Alex+Ch.

=Wikipost #3 - Dynamic Equilibrium//: LSD & Hallucinogenic Drugs,// Jan. 24=

//Magic mushrooms, DMT, LSD, mescaline and salvia are some of the most common hallucinogens that exist.//
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While these drugs come from all different sources, they are all set on targeting one are of the body: the senses. Since that covers a wide variety of possible effects, it's easy to understand that the effects of hallucinogens depend on many different factors are considered very unpredictable. The effects you might feel from taking a hallucinogen depend on a large list of things: what you take, how much you take of it, your general health, your current mood, where you use it and who you are with when you use the drug. Hallucinogens are known for being capable of changing perception, thought, emotion, and consciousness. One thing that separates hallucinogens from other drugs is that some can introduce new experiences completely different from those experienced when conscious. For example, most stimulants and opioids will only amplify feelings that already exist, but LSD may cause you to actually "experience" situations that aren't real or physically feel something that is not "actually" happening.======

===__Brief History:__===

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Natural hallucinogens have proven to be included in many cultures dating as far back as 3000 years ago when The Rigveda ( Hindu holy book) mentions "soma": a sacred substance from a hallucinogenic mushroom, which was believed to have induced higher levels of consciousness. The Aztecs have also described the ceremonial use of teotlaqualli, a paste made from ololuiqui, another hallucinogenic flower, with the intent to eliminate fear and to place the use in a proper mental state. Hallucinogens have also been proposed as the cause of "immoral and illicit" behavior of the alleged witches of the Salem witch trials.======

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In 1938, the first (and what would become the most commonly used) synthetic hallucinogen was accidentally created by Sandoz laboratories by a man named Alfred Hoffman. It wasn't until 4 years later, however, that LSD's psychoactive properties were discovered when Hoffmann was inadvertently exposed to his own drug & started to hallucinate. The United States CIA started to perform tests on unaware participants to test the drug's ability to serve as an interrogation tool or as a mind-control agent.======

__LSD__
It wasn't until the late 1950s and early 1960s that LSD ( Lysergic Acid Diethylamide) became popularized by the media and experimentation with psychedelics reached a new peak. When the user takes LSD, it acts as serotonin (a neurotransmitter involved with regulating moods, appetite, sexuality, and sleep and sensory perception). Because LSD has such unpredictable effects, not much is known about how it affects the brain. Scientists have concluded, as with most other drugs, that LSD interferes with how the body's serotonin neurotransmitters work; however, It may work as an inhibitory, a stimulant, or both. Drugs researchers have determined that the two main brain areas that are affected by LSD are the cerebral cortex (involved in mood, cognition, perception) and the locus ceruleus which is described as the brain's "novelty detector" for important external stimuli.



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Hallucinogens as a whole all have similar effects on the brain (or at least have the potential to). Using the various types of psychedelic drugs can all lead to the interconnection between audio, visual, and tactile perceptions, which means sounds could be seen or felt while different colours may appear sharper and even emit a strange noise to the user. Having clear visions with your eyes closed is also common with LSD users (hence the hallucinogen part). Time flow, self-perception, and your perception of the world around you are also all strangely and unpredictably altered. Taking a hit of acid will stimulate centers in the sympathetic nervous system causing pupil dilation, increased body temperature, increased blood sugar levels...etc.======

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While some trips cause the user to feel sensations that are enjoyable and mentally stimulating, LSD's unpredictability results in bad trips that are most definitely not pleasing. Bad trips can include strong agitation, anxiety, paranoia, nightmarish feelings and loss of control. Another danger to using LSD is that any subjects with prior psychiatric troubles may experience psychosis or other mental disorders after a hit and there have been quite a few stories regarding LSD users dying as a result of being so high that they believed they could fly and have jumped of buildings with the intentions of succeeding. Another common effect of using LSD is flashbacks that occur a few days after consumption. They can be totally random or due to the stimulus associated with the memories of LSD intake and the user may actually relive the sensation of high caused by the substance. This of course can be incredibly dangerous if you plan on doing activities such as driving.======

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__//Further Reading://__
[] - In depth documentary discussing the history and popularization of LSD. [] - Web page that thoroughly explains what scientists know about how most hallucinogenic drugs work. [|http://www.npr.org/blogs/health] - Interesting article of a study done which adds to evidence that psychedelic drugs have no link to mental problems [|http://fullcomment.nationalpost.com/2012/11/13/oliver-sacks-] Story about a doctor who's experimentation with hallucinogenic drugs has helped shaped his character.

__//References://__
http://flipper.diff.org/app/items/info/4051 http://serendip.brynmawr.edu/exchange/node/1880 http://science.howstuffworks.com/lsd.htm http://www.elmhurst.edu/~chm/vchembook/672hallucin.html http://www0.health.nsw.gov.au/factsheets/drugAndAlcohol/hallucinogens.html

= = = = = = = = = = =Wikipost #2 - //Evolution:// Bottlenecks & The Founder Effect Dec. 1=

What do American bison, Northern elephant seals, and Galápagos giant tortoises all have in common? (apart from all being super adorable) ==

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- These animals are all examples of bottleneck populations! __//Bottleneck populations//__ If we were to examine the population history of all the animals above, we'd see that each one has gone through quite hard times as a species. Let's look for example at the Northern elephant seal. Throughout the 18th century, elephant seals were hunted extensively to the point of near extinction (researchers estimate the global population dropped to around 30 in the 1890s); however, the elephants seals prevailed and now exist in the hundred of thousands primarily along the Pacific coast of North America. But what does this mean for the new, recovered population of Northern elephant seals? Well, we know that the entire current global population of these elephant seals must all descendants from those 30 or less individuals that existed over 120 years ago. This means that there is very little genetic variation within the population compared to the Southern elephant seals around Antarctica. We call this type of population a "bottleneck population". Bottleneck populations can be the result of any sharp reduction in size of a population due to environmental factors such as an earthquake or a drought, as well as human activities like with the Northern elephant seal. The population then recovers from being on the brink of extinction, but with a drastic reduction of genetic variation within the population. As a result, bottleneck population are very susceptible to diseases and genetic mutations.



//__The Founder Effect__// Similar to bottlenecking, the founder effect is when a small group members from a larger population establish a new population in a new location. Like a bottleneck population, the new population may be genotypically and phenotypically distinct from the parent population. With the newly established population, the allele frequency is likely to change drastically over time. This means that the amount of certain variations of genes (alleles) present in a population will change in one of two ways: either the allele frequency will diminish and that allele will be lost over time due to procreation between individuals that __don't__ possess that particular allele, or the allele will appear more frequently as those who __do__ possess that allele procreate. Clearly, those new populations can easily display differences in phenotypes and genotypes from the parent generation and other new populations created by the founder effect.

Two of the most well-known examples of the founder effect are the 16,000- 18,000 Old Order Amish people in Lancaster County, Pennsylvania, and the people of the Lake Maracaibo region in Venezuela. The Amish in Lancaster County are descendants of only a few dozen individuals who migrated from Germany during the early 1700s. In the last 40 years of the 20th century, there were 61 babies born throughout 23 families with microcephaly: an extremely rare fatal genetic disorder.

As with those in Lake Maracaibo, around 150 people during the 1990s had Huntington's disease and can all trace their ancestry to a woman named Maria Concepción Soto who moved there in the 19th century and had an usually large amount of descendants

Here is a video that demonstrates through example what bottlenecking and the founder effect can to do a population media type="custom" key="24545954" width="496" height="310" align="center"

__//Bottlenecking & the Founder effect in// humans__

Just like the American bison, Northern elephant seals and Galápagos tortoises, the human race has been just as experienced with bottleneck populations as many other species. Humans were not, however, commonly on the brink of extinction, so the founder effect is normally viewed as the most likely situation involving human populations. The Toba catastrophe theory is the theory that revolves around the supervolcanic eruption of Lake Toba, Sumatra, Indonesia around 69,000 - 77,000 years ago. It's said that this event caused a global volcanic winter for 6-10 years and is a cause of a bottleneck in human evolution due to the effects of the eruption on the global climate. The human population decreased to about 3,000 - 10,000 individuals and according to the theory, the genetic differences between modern humans may directly reflect the changes within the last 70,000 years or so, instead of it being gradual over millions of years. This theory, however, has been doubted by many evolutionists for obvious reasons.



[] - more info on the volcanic winter caused by the eruption of Lake Toba from the "Journal of Human Evolution" by Professor Stanley H. Ambrose, Department of Anthropology, University Of Illinois, Urbana, USA. [] - an article discussing the how cheetahs are recovering from their population bottleneck they experienced 10,000 years ago by "cheating" where the females have multiple male partners and create litters in which cubs have high genetic variability. [] - paper from the US National Library of Medicine about the founder effect among French Canadians. [] - an interesting article that talks about the "Big Bang of Human Evolution" and how a small population bottleneck out of Africa 2 million years ago jumpstarted the process of human evolution.
 * //__Further Reading:__//**

References: http://en.wikipedia.org/wiki/Population_bottleneck http://news.discovery.com/human/genetics/human-diversity-bottlenecks.htm http://evolution.berkeley.edu/evosite/evo101/IIID3Bottlenecks.shtml http://en.wikipedia.org/wiki/Northern_elephant_seal http://www.nature.com/scitable/definition/population-bottleneck-300

= = = = =**Wikipost #1** - //Genetics//: Mitochondrial DNA Oct. 11=

__//Mitochondrial DNA//__
Those cute little energy-producing “powerhouses” that are essential to life in eukaryotic cells are way more than just another organelle! Despite being known as the lead role in cellular respiration, mitochondria have another remarkable trick up their sleeves. The mitochondria located within the cells of each and every one of us contain it’s very own independent genome. As the majority of people automatically associate DNA with the nucleus, mitochondrial DNA is often left out of the picture; however, despite its lack of attention, mitochondrial DNA is still a large part of the building instructions to most multicellular organisms.

// **__Structure & Function__** //
In humans, mitochondrial DNA is significantly smaller than nuclear DNA with only around 16,600 base pairs and 37 genes. Thirteen genes are responsible for making enzymes involved with oxidative phosphorylation (the process in which sugars and oxygen create adenosine triphosphate, the cell's main energy source) while the other genes are responsible for making either tRNA or rRNA, the chemical cousins of DNA.  In most multicellular organisms, the mitochondrial DNA is circular, double stranded and covalently bonded. As for human mtDNA, there are usually somewhere between 100-10,000 copies of DNA per cell (quite a bit more than in nuclear DNA)! Each strand is either a "heavy" strand or a "light" strand. The heavy strand is rich in guanine and is responsible for encoding 28 genes while the light strand is rich in cytosine and encodes 9 genes for a total of 37.



__//**Inheritance** //__
If there's one thing that must be known about mitochondrial DNA inheritance, it's that it's maternally inherited, meaning it's only passed down from mother to child. Even though both sperm and egg cells carry mtDNA molecules, most multicellular organisms will only receive that of the mother. Why is that? Well, the amount of mtDNA in an egg cell outnumbers the amount in a sperm cell...by a lot. About 100,000 to 1,000,000 mtDNA molecules are found in an average egg while there may be up to 1,000 in a sperm cell. Also, the mtDNA is located within the sperm's tail and the tail is sometimes lost during the fertilization process. The only creatures in which mtDNA is regularly transmitted from both parents are bivalves.

Moms are pretty neat, and since mitochondrial DNA is maternally inherited, it's possible for researchers to trace maternal lineage far, far back in time! This is possible because unlike the majority of DNA found in the human cell which is mixed as its passed down form generation to generation, mitochondrial DNA remains unmixed as a result of the strict line of descent from mother to child. This means that we share our mtDNA with all others who descended from the same maternal lineage. So by testing our own mtDNA, we are indirectly reading the mtDNA of our mother, her mother, and her mother and so on and so forth thousands and thousands of years in the past.

Here is a short video that explains the formation of the mitochondria, it's DNA and an introduction to the concept of Mitochondrial Eve. media type="custom" key="24078260" width="445" height="325" align="center"

**//__Mitochondrial DNA testing __//**
To test our mtDNA, researchers use a sequencing process to look for changes in the mtDNA of individuals, then compare them to other individuals. This enables researches to use the similarities to determine which individuals share the same maternal lineage and which do not. The blue coloured section called the "d-loop control region" at the top of the circular genome on the image above is where the testing takes place. This section is made up of three main regions: HVR-1, HVR-2 and the coding region. To test our mtDNA, we need to test one of these regions to look for single nucleotide polymorphisms (changes in mtDNA that are passed down to further generations). The HVR-1 test is the base test and the most common. This region contains an abundance of SNP (single nucleotide polymorphism) markers so is the most useful in determining maternal lineages. The HVR-2 region has additional markers that will add to the search and give more details while the coding region will provide an even clearer conclusion once a match is found.

**//__Mitochondrial Eve __//**
The man in the video introduced to us the idea of Mitochondrial Eve. But who was she? Mitochondrial Eve refers to the matrilineal most recent common ancestor (MRCA) of all human beings alive on Earth at this very moment meaning she is the most recent woman from whom all living humans descend. By definition, all the mitochondrial DNA within every living human being is directly descended from her, differing only because of mutations that have occurred over generations. It's estimated that she lived around 140,000 - 200,000 years ago, most likely in East Africa. Unlike common belief, the MRCA wasn't the only women alive at one point. She is just the only woman whose maternal line hasn't been broken. Haplogroups are groups that share common ancestors having the same single nucleotide polymorphism (which I talked a bit about earlier) which, together, form a genetic family tree where the haplogroups represent the branching areas of the tree. By mapping these haplogroups and seeing where and when these groups lived, researchers can determine migration patterns and how our first ancestors lived and evolved to create the world we now know. 

**//__Further Reading: __//**
[] - An interesting article about how the mtDNA of ancient skeletons was used to find the maternal histories and DNA clans of a certain population. [] - A web page that discusses mitochondrial and mtDNA diseases in humans and what happens when your mtDNA mutates. [] - A documentary entitles "The Real Eve" is based on the concept of Mitochondrial Eve and how her and the other first modern humans traveled out of East Africa. [] - An interactive web site that explores the ancestral human migrations patterns and how humans came to populate the earth.

**//__Sources Cited: __//**
[] [] [] [] []__ []