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Homologous vs Analogous Structures

Submitted by bthoole on Mon, 10/01/2018 - 17:30

Evolution is driven by natural selective processes but has no end goal or “perfect” structure or creation. The evolutionary development of species is driven by the opening of a niche and the fulfillment of that area to the best degree. Over time, this can result in structures that are similar in design or function between species. However, as taxonomists or biologists, it is important to understand the underlaying commonalities of the common ancestor of the similar species. The structure in question could either by the result of a shared common ancestor and the further development of the trait to fill a niche. These structures are known as homologous structures. An example of such structures would be the bones in the arm of a human and wing of a bat. On the surface they are different structures, but the bone shape and structure appear in similar shape and structure due to sharing a common ancestor. However, similar traits can arise because of convergent evolution, a process where evolutionary pressures cause for the need of the structure. The resulting structures from this kind of evolution are known as analogous structures. An example of this would be the wing of a bird and the wings of an insect. While they both developed wings, the structures themselves are derived from different evolutionary pressures. There is not a shared common ancestry between the two enclaves that would have given rise to wings in both.

Pavlov draft

Submitted by msalvucci on Mon, 10/01/2018 - 17:27

Classical conditioning occurs when stimuli that control reflexive behavior are paired together. Pavlov, the scientist that discovered this concept, came across this finding during his unrelated experiment with salivary glands. Although he was not a psychologist, this was a major finding that affected many aspects of physiology and psychology. His experiment consisted of quantifying saliva from a dog under conditions of food being in front of them or no food being in front of them. As he understood that the salivary glands involuntarily produce more saliva when a dog sees food in front of them, it came to his surprise when the salivary glands of the dogs started working without food in front of them. He came to realize that the dogs were anticipating food, so since they understood from repetition that sitting in the lab with Pavlov meant eating food, their salivary glands would produce saliva before the food was even brought out. This confused Pavlov at first; after more research he came to the conclusion that the neutral and conditioned stimuli paired together, thus creating the term ‘classical conditioning’. These stimuli can be innate and automatic, meaning that they happen spontaneously and do not need to be learned. This explains why human bodies can anticipate a reaction; for example, humans scrunch up when next to a person blowing up a balloon. They don’t know that the balloon will pop, but from past experience their body has learned to automatically react in a tense way. These concepts all fall under classical conditioning. 

Depth perception

Submitted by msalvucci on Mon, 10/01/2018 - 16:27

One of the most important concepts of eyesight is depth perception. Depth perception is what allows humans to distinguish 3-D objects from one another, and is what has helped humans evolve through time. In order to understand depth perception and how it develops in humans at a young age, experiments have been created to test this skill. Some tactics used are called ‘visual cliffs’, which are apparatuses that look like cliffs but are actually just small drop-offs. These cliffs cause no harm to the participant. If the participant is able to tell that there is a drop off, then they will avoid the edge of the cliff. However, if participants are unable to see the depth in the drop off, then they will walk on the glass where they would drop off. This experiment is used at different age groups to tell when depth perceptions comes into play throughout development. This experiment was also used to test depth perception of animals, including goats, chicks, dogs, rats, and lambs. The results of this experiment do not explain whether depth perception is a learned or innate skill; only some children walked across the cliff, and others were hesitant or did not at all. However, through other experiments it is evident that children must learn to understand depth perception through their experiences. 

Lungfish characteristcs and Naris

Submitted by mtracy on Mon, 10/01/2018 - 14:01

Nomally fish have an opening on thir snout called a naris. A naris is essentially the fish's nose and is packed with olfactory receptors. Water enters the naris, and leaves through a posterior naris. Some fish have this posterior naris in their mouth, where it is refered to as a choanae. The water will then enter the gills and exit the fish body that way. The lungifsh has a special case of Naris however, where both the posterior and rostral ends are within the mouth. It has been highly debated whether or not this may be refered to as a choanae.

African lungfish live in very wet areas which are prone to completely drying up. During this dry period, the lungfish will burrow into the ground and make a chamber for itself. It will then fill this chamber with large amounts of mucus, forming a coccoon like structure. The lungfish can live in thi cacoon fo months at a time, until another wet period begins. During these wet periods is when the lungfish nest and lay their eggs. The female will create a burrow and lay its eggs in a chamber, which will be filled with decaying plant material. The male lungfish guard the egg chamber. Due to the need for african lungfish to breath actual air, and not soley oxygen from water, while guarding these eggs the males will develop pelvic gills. Pelvic gills work in the opposite ways of respiritory gills. These gills will expell oxygen from the males body and oxygenate the surrounding water. In thi way the embryo's within the eggs will be able to breath more easily. The male lungfish will only have to surface for a gulp of air about once per hour.

draft methods

Submitted by amdicicco on Mon, 10/01/2018 - 12:24

A map was included in the figure to show where the web was located.  To avoid copyright issues, the map was taken as a screenshot from OpenStreetMap.org. To find the location, I typed in the closest permanent fixture near the bush which was Franklin Dining Hall. OpenStreetMap.org is not too detailed so I screenshotted a larger area to show more buildings, and the whole Permaculture Garden. This screenshot was wider than it was tall. The screenshot showed from the Shade Tree Lab past Clark Hall and the grass area past Franklin. Due to the large area covered in the map, I included a red circle which showed the exact location of the web on the bush. In order to not confuse the viewer, I also constructed a key in the bottom right-hand corner that showed the same circle and wrote location of web next to it. The key was placed onto a white background that was outlined in black to make it easily seen.

draft

Submitted by amdicicco on Mon, 10/01/2018 - 12:20

 

The figures that were created have similarities, but there are also many differences. Between figure 1 and figure 2 a common difference is with the labels. In the second figure the font is larger, darker, and a different type of font. When looking at the individual panels between the figures differences also arise. For example, in panel A the picture is taken at a different angle. Due to the different angle of the photograph figure 1’s includes a lot more of the plant’s pot. In panel B there are differences in the lighting. The difference causes a shadow over the plant.

Conditional Probability in Genetics

Submitted by fmillanaj on Mon, 10/01/2018 - 10:15

Conditional probability is applied when speific information about the outcome modifies te outcome. This idea is used in genetics when a certain factor about the outcome of crosses is known. This factor affects the genotypes of the offspring. Conditional probability is a step above normal crosses (which usually we know nothing about, other than the probability that a certain event will occur).

Week 4- PP, Methods

Submitted by aswan on Sun, 09/30/2018 - 22:52

I started by thinking about different locations spider webs mights be found on campus that would be easily accessible for any person. I decided to explore morrill to find spider webs as it is a easy building to access, yet has enough low foot traffic area for spider webs to be easily found. I walked up towards the garden/court yard from North Pleasant to get into Morrill.I entered Morrill 4 North through the door directly under the walkway that connects the two sides of Morrill. As I walked in I immediately looked to my right to see the map of Morrill, noting my location for future reference. I walked down the hallway going past the two double doors at the end of the hallway. I walked down the first set of stairs to the first landing that has two doors on its left and right that allow a person to leave Morrill. I inspected the stairs I had just walked down and I noticed that on the lowest stair there was a spider web on the left side of the stairs when facing up the stairs. I used a ten dollar bill as an object for scale, placing it on the floor of the landing next to the spider web with its width very close to the wall. The bill was angled so that Hamilton’s face was able to be seen, yet the bill appeared upside down in pictures due to it’s placement. I took several photos to ensure that I would have one that satisfied me, electing to use a picture that I used flashed in. After taking these pictures I walked up the stairs and took a picture of the stairwell  from the top landing closest to the door which I had entered initially. The picture included the stairs and the door closest to the stairs. After gathering the pictures I went to Livemaps and selected the location I was at on open street maps and took a screenshot of the map with the pinpointed location. After this I gathered the pictures and the screenshot into Inkscape. I organized the pictures into a square figures with the right half dedicated to the picture of the web, and the left side organized with the picture of the stairwell on top of the Livemaps screenshot.

The top left picture of the stairwell had the values of X= 0.394, Y= 219.951, W= 340.454, and H= 250, this picture also included an arrow pointing at the location of the spider web. The conditions of the line are X=245.877, Y=265.821, W=45.519, and H=46.193. This picture also contains the letter A in a white box, with black borders, at the top left and with the coordinates X=0, Y=428.781, W=42.0, and H=41.563. The bottom left screenshot of the map had the values of X=0.394, Y=0.0, W=340.454, and H=219.951. The picture includes a letter B in a white box, with black borders, at the top left and with the coordinates X=0.0, Y=178.781, W=42.9, and H=41.563 .The right picture of the spider web had the values of X=340.847, Y=0.0, W=375.300, and H=469.951. This picture too has a letter, the letter C, in a white box with black borders with the coordinates X=340.454, Y=428.781, W=42.0, and H=41.563.

Week 4- Methods Draft 5

Submitted by aswan on Sun, 09/30/2018 - 22:52

I started by thinking about different locations spider webs mights be found on campus that would be easily accessible for any person. I decided to explore morrill to find spider webs as it is a easy building to access, yet has enough low foot traffic area for spider webs to be easily found. I walked up towards the garden/court yard from North Pleasant to get into Morrill.I entered Morrill 4 North through the door directly under the walkway that connects the two sides of Morrill. As I walked in I immediately looked to my right to see the map of Morrill, noting my location for future reference. I walked down the hallway going past the two double doors at the end of the hallway. I walked down the first set of stairs to the first landing that has two doors on its left and right that allow a person to leave Morrill. I inspected the stairs I had just walked down and I noticed that on the lowest stair there was a spider web on the left side of the stairs when facing up the stairs. I used a ten dollar bill as an object for scale, placing it on the floor of the landing next to the spider web with its width very close to the wall. The bill was angled so that Hamilton’s face was able to be seen, yet the bill appeared upside down in pictures due to it’s placement. I took several photos to ensure that I would have one that satisfied me, electing to use a picture that I used flashed in. After taking these pictures I walked up the stairs and took a picture of the stairwell  from the top landing closest to the door which I had entered initially. The picture included the stairs and the door closest to the stairs. After gathering the pictures I went to Livemaps and selected the location I was at on open street maps and took a screenshot of the map with the pinpointed location. After this I gathered the pictures and the screenshot into Inkscape. I organized the pictures into a square figures with the right half dedicated to the picture of the web, and the left side organized with the picture of the stairwell on top of the Livemaps screenshot.

The top left picture of the stairwell had the values of X= 0.394, Y= 219.951, W= 340.454, and H= 250, this picture also included an arrow pointing at the location of the spider web. The conditions of the line are X=245.877, Y=265.821, W=45.519, and H=46.193. This picture also contains the letter A in a white box, with black borders, at the top left and with the coordinates X=0, Y=428.781, W=42.0, and H=41.563. The bottom left screenshot of the map had the values of X=0.394, Y=0.0, W=340.454, and H=219.951. The picture includes a letter B in a white box, with black borders, at the top left and with the coordinates X=0.0, Y=178.781, W=42.9, and H=41.563 .The right picture of the spider web had the values of X=340.847, Y=0.0, W=375.300, and H=469.951. This picture too has a letter, the letter C, in a white box with black borders with the coordinates X=340.454, Y=428.781, W=42.0, and H=41.563.

 

Week 4- Methods Draft 4

Submitted by aswan on Sun, 09/30/2018 - 22:51

I started by thinking about different locations spider webs mights be found on campus that would be easily accessible for any person. I decided to explore morrill to find spider webs as it is a easy building to access, yet has enough low foot traffic area for spider webs to be easily found. I walked up towards the garden/court yard from North Pleasant to get into Morrill.I entered Morrill 4 North through the door directly under the walkway that connects the two sides of Morrill. As I walked in I immediately looked to my right to see the map of Morrill, noting my location for future reference. I walked down the hallway going past the two double doors at the end of the hallway. I walked down the first set of stairs to the first landing that has two doors on its left and right that allow a person to leave Morrill. I inspected the stairs I had just walked down and I noticed that on the lowest stair there was a spider web on the left side of the stairs when facing up the stairs. I used a ten dollar bill as an object for scale, placing it on the floor of the landing next to the spider web with its width very close to the wall. The bill was angled so that Hamilton’s face was able to be seen, yet the bill appeared upside down in pictures due to it’s placement. I took several photos to ensure that I would have one that satisfied me, electing to use a picture that I used flashed in. After taking these pictures I walked up the stairs and took a picture of the stairwell  from the top landing closest to the door which I had entered initially. The picture included the stairs and the door closest to the stairs. After gathering the pictures I went to Livemaps and selected the location I was at on open street maps and took a screenshot of the map with the pinpointed location. After this I gathered the pictures and the screenshot into Inkscape. I organized the pictures into a square figures with the right half dedicated to the picture of the web, and the left side organized with the picture of the stairwell on top of the Livemaps screenshot.

The top left picture of the stairwell had the values of X= 0.394, Y= 219.951, W= 340.454, and H= 250, this picture also included an arrow pointing at the location of the spider web. The conditions of the line are X=245.877, Y=265.821, W=45.519, and H=46.193. This picture also contains the letter A in a white box, with black borders, at the top left and with the coordinates X=0, Y=428.781, W=42.0, and H=41.563.

 

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