Gapay, A. (2008). Faster cheetahs are better?

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)

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)