance which may lead to Alzheimer's.

http://www.livestrong.com/article/23368-alzheimers-cell-disease/

1.) One theory about how Alzheimer's develops is the ability of these amyloid fibrils to disrupt the internal workings of neurons. How do these fibrils destroy neurons, and why do the cells not rid themselves of these damaged proteins?
2.) Explain the process of Apoptosis and does this process help or eventually hurt neurons?

http://www.sciencedaily.com/releases/2010/06/100625124544.htm

1.) High levels of aneuploidy may result in developmental abnormalities and disease. Explain why this occurs, and what the outcome for the patient may be.

classification of living things - brian 2

All terrestrial life forms are divided into kingdoms and are farther broken down into phylum, classes, order, family, genus, and species. Before kingdoms though, there are domains. There are three domains: Archaea, Eubacteria, and Eukaryota. There are four kingdoms: Protista, fungi, plantae, and animalia. These are just the first couple steps in classifying living things. This system has been around for a while and has been altered and revised many times due to new discoveries and advancements. Within each kingdom, species are farther classified into groups based on similarities. For example, the full classification of a human is:
Domain- Eukarya
Kingdom- Animalia
Phylum-chordata
(subphylum- vertabrata)
class- mammalia
order- primates
family- hominidae
genus- homo
species- sapiens.

Classification of living things - Brian

All terrestrial life forms are divided into kingdoms and are farther broken down into phyla, classes, order, family, genus, and species. There are four kingdoms: Protista, fungi, Plantae, and animalia. This is just the first step to fully breaking down the classification of living things.

Classifications of Life

Today we will be explaining the seven classifications of life which help scientists put animals, plants, and other organisms into categories. Putting animals, plants, and organisms into categories is important because it helps scientists avoid confusion. This system was created by the Swedish botanist Carl Linnaeaus in 1757, which we today refer to as binomial nomenclature. The seven classifications of life in descending order are: Kingdom, phylum, class, order, family, genus, species. In 1990, three domains were created seperating single-celled organisms(archaea), unicellular microorganisms(bacteria), and complex celled organisms(eukarya), which includes protista, animalia, plantae, and fungi.

Questions for the Responder:
1.) What is the kingdom, phylum, class, and order of the reticulated python?
2.) Why is the classificaton of eukaryotes a controversial issue?
3.) Explain cladistics and why they are important to the subjects we are studying?

Taxonomy- The Science of Classifying Organisms

There are many different organisms, and scientists needed a way to classify them. Carlos Linnaeus, an 18th century scientist, came up with a system called binomial nomenclature, which means a "two name system." The two names were Genus and Species. Other scientists would later update the system to include more categories such as Kingdom, Phylum, Class, Order and
Family.
Taxonomy is the science of classifying organisms. The largest category is called the Kingdom, and this is broken down into a smaller group called a Phylum. Class is smaller than a Phylum, and so on. There are five major kingdoms used to classify living organisms:

1. Animalia: made up of animals, i.e. ants, frogs, horses, humans
   
2. Plantae: made up of plants which are organisms that can use photosynthesis to make their own food, i.e. trees, grass, cacti, algae
   
3. Fungi: feed on dead organisms, help the decaying or decomposing process of these organisms, i.e. mushrooms, mold
   
4. Protista: one-celled organisms that have a nucleus, i.e. Amoeba, Protists, Euglena
   
5. Monera: one-celled organisms that do not have a nucleus, i.e. Eubacteria, Archaebacteria

Before scientists can classify an organism, they have to make sure that it is living. The guidelines for living things are:

• They reproduce
• They use and make energy
• They respond to the environment
• They adapt to their environment
• They grow

The Kingdom Animalia is made up of organisms from ants to bears and even includes humans.

The Kindgom Plantae consists of plants that are multicellular and able to make energy from the sun.

The Kindom Fungi consists of multicelluar organisms that do not make their own food. Most are decomposers that break down dead organisms. The most common fungus is a mushroom.

The Kingdom Protista consists of unicellular or single celled organisms, with a nucleus. Some can make their own food, but others do not. These organisms are so small that we have to use a microscope to see them.

The Kingdom Monera consists of organisms that are unicellular and do not have a nucleus. These organsims are called bacteria.

1. There are some nonliving things that can act like a living organism. These are not classified in the kingdoms of living organisms. An example of one of these organisms is virus. Even though it can reproduce inside a cell, why isn't virus considered a living organism?
2. What are the two major groups of bacteria?
3. How are the Genus and species names written according to binomial nomenclature?

Carbon Dating

Carbon dating is a type of radioactive dating used to identify the age of human, animal, and plant remains. This method uses an isotope of carbon, carbon 14, which is formed when cosmic rays enter our atmosphere, strike nitrogen, and change it into another element. This isotope is radioactive and has a half-life of 5,730 years. This means that the quantity of carbon 14 in an organism will be cut in half every 5,730 years. All organic matter has both carbon 12(the most abundant form of carbon) and carbon 14, which is much less in abundance. Since C12 does not decay scientists compare the ratio of C12 in a sample to the amount of C14 left and they then can estimate how much C14 was there to begin with. Today, the ratio in the atmosphere is about one C14 atom for every one trillion C12 atoms. Here is an example, if a fossil is discovered and there is one C14 atom for every two trillion C12 atoms, you can assume that the fossil is 5,730 years old since the radioactive carbon has decayed one half-life. Basically, scientists date organic material based on the amount of C14 left in a sample compared to the amount of C12.

There are several flaws with this method of dating. One is that the method only works for organic material that is 60,000 years old or younger because by the time something reaches that age, the amount of C14 left becomes untraceable. Scientists can only account for around 10 half-lives of C14. Also, we are assuming that the ratio of C12 atoms to C14 was the same in the past as it is today. Since radioactive carbon is forming 28-37 percent faster than it decays, our environment has not yet reached equilibrium and the amount of C14 in our environment is constantly increasing. We have no way of undoubtedly knowing how much C14 was originally in a sample.


Questions:
1. What is the instrument used to detect C14 and briefly explain how it works.

2. Into what element does Carbon 14 decay?

3. What is another way to find the age of organic material?

Paleontology

Paleontology is the study of ancient life. It includes organisms' evolution and interactions with each other and their environments. Since it is a “historical science,” researchers explain causes instead of conducting experiments. This science has been around since the 18th century.
Paleontologists study mainly fossils to learn the history of the earth and evolution of mammals. They can sometimes work together with archeologists, who primarily study objects made by humans and human remains, since they study the evolution of humans as organisms.
Due to an increase in knowledge, paleontology has been broken down into several subdivisions, all studying the fossils of different organisms. There are also different kinds of fossils that paleontologists study, like trace fossils and body fossils.

Questions (:
What is stratigraphy and how does it relate to paleontology?

Name and briefly describe two subdivisions of paleontology.

What is mass extinction, when was the last mass extinction, and what became extinct after it?

Paleontology

Paleontology is the study of prehistoric life, including organisms' evolutions and interactions with each other and with their environments. Paleontologists have made observations dating back to the 5th century BC. They study ancient plants, rocks, fish, dinosaurs, mammals, insects, and much more. They search for fossils in rocks from all over the earth, discovering clues that will help them recreate what life was like in the ancient past. Paleontology is a "historical science", which means that instead of conducting experiments to observe effects it aims to explain causes. Paleontologists study fossils to derive what conditions were like during the lifetime of the fossil. Paleontologists can look at a fossil found somewhere and determine the age of the environment surrounding the fossil such as ice or rock. Through a paleontologists studies they can confer reasons as to extinctions, ice ages, and global warmings.

Questions :



1) What is the difference between paleontology, arthropology, and archeology?

2) How do paleontologists date their fossils in order to define the time period from which they came?

3) How can paleontologists use their findings to pridict the Earth's organic and inorganic past?

Evolution is, simply stated, the gradual change and development of a species due to the environmental challenges it experiences. In this way, species have developed over the millenia in order to become well-adapted in their habitat. The Darwinian concept of "survival of the fittest" is a large part of the evolutionary sequence. Species which are not well-adapted to their environment usually die out and are replaced by a species with a better chance of survival.

Creationism (or creation science as it is sometimes called) is a direct contradiction to evolution. Creationism explains the development of species as being the product of an intelligent mind, more commonly refered to as God. The theory is based upon a literal interpretation of the Bible, with all modern-day species being develped at the same time as man, and without the process of natural selection taking place

1. What are some important court cases involving evolution and natural selection?

2. How was the theory of evolution and the theory of creationism developed?

3. How has each theory been "proven?"