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Article 6 Summary Continued

Submitted by brdougherty on Fri, 12/08/2017 - 11:25

The results of this experiment showed that the lactate concentration in the blood while basking did not change when compared to previous lab experiments. In foraging Iguanas it was found that the average blood lactate concentrations was 1.55 + 0.55 umol/m. In the forced running experiment the lactate levels were found to be similar to those found in previous lab experiments and they continued to increase even after they stopped running. When the iguanas were forced to dive their blood lactate levels increased and continued to increase even while they were cruise swimming after the dive. However, it was observed when the iguanas were not disturbed to draw blood when diving and the allowed to free swim there lactate blood concentration eventually started to decrease during swimming. Through these results Gleeson concluded that the marine iguanas were very similar to other species of lizards and usually only transition to anaerobic energy production during burst activities that may be considered stressful. 

Elevator Speech: Perfect Paragraph

Submitted by brdougherty on Fri, 12/08/2017 - 11:05

In this experiment I examined if planarians had a preferential behavior for a particular sweetener. The 3 sweeteners observed were sucrose, brown sugar, and saccharin. The way this was tested was by putting the 3 different types of sweeteners in a petri dish and allowing the planarians to move freely between the sweeteners. The results show that sucrose was the most preferred sweetener followed by saccharin, and then brown sugar. The results were rather interesting because sucrose and brown sugar have the same chemical structure besides the fact that brown sugar has molasses. At the same time saccharin offers no nutritional value yet it was more preferred than the brown sugar. This observation made the group hypothesis that molasses may have properties that deter planarians. This hypothesis should be tested farther to see if it is the reason why planarians least preferred brown sugar. 

Article 6 Summary Continued

Submitted by brdougherty on Fri, 12/08/2017 - 10:55

The daily activities examined in this experiment were basking, foraging running, swimming, and diving. In order to examine basking, blood samples were taken from marine iguanas that remained unmoving for at least 30 minutes. To ensure that the capturing process did not affect the lactate concentration samples were taken in under 45 seconds of capture. To test foraging iguanas they were captured between 1-5 minutes after returning to the shore and a blood samples were taken.  Running was tested on previously basking iguanas by forcing them to run from danger for 2 minutes and then a blood sample was taken. For the diving field experiment iguanas were forced to dive for 6 minutes and then allowed to swim freely. Lastly, Gleeson examined if swimming following a forced dive removed lactate from the blood of iguanas. This was tested by forcing iguanas to dive for 5-6 minutes and then allowing them to swim freely for 30-60 minutes all while testing their lactate level in their blood through a device previously implanted in the iguanas. 

Elevator Speech

Submitted by brdougherty on Thu, 12/07/2017 - 22:45

Past research has found that Planarians have similar addiction behaviors to humans. This led me to wonder if they had preferences for different substances. Dar and I explored if planarians had a preference for a particle sweetener. The 3 sweeteners we choose to observe were sucrose, brown sugar, and saccharin. The results show that sucrose was the most preferred sweetener followed by saccharin, and then brown sugar. The results were rather interesting because sucrose and brown sugar have the same chemical structure besides the fact that brown sugar has molasses. At the same time saccharin offers no nutritional value yet it was more preferred than the brown sugar, which made the group, hypothesis that molasses may have properties that deter planarians. 

Animal Movement Summary 6

Submitted by brdougherty on Thu, 12/07/2017 - 16:16

            In the article, Lactic Acid Production During Field Activity In the Galapagos Marine Iguana, Amblyrhynchus Cristatus, Gleeson, examines the anaerobic energy production in marine iguanas in their day-to-day activities. In order to examine if anaerobic energy production was present blood samples were extracted from the iguanas to test for lactate concentration. Past research has found that marine iguanas had large amounts of lactate present during many of their foraging activities especially diving. While past research illustrates these results Gleeson speculates that this build-up of lactate occurred do to these daily activities being forced. Gleeson, in this study will examine the lactate production during “natural field activities,” in order to reveal the true amount of anaerobic energy production present in marine iguanas in their daily activities. 

Perfect Paragraph: Animal Movement Article Summary

Submitted by brdougherty on Fri, 12/01/2017 - 11:26

The results in this study were conclusive showing that the amount of fast twitch muscle and longer muscle fiber in chimps contribute to them being stronger than humans. While these results were conclusive unanswered questions remain. In future experimentation it needs to be examined why chimps displayed a 1.35 times higher dynamic force in computer simulations while previous experiments show a 1.5 times higher dynamic force.  While in the paper they speculate that this may occur due to “differing excitations acting across joints with variable leverages,” I believe this needs to be experimented more in order to prove this hypothesis.  I also believe that more than 3 chimpanzees should have been used in this experiment to observe if there was a significant difference between the chimp population. While I do believe these adjustments should be made I believe that this study was a very clear laid out study that displayed why chimpanzees are stronger than humans.

Animal Movement article 5 continued

Submitted by brdougherty on Fri, 12/01/2017 - 01:12

While these results were conclusive that the amount of fast twitch muscle and longer muscle fiber contribute to chimps being stronger than humans it leaves some unanswered questions. One thing I believe needs to be examined more is that while chimps displayed a 1.35 times higher dynamic force in computer simulations previous experiments show a 1.5 times higher dynamic force.  While they speculate that this may occur due to “differing excitations acting across joints with variable leverages,” I as a reader believe this needs to be experimented more in order to prove this hypothesis.  I also believe that more than 3 chimpanzees should have been used in this experiment to observe if there was a significant difference between the chimp population. While I do believe these adjustments should be made I believe that this study was a very clear laid out study that displayed why chimpanzees are stronger than humans. 

Animal Movement article 5 continued

Submitted by brdougherty on Thu, 11/30/2017 - 20:12

The results illustrated that human and chimpanzee muscles Po and Vo are not significantly different which means commonalities are expected in properties that affect single fiber performance. The results also illustrated that chimps have a higher percentage of fast twitch muscle and longer muscle fibers (both absolute and relative). Longer muscle fibers may increase the dynamic force, work, and power capabilities of a muscle tendon unit.  The results also show that having a higher percentage of fast twitch muscles when compared to humans is common among primates.  This led O’Neill to hypothesis that the higher percentage of slow twitch muscle in human skeletal muscle occurred within the human lineage, as they became less dependent on fast twitch muscle. Lastly, through the computer simulations performed it was found that chimpanzee muscles have a 1.35 times higher maximum dynamic force. Ultimately, O’Neill concluded that the results suggested, “that the larger fraction of MHC II fiber (fast twitch muscle) and the longer muscle fiber lengths characteristic of chimpanzee skeletal muscle will increase their dynamic force and power producing capabilities overall. 

Animal Movement article 5 continued

Submitted by brdougherty on Thu, 11/30/2017 - 19:05

While these differences were previously hypothesized no experiment has been preformed that have directly measured these skeletal muscle parameters in chimpanzees. Since these parameters have never been measured O’Neill decided to directly measure single-fiber contractile properties and MHC isoform distributions of chimpanzee skeletal muscle to test these previously stated hypothesis. Once these measurements were taken the data was compared to humans and other mammals using computer simulations. 

Animal movement article 5 summary

Submitted by brdougherty on Thu, 11/30/2017 - 16:36

            In the article, Chimpanzee Super Strength and Human Skeletal Muscle Evolution, O’Neill and his colleagues examine the differences between human and chimpanzee muscle in order to explain why chimpanzees are stronger when compared to humans.  After critically reviewing previous experiments O’Neill found that muscle performance of chimpanzees on average outperform their human counterparts consistently by 1.5 times. In order to explain this strength differential it has been previously hypothesized that chimpanzees have a higher isometric force-producing capabilities, faster maximum shortening velocities, and/or a different distribution of MHC isoforms when compared to humans. 

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