Vanessa+M.

**__Post #1: ADHD & DNA __** //April 2016//

 The first semester of my grade 10 year was probably one of the toughest times of my life. Unlike years prior, paying attention during class was completely impossible for me. During math especially, my energy was devoted to drawing or socializing and never to watching the board or truly listening to the lesson being taught. As a result, my marks were unbelievably low. I wanted to alter my ways more than anything, but as odd as it may sound, I didn't feel as though I was in control of my own tendencies. It was as if my mind had its own agenda. After many months, the root of my problems was finally unearthed and during December of 2013, I was officially diagnosed with attention deficit disorder (ADD). Since then, I have managed to find a multitude of ways to cope with ADD, but I'm still puzzled by how I came to host it in the first place. Unfortunately, I'm not the only one left wondering; the whole world has been struggling to determine what causes ADHD since it was first recognized in circa 1960. It's a tough case to crack and the vast majority of ideas pertaining to the causes still lay unconfirmed, however, there have been new studies released that indicate that there is likely a connection between ADHD and our genes. If this is the case, those affected by it may not be in complete control of their tendencies after all...   ==__WHAT IS ADD/ADHD? __ ==   Attention deficit disorder (ADD) is a neurological disorder which is characterized by chronic inattention and distractibility. It is usually diagnosed in children and adolescents, particularly boys, and it is said that approximately 11% of all American children are affected by it. When discussed, it is often referred to as attention deficit hyperactivity disorder (ADHD) as many consider "ADD" to be an outdated term, however there is in fact a difference between the two. People with ADHD tend to either solely experience hyperactivity/impulsivity or have a combination of inattention and hyperactivity, while those with ADD usually only have trouble with attention. That being said, the term that I will use the most for the remainder of this study will be ADHD, as it is more inclusive of all three general types.

 ==__SYMPTOMS __ == <span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;"> <span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;"><span class="TextRun SCX57041117" style="font-family: Arial,sans-serif; font-size: 11pt;"> Symptoms of ADHD vary dramatically depending on the individual and which type of ADHD they are diagnosed with. <span class="EOP SCX57041117" style="background-color: transparent; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt; text-align: justify;"> It also must be noted that as those with ADHD mature, symptoms may change. Below is a photo sharing ideas of how this may happen.
 * <span class="TextRun SCX57041117" style="background-color: transparent; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt;">Those with <span class="NormalTextRun SCX57041117" style="background-color: inherit; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt;">__inattentive ADHD (ADD)__ <span class="TextRun SCX57041117" style="background-color: transparent; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt;"> tend to have short attention spans, weak listening skills, an inability to understand or follow given instructions, a tendency to procrastinate, bad memories, a habit of over-thinking things and they lack motivation.
 * <span class="TextRun SCX57041117" style="background-color: transparent; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt; text-align: justify;">Those with <span class="NormalTextRun SCX57041117" style="background-color: inherit; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt; text-align: justify;">__hyperactive-impulsive ADHD__ <span class="TextRun SCX57041117" style="background-color: transparent; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt; text-align: justify;"> usually experience extreme restlessness and find it difficult to sit still for extended periods of time. Fidgeting, talking too much/talking at inappropriate times, interrupting frequently and general constant motion, as if driven by a motor, are also symptoms that one may face.
 * <span class="TextRun SCX57041117" style="background-color: transparent; color: windowtext; font-family: Arial,sans-serif; font-size: 11pt; text-align: justify;">If someone has a __combination__ of these disorders, they consequently experience some combination of both types of symptoms.

<span style="background-color: #ffffff; display: block; font-family: Arial,sans-serif; font-size: 14.6667px; text-align: justify;"> In terms of what ADHD does neurologically, those with the disorder generally have lower levels of dopamine, and some research has shown that affected children tend to have several regions of the brain (pre-frontal cortex, cerebellum, striatum, etc.) that are somewhat smaller than they should be.Below is a comparison of two brain scans; one of someone with ADHD and one of someone without.Further down is a more detailed photo which indicates which areas of the brain are most affected and highlights several other ways that the brain is physically affected by this disorder. <span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;"> <span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;">

<span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;">

==<span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;">__<span class="TextRun SCX57041117" style="font-family: Arial,sans-serif; font-size: 11pt;">CAUSES __ == <span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;"> <span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;"><span class="TextRun SCX57041117" style="font-family: Arial,sans-serif; font-size: 11pt;"> As stated earlier, the true cause of ADHD is still unknown, however scientists do know that there's definitely more than one factor involved. Brain/head trauma and fetal exposure to toxic substances are two ideas that are actively being studied, but the idea that ADHD may exist in DNA has scientists conducting research like none other. One of the most interesting reasons for why they believe that ADHD may be genetic is due to the results from studies that have been conducted on fraternal and identical twins. The idea behind the study of twins was that, since identical twins share the same genetic information, the probability of them both possessing ADHD should be higher than the probability of fraternal twins, as they do not have the exact same genetic information. Despite the fact that the studies were performed by different researchers at various locations around the world, all of the results were remarkably consistent with both each other and the general hypothesis. One of the studies that took place in Australia involved 1938 families that had twins and/or siblings. At the end of the study, it was found that 82% of identical twins affected by ADHD both experienced the disorder, compared to only 38% of fraternal twins. Another, less detailed, study which points to ADHD being hereditary has shown that one-third of all fathers who have experienced ADHD at some point of their lives produce children with the disorder. In fact, it's been proven that a huge amount of affected children have at least one closely-related relative who has it as well. <span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;"> <span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;"><span class="TextRun SCX57041117" style="font-family: Arial,sans-serif; font-size: 11pt;"> Meanwhile, there are many existing studies taking place as we speak. Particular groups in California and the Netherlands have both recently found evidence that linkage on chromosomes may exist; genes that are very close to each other on the chromosome which may be inherited together. Theoretically, they believe that it may not only explain how ADHD is genetic, but also many other disorders, so they are working around the clock and studying the DNA of various families to find out if this is in fact correct and which genes are responsible for creating ADHD. To give an idea of what linkage is, here is a simple explanation:

<span style="background-color: transparent; color: windowtext; text-align: justify; vertical-align: baseline;"><span class="TextRun SCX57041117" style="font-family: Arial,sans-serif; font-size: 11pt;">The information in the following video has further information pertaining to some of the studies that have been taking place and shares news that the regions of the chromosomes that seem to be carrying the genes for ADHD overlap with the same regions that have relations with autism. (Further information on this was difficult to come by and therefore was not discussed earlier.)

media type="youtube" key="3NlaekvCZ48" width="560" height="315"

__FURTHER READING:__
<span style="background-color: transparent; color: windowtext; text-decoration: none; vertical-align: baseline;">[|__http://www.additudemag.com/channel/adhd-symptoms-diagnosis/index.html__] <span class="TextRun SCX141632683" style="font-family: Arial,sans-serif; font-size: 11pt;">(The website in general gives great information on every aspect of ADHD, from old misconceptions to new research and everything in between.) <span style="background-color: transparent; color: windowtext; text-decoration: none; vertical-align: baseline;">[|__http://psychcentral.com/lib/causes-of-attention-deficit-disorder-adhd/__] <span class="TextRun SCX141632683" style="font-family: Arial,sans-serif; font-size: 11pt;">(Discusses the link between ADHD and genes and offers many other ideas for potential causes.) <span style="background-color: transparent; color: windowtext; text-decoration: none; vertical-align: baseline;">[|__http://psychcentral.com/lib/the-genetics-of-adhd/__] <span class="TextRun SCX141632683" style="font-family: Arial,sans-serif; font-size: 11pt;">(Offers even more detailed information on studies that have been carried out to prove the gene-ADHD link.) <span style="background-color: transparent; color: windowtext; text-decoration: none; vertical-align: baseline;">[|__http://www.lifehack.org/articles/lifestyle/20-things-remember-you-love-person-with-add.html__] <span class="TextRun SCX141632683" style="font-family: Arial,sans-serif; font-size: 11pt;">(Helpful source for those who live with people affected by ADHD. Provides information on how their minds work/general tendencies.)

//SOURCES://
<span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;"> <span style="background-color: transparent; color: windowtext; text-decoration: none; vertical-align: baseline;">[|__http://www.healthline.com/health/adhd/difference-between-add-and-adhd#Overview1__] [|__http://www.additudemag.com/adhd/article/688.html__] [|__http://www.everydayhealth.com/adhd-awareness/an-adhd-timeline.aspx__] [|__http://www.webmd.com/add-adhd/guide/types-of-adhd__] [|__http://www.myadhd.com/causesofadhd.html__] [|__http://www.additudemag.com/adhd/article/653.html__]

<span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;"> <span style="background-color: #ffffff; display: block; font-family: 'Segoe UI',Tahoma,Verdana,sans-serif; font-size: 8px;">

<span style="font-family: Arial,sans-serif; font-size: 14.6667px;">_ _

=__**Post #2: Tourette Syndrome: A Neurological Disorder**__=

//May 2016//
I was first introduced to Tourette Syndrome many years ago through a TV show that covered the life of a British man who’d been suffering with the disorder since childhood. It was simultaneously inspiring and devastating to follow his struggle toward a normal life. However, the program also opened my mind to the reality that the human species is susceptible to a plethora of inconceivable, uncontrollable conditions, which was an idea that I honestly found frightening at that age. As time has gone by, I’ve obviously grown accustomed to this concept and my initial fear has since turned into curiosity, especially when it comes to Tourette’s, as that is the disorder that triggered my paradigm shift. That being said, I’ve never actually taken the time to research TS and learn more about it, so I think that this assignment gives me the perfect opportunity to finally do that.

__WHAT IS TOURETTE SYNDROME?__
Tourette Syndrome (also known as Tourette’s Syndrome, Tourette’s or TS) is a neurological disorder that is characterized by sudden, recurrent, involuntary vocalizations and movements. These are known as tics. To be diagnosed with TS, individuals must possess at least one phonic tic and two or more motor tics. Furthermore, these tics must have been endured for a minimum of one year. It is believed that just under 1% of the world’s population meets these requirements, with prevalence being three times higher in males than in females. Tourette’s is a condition that affects all ethnic groups, yet interestingly enough, studies have shown that it is surprisingly rare among Sub-Saharan Africans and those of African descent. hink that this assignment gives me the perfect opportunity to finally do that.

__SYMPTOMS__
The number one symptom of Tourette Syndrome are phonic and motor tics; the diagnosis of the condition revolves around their possession. However, the possibilities are endless when it comes to the tics that one can experience, making each case of Tourette’s unique. This becomes even more relevant when you consider the fact that the severity and frequency of TS symptoms not only varies from person to person, but throughout the course of their lives, as well. In fact, it is not uncommon for tics to disappear for up to three months, nor is it unlikely that individual tics will change over time.

//The graph above illustrates how the severity of TS symptoms usually changes over a lifetime.//

Tics tend to be classified as either ** simple or complex **. If there is a limited amount of muscle groups being used or sounds being produced, then it is deemed to be a ** simple tic**. Some of the most common and ** simple phonic tics** include excessive, overemphasized throat-clearing, humming, sniffing, yelling or screaming, barking and throat-clearing. A few examples of common, ** simple motor tics** would be sudden facial grimaces, eye blinking/movements, head jerks, shrugging, and licking of lips. Meanwhile, tics are said to be ** complex ** if they involve a number of muscle groups or if a complicated sound/phrase is generated. Any immediate combination of tics, for example jumping then twisting, are also considered ** complex **.
 * Complex phonic tics** encompass stuttering, echoing of oneself or of others, animal sounds, changes in pitch or volume and, the most stereotypical Tourette’s tic, coprolalia.*
 * Complex motor tics** may include, but are not limited to, pulling at clothes, poking, kicking, kissing, imitating the actions of others, skipping, walking on toes, and self-harm.

//To the left is a chart which provides additional examples of tics.//


 * Coprolalia is the utterance of a socially inappropriate word/phrase. Although it affects less than 10% of people who are diagnosed with Tourette’s, it has generated the largest stigma for the condition.

It is important to note that tics are not the only symptom that people with Tourette’s experience. Many are plagued by other neurobehavioral disorders such as ADHD, obsessive-compulsive disorder, depression, anxiety and/or learning impairments.

__CAUSES__
Tourette Syndrome is a genetic condition. It is polygenic, given that there are a combination of genes that determine whether or not the condition is present, but we have yet to piece together the different genes. It is also thought that prenatal environmental factors such as the mother’s caffeine/alcohol/tobacco intake, stress levels, vomiting, etc. may play a role in whether or not an infant is born with TS. The research behind both of these causes and is still ongoing.

__**DIFFERENCES IN THE BRAIN**__
Scientists are still studying all of the specifics of what makes affected nervous systems unique, however, they can agree that the tics which TS individuals experience are a result of anomalies in the brain. Studies in brain imaging have not only backed up this idea, but illustrate that the main differences may lie in the corticalstriatal-thalamal-cortical circuitry of the brain. Consequently, the thalamus, basal ganglia and frontal lobes of the cerebral cortex are all being monitored, along with the neurotransmitter dopamine. //This photo indicates which regions of the brain I am referring to.//


 * The **thalamus** relays information pertaining to sensors and motors to the cerebral cortex and the brain stem. Disturbances with the thalamus could definitely have something to do with the tic symptoms of TS.
 * The **basal ganglia** works in the coordination of movement and is described as being a bit like a brake when it comes to preventing unwanted/unintentional movements and sounds. Disorders in this region of the brain could, as one could predict, lead to sudden, sporadic, inadvertent movements.
 * The **frontal lobes** are in charge of organizing and executing movement, thought and speech. Scientists are specifically cracking down on the relation that they have with the basal ganglia, for it seems that when the frontal lobes in TS patients attempt to signal to the basal ganglia to stop certain movements, there is, at times, an abnormality. This may have a heavy influence on the occurrence of tics, both in people with Tourette’s and in those with other tic-related disorders.
 * Excessive amounts of **dopamine** and the volume of other neurotransmitters are other factors that are being explored as possible contributors to Tourette Syndrome. Dopamine helps regulate emotions and movement, therefore a change in the amount of dopamine could alter its abilities, especially within the brain of a Tourette’s-positive individual. It has already been shown that low levels of dopamine may play a role in causing Parkinson’s disease (which involves slowed movement) so it’s worth looking at the opposite end of the spectrum, especially when discussing Tourette’s, which is defined by quicker movements.

// Above is a chart that compares brain scan images of a TS brain before and while experiencing a tic. //

The video that I have embedded below talks a lot about questionable techniques used to treat Tourette Syndrome, but it was honestly the best video that I could find on the disorder. Treatment aside, it talks about the different regions of the brain that are affected as well as shows someone experiencing tics and provides viewers with an idea of the limitations which TS patients experience. media type="youtube" key="QH28i7LbbxM" width="560" height="315"

__FURTHER READING__
[Provides information on the treatment method that was discussed in the video & further information on Tourette's.] [This site is full of detailed information concerning TS & it covers many other corners, such as suppressing tics & related conditions.] [An article written by Johanna Elsemore, a woman who has Tourette Syndrome. It is written from her perspective, & shares both her story & her views on TS.] [A variety of treatment options for TS are explored on this website.]
 * [|http://tourette.org/Medical/DBS.html]
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__REFERENCES__
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=__**Post #3: Harvest-Induced Evolution**__=

//June, 2016//
For as long as I can remember, I’ve been an unofficial naturalist. While other kids my age were watching cartoons and playing with plastic figurines, I insisted on watching Animal Planet and catching frogs. I absolutely loved the great outdoors and every little detail about nature. But as time passed and as I grew older, I gradually became exposed to environmental issues, causing my bubble of childish belief that nature was everlasting, unrivaled and well respected to eventually decompose. As I entered my double digits, my attention parted ways with the beauty of nature and began to refocus on the greater problems that it faces, such as whaling in the Southern ocean, pollution, nuclear testing and deforestation. I heavily questioned why people don’t change their ways, even when evidence of a plight is undeniable. Today, I understand many of the motives behind the destructive actions of our population and I realize that one of the leading factors preventing us, as a whole, from changing our ways is a lack of information. Much of the world is naïve to the details and solutions for solving many environmental issues and, even more so, the vast majority of people are not conscious about just how powerful of an effect our actions have on our surroundings. For this reason alone, I have decided to explore an environmental issue that we are just beginning to unearth; one that is directly linked to our actions; something that we may have never considered would occur. My final wikipost will discuss how human behavior and societal standards, particularly through hunting and fishing, are driving certain species to evolve unintentionally.

__**Laws of Selection**__
Before diving into the topic of human behavior causing selective pressure through predation, it is important to recapitalize on the laws of selection. It is well known that natural and sexual selection are responsible for pushing species to evolve. In order to flourish and survive, organisms must be well adapted to their environment. If changes occur, the species has to either conform or die. The pressures that could potentially be placed upon a species (or even a population, in some cases) are endless; nevertheless, they may all be categorized as a geographical change, a behavioral change or a temporal change. Another thing worth noting is that evolution is a constant occurrence. Even if the changes are miniscule, species are always evolving. Microevolution is when species experience small changes over short periods of time while macroevolution is when organisms change dramatically over a long period of time. No matter which time frame you pick, you will witness evolution. If evolution is constantly occurring, then that leaves no room for genetic stability. The Hardy-Weinberg law states that in order for a species to experience genetic stability, the requirements are: It is impossible for a species to meet all of this criteria at once and if you entertain the idea of natural catastrophes, (im)migration, etc, then you’ll find that genetic stability is a laughing matter.
 * A large population size.
 * Isolation from other populations.
 * No net mutations.
 * Random mating/no sexual selection.
 * No natural selection for all individuals are equally suited for their environment.

__**Selection by Humans**__
The way in which we may manipulate evolution in species stems from what we do, for through our behavior and beliefs, we apply pressure to species, directly and indirectly forcing adaptive changes to occur. “Artificial selection” is the term that is used when humans intentionally select certain individuals to breed over others due to possession of admirable, but not always beneficial, qualities. This method is primarily used in farming, agriculture and domestication, yet it can be argued that any given case where an organism’s ability to survive could be altered by a human act is artificial selection, for the pressures being applied against the species are not natural. This would mean that things such as hunting, fishing and resistance to human developments are also artificial selection. As of yet, no species/populations that have undergone artificial selection have become a new species, but given enough time and pressures, it could potentially be achieved, especially among uncontrolled organisms that are making alterations due to unintentional selection pressures that we have presented, such as anti-biotic resistant bacteria. In their case, humans are not picking and choosing from all of their qualities, as in farmed organisms, but are placing a pressure or barrier in their way which is forcing them to get around it. There seems to be a very blurry line between what is considered artificial selection and what is, in fact, natural selection, especially when considering unintentional versus intentional actions, direct and indirect impact on ecosystems and the fact that many of the pressures that we apply (ex: hunting) already occur in nature, although somewhat less dramatically and not all originating from one organism/source. Determining where, exactly, to draw the line between both forms of selection is not how I intend to continue my wikipost. Until this point, my goal was simply to determine that other species are changing due to human acts. Now, I will proceed to explore how hunting and fishing in particular can affect species and I will provide a specific case where an identifiable human action is unintentionally causing organisms to select for different traits and/or characteristics.

__**How Species Are Affected by Harvesting**__
Be it artificial selection or something greater, it’s undeniable that humans have the ability to shape the living world around them in unimaginable ways. One major way that people are proven to be influential is through predation/harvesting. There is no denying that we are super predators. We hunt and fish a variety of different species at degrees never seen before and always select individuals with the most admirable qualities. The organisms that we leave behind are usually few in numbers and are far from our societal standards. According to one study, our presence as a super predator and our pickiness for the individuals that we do harvest is causing a dramatic spike in the rate that our prey species are developing. It has been proven that the body sizes and reproduction strategies of many organisms that we primarily target are experiencing rapid fluctuations and changes, occurring nearly 300 times faster than they would naturally. Another report that focused on 29 different species across 40 different geographic locations was able to back up this study. The general conclusion that this report made stated that in populations that are harvested and hunted, organisms tend to be, on average, 20% smaller in size than generations before and they reach sexual maturity 25% earlier. Not to mention, all of this was occurring within only a couple of lifetimes. But why would harvesting result in smaller body sizes in organisms? It’s simple. As mentioned prior, when we hunt and fish, we do so on a grand scale, taking out a large amount of organisms. Not just that, but the organisms that we leave behind are those which do not boast admirable traits, for they are small, weak, etc. This has a direct effect on the gene pool of the prey species. If only the small and weak individuals are left in a population, then the only breeding that will occur will be between small and weak individuals, resulting in smaller and weaker offspring and so on and so forth. By taking only the biggest and best organisms out of a population, we also take away the potential for future generations to comprise of big organisms too, for there are no longer as many big organisms left in the population that can pass on their traits. Although hunting is not completely commercial, many people partake in it, and in trophy hunting, which is what causes these great changes to occur in game/prey species. //In this graph, a selective pressure is added to one side of a population (in the case of humans and prey species, larger individuals are pressured). The population (having had it's larger individuals selected against) adapts for the opposite extreme (in this case, smaller body types) and changes to avoid the selective pressure.//

Harvesting game animals based on their size is extremely problematic. For a variety of species, especially those that we focus on ourselves, natural pressures select for larger individuals. The larger and stronger the individuals are, the better chance that they have at reproducing. If we, humans, come in and start applying pressure on the more successful individuals, and especially if the pressures that we are applying are much more immediate than nature's, then we will see the population, or even the species, begin to fold back and attempt to grow smaller/contradict nature. If they are selecting for a size that nature has been trying to select against, than many problems will arise, and the species will turn out being just large enough that it can withstand nature and just small enough that humans are not interested, however, it will likely never flourish, especially if, one day, the harvest-induced pressure is lifted. //Nature applying pressure on one side for smaller individuals, harvest applying pressure on the other for larger individuals.//

As for why organisms are reaching sexual maturity earlier, there are a number of ways that we are contributing to this change. One of the most extreme ways that this is occurring has to do with the amount of organisms that we harvest. The more individuals that we take out of a location, the less pressure their food sources receive, therefore they begin to blossom and the remaining organisms are left with a plentiful amount of food. Because of plasticity, the reproduction age of certain species, such as some types of fish, has a direct connection with the amount of food available. When we take out a large amount of organisms and leave an abundance of food in our wake, the remaining individuals feast and some species experience a forwards leap in their sexual maturity age. //This graph could accurately display what is occurring with smaller bodied fish. As more and more large fish are taken out of the equation, there are more resources provided for smaller fish, who are able to grow in numbers until the carrying capacity is maintained. (This is a rocky idea but I hope you see where I'm going with this.)//

When it comes to fish in particular, scientists are also researching another key reason for why sexual maturity may be achieved earlier. It is still a rocky concept, but there is speculation that the fish that express genes causing later sexual maturity may be harvested before they breed, removing, over time, the genes for later maturity from the gene pool. Not matter the reason behind what is causing reproduction to occur earlier in some organisms, the results are not good. It has been proven that although creatures reproduce at younger ages, they are fertile for a much shorter period of their lives, and therefore produce fewer offspring than they would had they not experienced some form of pressure. Harvesting/predation is only one way that humans are able to affect the genes of populations and even species without general intent to do so. There are a variety of other ways that humans leave their mark unintentionally, like through pollution, habitat destruction, urbanization, domestication, drug resistance etc. The harvest of species by humans is the only type that I have decided to explore, and further reading on alternative ways that we influence change in allele frequency in species can be found at the bottom of this post. Along with more information on alternative ways, you will also find links containing information on several more manners that harvesting through hunting and fishing can leave a mark on populations.

Sexual Maturity || Increased mortality. || Sexual maturity at earlier age & size. Reduced fertility. || Reduce harvest mortality or modify selectivity of harvest. || Morphology, Sexual Dimorphism. || Selective harvest of larger or more distinctive individuals. || Reduced growth rate. Attenuated phenotypes. || Reduce selective harvest of large or distinctive individuals. || Weapons (horns, tusks, antlers, etc.) || Trophy hunting. || Reduced weapon size or body size. || I mplement hunting regulations that restrict harvest based on size or morphology of weapons under sexual selection. || seasonally early or late reproducers. || Altered distribution of reproduction (truncated  or altered seasonality). || Harvest throughout reproductive season. || active or aggressive or bolder (more vulnerable to  predation) individuals. || Reduced boldness in foraging or courtship behavior, potentially reduced productivity. || Implement harvest methods less likely to impose selection on activity or aggressive behavior. || with more predictable migration patterns. || Altered migration routes. || Interrupt harvest with key time & area closures tied to primary migration routes. || //Above is a chart found on the website:// //[|http://www.nap.edu/read/12692/chapter/10#131]// //I found it extremely interesting, for it summarizes the key ways that hunting and fishing leave their mark on certain organisms. Although I only focused on changes to body size and sexual maturity, this chart will hopefully give you an idea of what other ways human predation techniques and societal standards are imposing on the structures of prey species.// //Better yet, it provides information on ways that we can resolve some of these issures.//
 * **TRAIT** || **SELECTIVE ACTION** || **RESPONSE** || **REMEDY** ||
 * Age & Size at
 * Body Size or
 * Sexually Selected
 * Timing of Reproduction || Selective harvest of
 * Behavior || Harvest of more
 * Dispersal/Migration || Harvest of individuals

To finish off, here are two graphs showing what is going on concerning sexual maturity and body sizes in prey species. //In the first graph, we look at harvesting-induced evolution resulting in changes to sexual maturity age. As you can see, it is often faster than evolution caused through natural mortality. Changes that are induced by harvest-related pressures occur much more quickly than true evolutionary changes, but natural evolutionary changes are expected to last much longer, especially when harvest-induced mortality is removed.// //In the second graph, we see how body size is affected by the pressure of harvesting. The pressures usually select against body sizes that would be the most fit for their environment, leaving individuals who aren't as well equipped for their environment, thus creating a weaker population. Activities that could produce such changes could include trophy hunting and trawling (for smaller organisms are not as vulnerable to trawling).//

To top off my post, here is a very interesting video that shares the story of the cod fish. Due to overfishing, cod have experienced dramatic reductions in their body size in an attempt to escape the harvest-induced pressure. media type="youtube" key="DEtKj88UPmM" width="560" height="315"

__**Further Reading**__
[] [contains further information on harvest-related pressures/evolution] [] [provides details on a variety of human-induced selective pressures] [] [has tons of information about human's hand in evolution and offers a plethora of real-time examples, from the peppered moth to tusk-less elephants to fishing and more] [|https://news.stanford.edu/2015/02/19/body-size-evolution-021915/] [discussion on general changes in body size through natural occurrences]

__**Sources**__
[] [] [] [|http://www.nap.edu/read/12692/chapter/10#131][] <span style="display: block; height: 1px; left: 0px; overflow: hidden; position: absolute; top: 2541.5px; width: 1px;">Tourette Syndrome is a genetic condition. It is polygenic, given that there are a combination of genes that determine whether or not the condition is present, but we have yet to piece together the different genes. It is also thought that prenatal environmental factors such as the mother’s caffeine/alcohol/tobacco intake, stress levels, vomiting, etc. may play a role in whether or not an infant is born with TS. The research behind both of these causes and is still ongoing. ee months, nor is it unlikely that individual tics will change over time. Tics tend to be classified as either simple or complex. If there is a limited amount of muscle groups being used or sounds being produced, then it is deemed to be a simple tic. Some of the most common and simple phonic tics include excessive, overemphasized throat-clearing, humming, sniffing, yelling or screaming, barking and throat-clearing. A few examples of common, simple motor tics would be sudden facial grimaces, eye blinking/movements, head jerks, shrugging, and licking of lips.

Meanwhile, tics are said to be complex if they involve a number of muscle groups or if a complicated sound/phrase is generated. Complex phonic tics encompass stuttering, echoing of oneself or of others, animal sounds, changes in pitch or volume and, the most stereotypical Tourette’s tic, coprolalia.* Complex motor tics may include, but are not limited to, pulling at clothes, poking, kicking, kissing, imitating the actions of others, skipping, walking on toes, and self-harm. Any immediate combination of tics, for example jumping then twisting, are also considered complex. It is important to note that tics are not the only symptom that people with Tourette’s experience. Many are plagued by other neurobehavioral disorders such as ADHD, obsessive-compulsive disorder, depression, anxiety and/or learning impairments.
 * Coprolalia is the utterance of a socially inappropriate word/phrase. Although it affects less than 10% of people who are diagnosed with Tourette’s, it has generated the largest stigma for the condition.