1. Darwin's natural selection is a theory of evolution in which everything is believed to change because of what nature selects to survive. This theory has limitations, though: it cannot produce a perfectly engineered trait. That evolution is constrained is quite obvious especially for big creature, even more especially with big specialized animas like the cheetah.
2. Lacking necessary genetic variation is one of the limitations of evolution. In this case, one can only operate with whatever genes are available. Darwin's selection theory is constrained because of species' histories. Here, basic body forms of species cannot be altered much. Trade-offs are limited because changing one feature for a better one can have worse results.
3. Cheetahs are the fastest animals on land. They can run up to 120 kph on short stretches. What may be done to make them run faster?
Cheetahs could run faster if they had "faster" alleles, but they would have to evolve many other features in their body. Different arrangements of leg muscles and bones would also be needed to cause cheetahs to run faster, or they would need to acquire genes to improve oxygen use. This, in turn would require metabolic mutations having to do with digestion and many other processes. It is not likely that a cheetah's evolution could accomplish a wide range of such changes; at least if it is to remain as a kind of cat.
4. Since we could breed animals to produce better strains, as we have done with dogs, we could also cut genes and past it to others in a process called genetic recombination.
A genetic experiment, however, is likely to have unpredictable effects, too. Thus, even if the cutting and pasting or breeding worked to produce a faster cheetah, that cheetah might not be the best overall: running faster has its disadvantages (overheating, for example). Producing a better cheetah will be a process so long and unpredictable, that even with the best forms of assistance man will not be patient or wise enough to handle all the mistakes that will have to be made.
In short, natural selection by the wild is probably the best way to produce a good cheetah--not perfect, but better than we can, at least for living in the wild, where cheetahs are at their most awesome beauty.
5. Each species evolved to be almost at its best that if we will change them into something we think is better, we will likely end up with something worse, or only limitedly better. Therefore, we should just be contented on how we were made, because this body of ours was made with our best on the creator's mind, and evolved accordingly.
But the really interesting thing about all this is an implication: If evolution cannot engineer a perfect trait, then at least some of the characteristics we have are not perfect; some even have no use. For instance, what use are dimples, or earlobes connected fully to the face, ar the ability to roll the tongue? Why are these "useless" traits there?
The answer strikes at the heart of strict Darwinism: survival of the fittest is not everything. One can also have survival of the lucky (genetic drift ad bottleneck phenomena), survival of the neutral (traits that are neither advantageous or disadvantageous), and in many cases, survival of the bad (e.g., sickle cell anemia) because the bad trait allows organisms to escape an even worse fate.
References:
http://evolution.berkeley.edu/evolibrary/article/0_0/misconcep_03
http://en.wikipedia.org/wiki/Cheetahs
(Gwen Alexis Gapas is a student at the University of Asia and the Pacific. lexi.gapay@yahoo.com)
Wednesday, March 19, 2008
Sunday, March 16, 2008
Palsis, J. (2008). Limitations in Knowledge
1. Man by nature is curious. It is natural for men to try to know almost everything. Man has used what he knows to make his life comfortable. However, man's actions have put nature in an uncomfortable situation, which is the isolation of man from nature. The way man views phenomena has changed throughout time because of the different changes in the way man interprets causes and effects. The way man views nature now is partly the reason for this uncomfortable situation.
2. Objectivization and fragmentation of knowledge are putting man in this uncomfortable situation. Objectivization means that nature is seen as having nothing to do with humans. Objectivization removes the responsibility man has for nature; when something is objectivized it will mean nothing to men. Fragmentation is the closure of the different fields of knowledge to each other. A biologist can think that biology has all the answers to every question. However, an economist can also think the same and ignore the ideas of the biologist, therefore creating a gap between the two. Objectivization and fragmentation result in the isolation of man from nature, as well as the isolation of men from each other.
3. According to Miller (2003), up to around the time of Bacon, events in the natural world had a cosmic significance that tended to unite all these events, giving them a kind of unified meaning. In the time of Egypt, the unifying meaning was religious: men took changes in nature as omens from the gods.
Around the time of Aristotle until the Middle Ages, the unifying element was the metaphysical act of being. The interpretation of the act of being ranged from the Platonic concept of the visible world's participation as reflections of ideal concepts that had real existence in an ideal world, to the Thomistic idea of the participation of all beings in the act of being that had its perfection in the Ultimate Cause, God. In contrast to the ancient world, the Aristotelian world allowed for natural causes explaining natural effects, but looked further into an ultimate cause such as God.
Knowledge in the ancient and in the Aristotelian worlds had deep ethical consequences. Not necessarily with the Baconian world. With Bacon came the idea that the visible natural world was sufficient for knowing cause and effect; metaphysical ultimate causes and ethics may be valid ideas on the personal level, but they serve little or no purpose in understanding nature. Nature should be known objectively. In the Baconian view, we should close all our connections and relations to nature to know it without bias.
Miller (2003) discussed this evolution of "how we know" using the the famous case of an "epidemic" of deformed frogs that occurred in Minnesota in 1995. When the outbreak started, environmentalists jumped to the conclusion that commercial pesticides caused the deformations. Environmentalists may have said this partly because they wanted to influence the government's decision about pollution. Other researchers came and proposed other causes for the deformities, such as radiation from the sun and parasites called trematodes. Other researchers blamed the trematode outbreak as resulting from eutrophication.
In essence, everyone was trying to blame everybody except themselves. Miller blames this on objectivization and fragmentation. Aside from the isolation of man from nature, men have also isolated themselves from each other, ignoring the ideas of each other.
4. Objectivization and fragmentation have, in a sense, demonstrated their use as powerful tools to know and control nature. After all, a biologist concentrating on a biological problem long enough can discover an indefinite series of causal chains extending from the atomic to the ecological level. The string of scientific achievements in all modern sciences including biology is proof of the power of objectivization and fragmentation.
Inherent to objectivization and fragmentation, however, is the idea of bounded knowledge, which means that knowledge is limited. The first boundary put up by Bacon was that between the physical and the metaphysical sciences; more boundaries were set up between fields within the physical sciences themselves. But even these boundaries ignore another boundary set up from the time of the ancients and respected by many even today: the boundary between what man can know and what are beyond his ability to discover: the supernatural truths.
Man certainly must not stop from exploring because there are truths he can not discover by the methods of the physical or even the metaphysical sciences. But, to remain confined within the boundaries of a field of knowledge presents the temptation to see the world through filtered glasses and to deny the contribution of other fields.
Going further, the supernatural truths allow men to transcend the boundaries of the measurably and observable, allowing them not only to see a bigger picture of the world, but also to see the ethical implications of their role. The ethical implication is not only a bigger picture; it is also a lasting picture, as the supernatural is essentially beyond time.
5. Man can be good in having knowledge. However, man is not able to acquire perfect knowledge. Instead, man can choose a specific field of knowledge and specialize in it. But we should always remember to integrate what we know to other fields of knowledge. As for the supernatural realities, we have to recognize their importance. Since such realities are beyond the immediate verification of measurement and are highly conditioned by personal experiences and culture (as well as objective realities), the first step in understanding them is through dialogue.
Dialogue, in the end, is an essential step in avoiding the narrow-minded views, while enabling us to enjoy the usefulness of treating nature objectively and specializing in our favored fields of knowledge.
References:
Miller, G.L. (2003). "Dimensions of deformity". In Keeping Things Whole: Readings in Environmental Science. The Great Books Foundation, Chicago, IL, USA, pp. 275-288.
(Julius Palsis is a student at the University of Asia and the Pacific. julius_palsis@yahoo.com)
2. Objectivization and fragmentation of knowledge are putting man in this uncomfortable situation. Objectivization means that nature is seen as having nothing to do with humans. Objectivization removes the responsibility man has for nature; when something is objectivized it will mean nothing to men. Fragmentation is the closure of the different fields of knowledge to each other. A biologist can think that biology has all the answers to every question. However, an economist can also think the same and ignore the ideas of the biologist, therefore creating a gap between the two. Objectivization and fragmentation result in the isolation of man from nature, as well as the isolation of men from each other.
3. According to Miller (2003), up to around the time of Bacon, events in the natural world had a cosmic significance that tended to unite all these events, giving them a kind of unified meaning. In the time of Egypt, the unifying meaning was religious: men took changes in nature as omens from the gods.
Around the time of Aristotle until the Middle Ages, the unifying element was the metaphysical act of being. The interpretation of the act of being ranged from the Platonic concept of the visible world's participation as reflections of ideal concepts that had real existence in an ideal world, to the Thomistic idea of the participation of all beings in the act of being that had its perfection in the Ultimate Cause, God. In contrast to the ancient world, the Aristotelian world allowed for natural causes explaining natural effects, but looked further into an ultimate cause such as God.
Knowledge in the ancient and in the Aristotelian worlds had deep ethical consequences. Not necessarily with the Baconian world. With Bacon came the idea that the visible natural world was sufficient for knowing cause and effect; metaphysical ultimate causes and ethics may be valid ideas on the personal level, but they serve little or no purpose in understanding nature. Nature should be known objectively. In the Baconian view, we should close all our connections and relations to nature to know it without bias.
Miller (2003) discussed this evolution of "how we know" using the the famous case of an "epidemic" of deformed frogs that occurred in Minnesota in 1995. When the outbreak started, environmentalists jumped to the conclusion that commercial pesticides caused the deformations. Environmentalists may have said this partly because they wanted to influence the government's decision about pollution. Other researchers came and proposed other causes for the deformities, such as radiation from the sun and parasites called trematodes. Other researchers blamed the trematode outbreak as resulting from eutrophication.
In essence, everyone was trying to blame everybody except themselves. Miller blames this on objectivization and fragmentation. Aside from the isolation of man from nature, men have also isolated themselves from each other, ignoring the ideas of each other.
4. Objectivization and fragmentation have, in a sense, demonstrated their use as powerful tools to know and control nature. After all, a biologist concentrating on a biological problem long enough can discover an indefinite series of causal chains extending from the atomic to the ecological level. The string of scientific achievements in all modern sciences including biology is proof of the power of objectivization and fragmentation.
Inherent to objectivization and fragmentation, however, is the idea of bounded knowledge, which means that knowledge is limited. The first boundary put up by Bacon was that between the physical and the metaphysical sciences; more boundaries were set up between fields within the physical sciences themselves. But even these boundaries ignore another boundary set up from the time of the ancients and respected by many even today: the boundary between what man can know and what are beyond his ability to discover: the supernatural truths.
Man certainly must not stop from exploring because there are truths he can not discover by the methods of the physical or even the metaphysical sciences. But, to remain confined within the boundaries of a field of knowledge presents the temptation to see the world through filtered glasses and to deny the contribution of other fields.
Going further, the supernatural truths allow men to transcend the boundaries of the measurably and observable, allowing them not only to see a bigger picture of the world, but also to see the ethical implications of their role. The ethical implication is not only a bigger picture; it is also a lasting picture, as the supernatural is essentially beyond time.
5. Man can be good in having knowledge. However, man is not able to acquire perfect knowledge. Instead, man can choose a specific field of knowledge and specialize in it. But we should always remember to integrate what we know to other fields of knowledge. As for the supernatural realities, we have to recognize their importance. Since such realities are beyond the immediate verification of measurement and are highly conditioned by personal experiences and culture (as well as objective realities), the first step in understanding them is through dialogue.
Dialogue, in the end, is an essential step in avoiding the narrow-minded views, while enabling us to enjoy the usefulness of treating nature objectively and specializing in our favored fields of knowledge.
References:
Miller, G.L. (2003). "Dimensions of deformity". In Keeping Things Whole: Readings in Environmental Science. The Great Books Foundation, Chicago, IL, USA, pp. 275-288.
(Julius Palsis is a student at the University of Asia and the Pacific. julius_palsis@yahoo.com)
Wednesday, March 12, 2008
Ong, K. (2008). Mice for Men
I
The mouse has been the mainstay of laboratory research on human illness and will most likely remain an important player in future studies. About 25 million mice are used in laboratories around the world to test new drugs and new notions about the biochemical machinery of living organisms.
There are many animals that can be used in animal testing; but why does it need to be mice? Mice are used because it is said that mice and men have a common ancestor.
II
International teams of researchers recently published a nearly complete sequence of the genetic instructions of "Black 6", the most common breed of laboratory mouse, and matched its traits with the recently decoded human genome (Russell 2002). Surprisingly, comparison of the sequences shows that mice and humans came from a common ancestor known as Eomaia scansoria, the earliest known representative of the Eutheria lineage that gave rise to placental mammals (Russell 2002). This common origin implies common genes, and this similarity allows mice to be a reliable animal for testing products destined for human use.
III
Mice and humans both have about 30,000 genes, 85% of which are the same. It is also said that 90% of genes associated with disease are identical in humans and mice. The assumption behind animal testing is that because of these genes, mice are a good model for physiological responses in the human that result from exposure to drugs, and even to new kinds of food and food supplements.
One example of the use of mice in developing new products is green tea extract. Green tea extract does make mice stronger swimmers, Japanese researchers report (De Noon 2005). Ten weeks of green tea supplements plus strenuous exercise made mice swim longer and stronger than mice that swam their laps without supplements. "We have shown that green tea extracts are beneficial for improving endurance capacity, and that this effect is accompanied by a stimulation of [fat] metabolism," Takatoshi Murase writes (De Noon 2005). Mice results suggest that green tea extract may be a useful tool for improving endurance in humans.
However, Murase calculates that the amount of green tea eaten by the mice would work out to about 4 cups of green tea a day for a 165-pound human athlete, about a little less than a liter of tea a day (De Noon 2005).
IV
However, simply having the same, or rather similar, genes is not enough to justify using mice as human substitutes because the genes are not identical and are probably not regulated in the same way; nor do they interact with other genes in the same way in different species. Thus, we need to use other animals that can fill in for the genes of humans that do not behave in the same way in the rats. That is why dogs, monkeys, and other animals are used. Often the choice of animal depends on the physiological response targeted, such as the choice of rabbits for testing eye medications or the choice of monkeys for testing human vaccines. By using several animal substitutes, a more complete drug effect picture is obtained, allowing more accurace predictions about the consequences of making the substances available for human use.
V
Mice will continue to be among the best model organismfor human beings. Moreover, using mice in animal testing results in a fast pace of drug research, since mice are also cheaper, easier to find and maintain, and less ethically constrained than are human subjects.
Since mice are already the ones used in testing many new products, there is much less need for humans to risk their health in trying even simple but new products first.
References:
1. De Noon, D.J. 2005. Green tea performance secret. http://www.cbsnews.com/stories/2005/01/28/health/webmd/main670072.shtml. Accessed February 2008.
2. Russell, S. 2002. Of mice and men. San Francisco Chronicle, 5 Dec 2002. Accessed online from http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2002/12/05/MN153329.DTL&type=science.
(Kathleen Ong is a student at the University of Asia and the Pacific. kathong20@yahoo.com)
The mouse has been the mainstay of laboratory research on human illness and will most likely remain an important player in future studies. About 25 million mice are used in laboratories around the world to test new drugs and new notions about the biochemical machinery of living organisms.
There are many animals that can be used in animal testing; but why does it need to be mice? Mice are used because it is said that mice and men have a common ancestor.
II
International teams of researchers recently published a nearly complete sequence of the genetic instructions of "Black 6", the most common breed of laboratory mouse, and matched its traits with the recently decoded human genome (Russell 2002). Surprisingly, comparison of the sequences shows that mice and humans came from a common ancestor known as Eomaia scansoria, the earliest known representative of the Eutheria lineage that gave rise to placental mammals (Russell 2002). This common origin implies common genes, and this similarity allows mice to be a reliable animal for testing products destined for human use.
III
Mice and humans both have about 30,000 genes, 85% of which are the same. It is also said that 90% of genes associated with disease are identical in humans and mice. The assumption behind animal testing is that because of these genes, mice are a good model for physiological responses in the human that result from exposure to drugs, and even to new kinds of food and food supplements.
One example of the use of mice in developing new products is green tea extract. Green tea extract does make mice stronger swimmers, Japanese researchers report (De Noon 2005). Ten weeks of green tea supplements plus strenuous exercise made mice swim longer and stronger than mice that swam their laps without supplements. "We have shown that green tea extracts are beneficial for improving endurance capacity, and that this effect is accompanied by a stimulation of [fat] metabolism," Takatoshi Murase writes (De Noon 2005). Mice results suggest that green tea extract may be a useful tool for improving endurance in humans.
However, Murase calculates that the amount of green tea eaten by the mice would work out to about 4 cups of green tea a day for a 165-pound human athlete, about a little less than a liter of tea a day (De Noon 2005).
IV
However, simply having the same, or rather similar, genes is not enough to justify using mice as human substitutes because the genes are not identical and are probably not regulated in the same way; nor do they interact with other genes in the same way in different species. Thus, we need to use other animals that can fill in for the genes of humans that do not behave in the same way in the rats. That is why dogs, monkeys, and other animals are used. Often the choice of animal depends on the physiological response targeted, such as the choice of rabbits for testing eye medications or the choice of monkeys for testing human vaccines. By using several animal substitutes, a more complete drug effect picture is obtained, allowing more accurace predictions about the consequences of making the substances available for human use.
V
Mice will continue to be among the best model organismfor human beings. Moreover, using mice in animal testing results in a fast pace of drug research, since mice are also cheaper, easier to find and maintain, and less ethically constrained than are human subjects.
Since mice are already the ones used in testing many new products, there is much less need for humans to risk their health in trying even simple but new products first.
References:
1. De Noon, D.J. 2005. Green tea performance secret. http://www.cbsnews.com/stories/2005/01/28/health/webmd/main670072.shtml. Accessed February 2008.
2. Russell, S. 2002. Of mice and men. San Francisco Chronicle, 5 Dec 2002. Accessed online from http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2002/12/05/MN153329.DTL&type=science.
(Kathleen Ong is a student at the University of Asia and the Pacific. kathong20@yahoo.com)
Francia, Pamela (2008). On "Food for Thought"
I
"You are what you eat." So goes the popular saying, but little known to most people, there is actually a solid basis and grounds for that cliche. Modern humankind has been evolutionarily determined mainly with the changes of food availability over time, complemented with the occurrences of bipedalism, or the ability to walk on two legs, nd the enlargement of the human brain. Among these three parameters, however, what proved to be the most crucial for the resulting of humankind as we know it now?
II
William R. Leonard, in his article Food For Thought written in 2002 and published in Evolution: A Scientific American Reader (2006), gives proof that while food supply was a central issue in the evolution of the modern human, it was actually the occurrence of bipedalism that was the most crucial in the process of evolution for the modern human.
III
Leonard describes bipedalism as an effective feeding posture for early humans, an effective way to regulate body temperature, and a less energetically expensive way of traveling, as opposed to the energy-inefficient quadrupedalism (four-legged motion), under the consideration that the two costs of determining the energy consumption of the animal were 1) its weight, and 2) its traveling rate.
Being effective in undertaking activities, bipedalism assured humans of getting more done with less energy and in less time, particularly in acquiring more food in a more eeffective way. This is apparent in the differences in day range of the bipedal human and quadrupedal ape, wherein their separate environments determined the flow of natural selection in their species. In relation to brain activity, bipedalism guaranteed richer foods for the expanding brains of humans.
Lastly, because the upright structure of bipedalism regulated body temperature, the heat that impeded the expansion of the brain was eliminated, to be replaced by a cool blood flow that allowed the brain the growth in underwent to result in the mind as we know it now.
IV
Contrary to the position that bipedalism is the most important parameter defining the modern human race, it can be pointed out that the superiority of humans over the other biological creatures is defined by the human's capacity for thinking and more brain activity. Keeping in mind that the brain is powered by food, it is therefore implied that a larger brain size, supported by the improving nutrient intake from increaingly richer food over time, is more definitive than the ability to move around on two legs.
However, one argument stamps this notion down: acquisition of food and the brain size are rooted in the occurrence of bipedalism. The ability to move around on two legs sped up the collection of food and, thus, enabled man's ancestors to go further in search of food, which, along with the regulation of body temperature bipedalism provided, led to the brain size and thinking activity of modern man.
V
Bipedalism can truly be considered as the most pivotal of all these occurrences, paving the way for further advancement in human morphology to what it is today.
Reference:
1. Leonard, W.R. (2002). Food for thought. In Evolution: A Scientific American Reader, 2006, 310-321.
(Pamela Francia is a student at the University of Asia and the Pacific, Pasig, Philippines. schizoavoidant@yahoo.com.ph)
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