The Pony Fish's Glow and Other Cues to Plan and Purpose in Nature - Assignment Example

Paper Reaction thoughts on Chapter 3 In the first three chapters, the introduced several important concepts concerning evolutions, natural selection vs artificial design, adaptations, sexual selection and other selection forces, mendelian genetics and the decision for the good of the species or individual interest. The author used different examples to aide his arguments. One of the things that struck me most is that the process and the outcome of natural selection could be similar to the artificial selection practiced in farming and poultry raising. Evolution or natural selection put an emphasis on the interaction between the physical environment and the species. As we have practiced farming for thousands of years, the domesticated crops are very different from the wild crops we can find in the wild. We have purposely selected the crops with higher starch content and bigger grain sizes and most importantly, we provided the crops a very different growing environment (habitat) and I think this contributes to the shaping of the crops too. I found it very interesting that several arguments presented can be linked to our behavior, i.e. the establishment and the importance of social status and the question of individual interest. In the book, the author explained that the establishment of social status, especially among males, is essential in sexual selection. The stronger male obtains a larger or better territory through fighting with other males, and therefore can reproduce successfully. In modern society, everybody fight for more resources, not by physically engaged to each other, but we compete in schools for higher grades or trying to perform better in jobs. Social status in modern society is majorly gained through having higher income and better jobs. All these can result on better career prospects or higher salary, which can be interpreted as being more resourceful. A more resourceful person can raise their children better (providing better food and education) can make their children more successful and thus their genes are more likely to pass on to the next generation. In modern society, individual rights and responsibility are the essential elements that keep a society in order, but there is a constant struggle between what is the best for ourselves and what is the best for the society. We can maximize our interest if we are allowed to do we can, if this may do harm to the others. Therefore rules are set up to protect everyone’s interest and at the same time, trying maximize everyone’s chances to success. However, I think the line drawn between the good of the species and to maximize individual interest also depends on the resources available in the society. In bee colony, the worker bees work collectively to gather food and keep the colony functioning, for the sole purpose to allow their genes, in which half of those share with the queen, can be passed on to the next generation. Some other species have dominant males, which can mate with one or more females, even though the total number of males and females are similar in a population. The more successful males ensure that better genotypes can be passed on to the next generation. This will increase the chance for the next generation to survive. This happens when the selection force is strong and the environment does not provide enough resources to sustained weaker individuals. However, this is not true for the modern society, where we have enough food and good hygiene environment to allow the ones with ‘weaker genotypes’ to develop themselves. After reading these three chapters, I understand ourselves as human better and also have a more in-depth understanding about our society. Our society and behavior seem to be shaped by the same selection forces as in other species in animal kingdom, even though we are more sophisticated culturally and technologically. Paper 2: Reaction thoughts on Chapter 4-6 These three chapters started with the author trying to distinguish our bodies as ‘thinking’ machines’ and our ‘souls’, which can be represented by our thoughts and mind. Then he proceeded to explain why different between sexes exist or why sexual reproduction is important in some species. Lastly, he described in details how sexual reproduction is for humans. Nowadays, with the advancement in many aspects of biological sciences, we sometimes tend to regard our bodies as delicate and complex machines. We often hear in the news that scientists discover a new enzyme or a new mechanism that allows us to understand how our body works or to cure cancer. It is suggested if we inject a certain kind of drug or correct an ‘error’ in our genetic makeup, then a life-threatening disease can be cured or hereditary disease can prevented. The most important achievement in bioengineering in recent decades is the cloning of mammals. It is essentially the asexual reproduction in mammals, allowing the direct replication of an organism without the use of gametes and the presence of a mate. Scientists have predicted that in the future, tissue organs can be cultured from our own cells for organ transplant, reducing the risk of immune response against tissue organs from other donors. Human body is just like a machine that can be assembled. However, research in neuroscience suggested that nerve endings make connections to each other when we learn new things. Therefore, although identical twins may have the identical genetic materials and thus are identical in protein levels, they may still be different in their connections between neurons if they are raised in different environments. The learning and the formation of memories are part of the ‘souls’. I think people should not be defined only by physical appearances, which largely contributed by the genetic factors, but also the ‘souls’ or mentality, which is the non-physical or non-chemical property of our species. Sexual reproduction is a part of adaptations to the changing environment. Sexual reproduction produces offspring which inherit the genes from their parents, but the genetic ‘blueprints’ are different from their parents. This variation is beneficial to the species because a species is subjected to the ever-changing environment, for example a viral disease may wipe out the entire population if not one individual can develop immunity against this viral strain. However, sexual reproduction poses problems such as the availability of mates, the continuous sexual selection. For peacock to successfully win a mate, they develop the heavy, decorated tail. Not only it is energy-consuming to produce extra feathers, but the extra weight of the tail will reduce the chance of survival of the peacock if it needs to escape from its predator. For females, the presence of eggs or fetus inside their body also causes retardation in their movement. In my opinion, the cost of having sexual reproduction is very high because organisms have to invest heavily on phenotypic and behavior changes to the point that these changes may threaten the survival of the organisms themselves. It would be interesting to speculate what will happen if organisms develop in a more stable environment, such as better hygiene and resourceful environment in modern society, which has a lower selection pressure or organisms invest more of their energy into mechanisms that promote longevity in which the pressure to reproduce is reduced. The need for sexual reproduction in humans has affected different social customs in different cultures. The most prominent examples will be monogamy and polygamy practiced by different cultures. Personally, I think monogamy is only possible when resources are scare in which the either sex cannot support one more mates or offspring by produced by other mates. It is common in different cultures that the male practicing polygamy is richer and have a higher social status. One of the interesting things in modern societies is that although by law people have to practice monogamy, with the increasing divorce rates, I think people nowadays tend to practice polygamy in reality. Paper 3: Reaction thoughts on Chapter 7-9 . In chapter 7-9, the illness brought by senescence and affluent lifestyle and symptoms as body’s adaptation to illness were discussed. The author suggested that biochemical mechanisms of human body are more adapted to ‘gather-hunter’ lifestyle, implying the evolution of human body is not in line with the changes of diet and lifestyle. In contrast, micro-organisms were used as examples to demonstrate rapid evolutionary changes due to shorter lifespan and increasingly challenging environment caused by the application of antibiotics. Lastly, he discussed the moral and philosophical implications of evolution. It is true that the life expectancy of modern humans has increased significantly and thereby bringing a variety of illness scarcely encountered by humans in ancient societies. These diseases include cancer, hypertension, metabolic syndrome etc. Obesity is known to be a common risk factor to these diseases and so one can speculate that increased food intake resulted from agricultural revolution and increased productivity. I think the dilemma nowadays is now to encourage people to eat less when food is plentiful or to increase physical activity when a lot of things can be performed by machines. Urban life encourages sedentary lifestyle, not only because different transportation facilities are available to reduce physical activity. The quick pace of urban lifestyle leads to nervousness in a lot of people and thus, people spend majority of leisure time on activities with strong visual or auditory stimulation but not on physical exercises. One way to improve situation is to reduce the working hours of people and thus the mental stress of the people. This may increase their willingness towards having physical exercises. It has been known for a long time that the mutations and subsequent generation of antibiotics-resistant strains of bacteria are fine examples of evolution. The author suggested we should not transmission of the disease in first place, instead of using antibiotics with stronger potency. If the micro-organisms did not proliferate or have reduced number of available reservoir in a population, the chances that they develop into virulent strains will be minimized. Prevention of transmission should always be the first line of defense in combating viral or bacterial diseases. Another thing that strikes me is that if all the antibiotics have failed, our standard of medical treatment may fall back to the conditions decades before. For example, organ transplant will be very difficult to perform since effective antibiotics are needed in recipients. Patients with cancer undergoing with chemotherapy or patients with suppressed immune system will be put into greater risk because they are more prone to microbial infections. The use of antibiotics is very common in modern medical practice and care should be given in transcribing and taking of these valuable drugs. Many years ago, there is a documentary showing how a group of primates killed an animal for meat. It aroused a great controversy, although people usually don’t complain when documentary showing a lion killing an antelope. I think people got sensitive because primates and humans are more alike. This implied a moral judgment in the act of killing, as ‘human’ should not kill, but the only way for a lion to get its food is through hunting, so the lions are not morally ‘wrong’. Another example is a film showing the life of penguins in Antarctica. The behavior of the penguins exhibits a high degree of parental care, and some people have used this to support different arguments from creationism to the moral importance of family value. Personally, I think the parental care exhibited by the penguins is one important way to ensure their genes to pass on to the next generation, since they produce just one chick at a time. For some bird species, ‘adultery’ can often be found since in this way, a bird (usually female) can ensure its offspring have the good genotype as well as the parental care. In the matter of survival, the argument of morality may not be valid. Read More