User:Jcbarron24/sandbox

Week 3: Evaluate Wikipedia

Article Evaluation: Conditioned Taste Aversion

The Wikipedia article I chose to evaluate for this weeks assignment was Conditioned Taste Aversion. This article gave a fair explanation of what taste aversion is, did not contain any obvious biases and made references to a number of important scientific studies relevant to the topic. However, there were also a lot of major issues with this article that should be addressed.

The main issue with this article, in my opinion, is the lack of references. There is a note from Wikipedia at the top of the article dated December 2006 that indicates more citations are required for verification. The entire article is roughly 1500 words long and only contains six references; two of them being references to definitions in the Oxford dictionary. This is unfortunate since the article explains many significant studies on taste aversion and it would have been useful for the reader if the sections on these research projects had proper citations for verification and further readings. On a positive note, the few references that are included in the article are correctly formatted, the links included for these references work and the references are from legitimate sources. Also the cited information in the article does seem to be supported by the references.

Most of the information contained in the article appears to be relevant to the topic, with a few exceptions. There are a lot of repetitive, common examples of taste aversion in humans (sick from eating raw sushi, food poisoning from steak, etc.) that could of been taken out for conciseness. Also the section "Stimulus Generalization" gets a bit off topic towards the end when it discusses factors of stimulus generalization in situations outside of taste aversion. The section "Garcia's Study" is also hard to understand towards the end and should be reworded for clarity.

The talk page for this article is fairly lengthy and overall the reviews for this article are not supportive. The first section of the talk page suggests that the article should be merged with Conditioned Taste Aversion, which I am assuming the author did since that is now the name of their article. The next section of the talk page sounds like it was made by someone with a psychology background and a good understanding of learning processes. The person commenting explains why it is incorrect to class taste aversion as classical conditioning, and why taste aversion and conditioned taste aversion are not the same thing. This section also mentions that the article should include a statement about new research that has shown how vampire bats do not develop taste aversions, which sounds interesting and could potentially lead into a section about why taste aversion is not always beneficial for animals. The third section of comments discusses most of the same issues as in the previous section, was informative and also sounds like it was written by someone with a background in psychology. The final comment on this talk page says that the last part of the section "Garcia's Study" should be explained better, which I agree with. This article is rated poorly and I agree with the reviews left from other users in the talk page. Also this article is not a part of any WikiProjects.

In class we discussed the concept of classical conditioning and Garcia and Koelling's research on taste aversion in rats. Our class discussions differ from the information presented in this article. In class we discussed how Garcia's study challenged psychologists belief that learning dominated over life history in terms of how these factors affect behaviour in animals and this information is not mentioned in this article. It would of been helpful if the author of this article had a better explanation of classical conditioning and backed up their statement that Garcia's findings "did not follow the basic principles of classical conditioning". This could have been done with a short explanation of the nature/nurture controversy and how these findings supported the importance of life history.

Week 6: Finalize your topic/Find your sources and Draft your article

Topic: Brachiation

Notes for improvement of existing article:

-Section titled Types of Brachiation

-Differentiate between two types of brachiation in hylobatids: continuous-contact and rhecochetal

-Section titled Models of Brachiation

- Explain comparison between movement of a pendulum and brachiation of hylobatidae (Gibbons and Siamangs). The costs and benefits of this form of movement. Experiment by Michilsens.

-Section titled Evolution of Brachiation

-Explain first known occurrence of brachiation

-Expand on how brachiation could have lead to human bipedalism and mention relevant theories such as the "vertical climbing hypothesis"

List of relevant sources:

-Gebo. D.L. (1996). "Climbing, Brachiation, and Terrestrial Quadrupedalism: Historical Precursors of Hominid Bipedalism". American Journal of Physical Anthropology. 101 (1): 55.

-Michilsens. F. (2011). "How pendulum-like are siamangs? energy exchange during brachiation".

-Oka. K. (2010). "Brief communication: three-dimensional motion analysis of hindlimb during brachiation in a white-handed gibbon".

-Bertram. J.E.A. (2004). "New perspectives on brachiation mechanics".

Week 10: Complete first draft of article

Adding to the already existing article Brachiation

Add additional picture

Additional Information/Changes to Existing Intro
(Continuing from the sentence "Some New World species also practice suspensory behaviours by using their prehensile tail, which acts as a fifth grasping hand."):

Evidence has shown that the extinct ape Proconsul from the Milocene of East Africa developed an early form of suspensory behaviour, and was therefore referred to as a probrachiator. Upon further observations and more in depth understandings of the anatomy and behaviour of primates, the terms semibrachiator and probrachiator have largely fallen out of favour within the scientific community. Currently, researchers classify hylobatids (gibbons and siamangs) as the only true brachiators and classify the great apes as modified brachiators. All other brachiation behaviours that do not meet either of these classifications are referred to as forearm suspensory postures and locomotion.

(Continuing from the sentence "This form of locomotion is the primary means of locomotion for the small gibbons and siamangs of southeast Asia") :

Gibbons use brachiation as their main form of locomotion, as they use this type for gait in 80% of their locomotor activities. This can be compared to the African Apes who only use brachiation for less than 5% of their locomotor activities.

(See Also: Arboreal locomotion)

Types of Brachiation
Continuous Contact

This form of brachiation occurs when the primate is moving at slower speeds and is characterized by the animal maintaining constant contact with a handhold, such as a tree branch. This gait type utilizes the passive exchange between two types of energy, gravitational potential and translational kinetic, to propel the animal forward at a low mechanical cost. This mode of brachiation has been compared to the movement patterns of bipedal walking in humans.

Ricochetal

This type of brachiation is used by primates to move at faster speeds and is characterized by a flight phase between each contact with a handhold. Ricochetal brachiation uses an exchange of translational and rotational kinetic energy to move forward, and is compared to a "whip-like" motion. Due to its aerial phase, ricochetal brachiation is similar to bipedal running in humans.

Models of Brachiation
Pendulum Movement

Continuous contact brachiation has often been compared to the movement of a simple pendulum. This is due to the out-of-phase fluctuation of energy that occurs while the moving primate is swinging between each tree appendage as the energy transfers from potential to kinetic, and vice versa. The use of gravitational acceleration to effect movement can be found in both the brachiating primate and the moving ball in a pendulum model. A brachiator can make use of this momentum in several different ways: during the downswing the primate can maximize its change in kinetic energy, during the upswing it can minimize loss of kinetic energy or (also during the upswing) it can avoid moving laterally during its swing. Brachiating primates have adapted these three strategies for maximizing forward movement by adjusting its posture during each swing.

The amount of energy transferred from potential to kinetic during pendulum-like movement is known as energy recovery. Maintaining a higher energy recovery during brachiation costs less energy and allows the animal to move to its destination quickly, however, this type of movement is also harder to control. Therefore, since the risk of missing a handhold can result in injury or death, the benefit of moving with a lower energy recovery and more control likely outweighs the cost of extra energy expenditure.

Evolution of Brachiation
Specialized locomotor behaviours, such as brachiating, are thought to have evolved from arboreal quadrupedalism. This behaviour is the ancestral and most common locomotor mechanism among primates. This would explain why living apes and humans share many unusual morphological aspects of the upper limb and thorax. The transition to brachiation is regarded as a major shift during primate evolution and is thought to be a possible precursor to the adaptation of bipedal walking in early hominids. Specialized suspensory behaviour was shown to have evolved independently between hominid groups.

There are several hypothesizes for how early brachiating primates may have transitioned into bipedalism. The most generally accepted of these is the vertical climbing hypothesis, which states that vertical climbing is the biomechanical link between brachiation and bipedalism. Many climbing adaptations have been found in early hominins and some of these adaptations can still be seen in present day humans. The distinctive body posture, limb proportions and trunk design identified in living apes are better explained by the previous adaptation of climbing behaviours.

Peer Review by Caroline McDonald
The article is missing a clear, working definition of Brachiation. It may be beneficial to state this first then go into history and development. The sub-sections are very good but it may be useful to add in a section about why it is beneficial to a species. This section may link into its evolution. There are few examples of species that use this locomotion and that may be a good way to demonstrate its working definition.

Linking Brachiation back to Tinbergen's four questions may help develop the section on "Evolution of Brachiation". Moreover, maybe a section on the modalities of this behaviour and the underlying mechanisms associated with it. Locomotion has biological component of course, so developing on this is an important part of the behaviour as a whole. The current sub-sections could have more content. Perhaps expanded on topics of kinetic energy and other species that use it may be useful.

Aside from the content of the article, there are some grammar and sentence structure errors. The lead section is slightly confusing and needs a clearer transition and more elaboration. Some pictures would also be beneficial.

Overall, the article is quite good and has a concrete body.