Animals in nature must be able to bolt away from their predators and be able to stay away from their predators. Therefore, speed is just as important as stamina in any running race. Animals hunt in different ways, as some are quick to pounce on their prey, while others enjoy a chase. Recently, researchers compared muscle tissue in cheetahs and tigers in an effort to understand the physiological differences in animals with different hunting techniques. The cheetah requires speed, agility, and power whereas the tiger needs to be able to travel long distances.
Scientists examined muscle samples from one cheetah and two tigers looking specifically at the composition of the myosin heavy chains. Previous work in the field has shown certain muscle fibers having particular levels of muscle activity. Altogether the different forms of myosin heavy chains have been classified as being fast or slow. As predicted researchers observed a greater percentage of slow fibers present in the tigers than the cheetahs. In addition, cheetahs had a greater percentage of fast twitch muscles than the tigers. Researchers believe this difference may have developed over time to suit the hunting needs of either animal.
The differences in these muscle fibers have huge effects on the mobility of these animals. While tigers are able to reach speeds of 45lm/h, cheetahs are able to reach speeds of 120km/h. The physiological makeup of each animal suits its preferred hunting style. There are, however, a few limitations to this study. Only 3 animals were used for analysis and this small sample size may not reflect a larger trend. Similarly, the study was based on tissue samples from animals in captivity, and the altered living conditions may have altered musculoskeletal structure.
-Himanshu Shah (3)
I think it makes sense that hunting styles and muscle types would influence each other - as hunting styles develop, it follows that the animals with muscle better-suited to a particular strategy would be better off than those with different/less of that sort of muscle. Were any other differences discussed apart from muscle types?
ReplyDeletePosted by Dana Mirsky
Depending on how the tissues evolve it could be quite possible that living conditions can effect how the muscle tissues mature. It seems to me like this looks like natural selection and it is very interesting. If the tissue type is really hardwired, than I would expect not much of a difference between the cats in captivity and the ones in the wild. If they were more developmental and somewhat hardwired, the cats in captivity may have slightly different muscle fibers. Who knows...maybe if a cheetah was reared in a very small environment until adulthood with little running space their muscle composition with be very different. It would be a interesting experiment to do.
ReplyDelete-Katie Cyr
That is pretty interesting. I know even over a period of a lifetime a long distance runner can convert some of their fast twitch muscle into slow twitch. This is proof of this evolution and how it can separate from one another even within the same family. Did it mention any other changes besides muscle like neurological or skeletal?
ReplyDeletePatrick Salome
It definitely makes sense their an organism's lifestyle would correspond to the type of internal organs needed for that lifestyle. I know that the tuna have these "red" muscles, which allows them to swim long distances while the barracudas have "white" muscles, which allows them to sprint through water quickly. These fishes not only have internal adaptations but external ones, such as the form of their bodies. What other features would help contribute to these two cats' different lifestyles? Also, would a wild cat have a different buildup than a captive one? I would imagine wild samples would be difficult to calculate due to poor conditions of little habitats and prey, but wouldn't it be interesting to compare the different external pressures on the wild and captive? I think it would be interesting to see the anatomy of generation of cats that only live in the wild.
ReplyDeleteLeona Chan
The results the researchers got don't seem surprising, given the different hunting strategies between the two species. Did the article mention any other physiological differences they evolved to suit their respective hunting styles? Like maybe lung capacity, or other indicators of endurance.
ReplyDelete-Jane de Verges
Did the article talk about the skeletal makeup of the two animals and how that plays a role in their hunting strategies?
ReplyDeleteCharles Carville
Interesting post! Cheetahs are the fastest running species in the world. Having said that, this research data shows the evidence and perhaps the mechanism governing how these species runs so fast. Does this research tie anything with the evolutionary process of hunting in cheetahs vs tigers? It would be interesting to see how cheetahs, tigers, lions and other similar species evolved to develop certain hunting strategies and compare it to their physiology.
ReplyDeleteLoba Alam
Thanks for reading my article and coming up with some interesting questions.
ReplyDeleteDana-The main purpose of the study was to examine whether what is currently known about different MHC isoforms correlates with and seeing if they matched the different hunting styles. Aside from muscle types, researchers also discovered some unique physiological adaptations within cheetahs. They found that cheetahs did not have a soleus muscle. In humans and other animals this powerful musle is located in back part of the lower leg. This muscle has many morphological differences across species and can be used for comparison. Additionally researchers found that cheetahs had special MHC isoforms that differed in reactivity in comparison with other species.
Katie- Your suggestion for another experiment is a good idea. Although some percentage of the fibers may be hardwired, there may be a certain percentage of fibers that develop through experience. Comparing the results of a sedentary and wild animal would provide interesting results on this idea.
Patrick-Unfortunately the article did not delve deeper. Keep in mind that changes this article looked are based on differences in percent composition of different fibers. This means that they do contain similar fibers just varying amounts that seem to affect mobility.
Leona-Some other factors affecting the lifestyles of these animals are diet, environment, and predators. I also agree with you that running an experiment like that would be interesting. Katie mentions this idea as well so see my response to her on this topic.
Jane-Although the results may not seem important, they provide scientific evidence on the differences in composition of muscle fibers in different species. The two species contain similar fibers just varying amounts that seem to affect mobility. Some physiological differences between the two animals are the lack of soleus muscle in cheetahs and different MHC isoform activity in cheetahs.
Charles-I assume you are referring to the different physiological differences. As stated earlier, Some physiological differences between the two animals are the lack of soleus muscle in cheetahs and different MHC isoform activity in cheetahs
Loba-Unfortunately, the article did not dive into evolutionary mechanisms too much. There was a small discussion the evolution of different hunting patterns and how this may have affected muscle composition.
-Himanshu