Saturday, January 29, 2011

Sexual Selection

Sexual selection, for those who are not familiar with the term, is the mechanism used by the females to select the most genetically dominant males within a particular species for sexual reproduction. This selection is a means to promote favorable traits of survival on to the future generations. The males are in a constant and often aggressive struggle with one another to prove to the females that they are the most able and dominant among all the other males, i.e. the more genetically fit for survival.  Sexual selection is considered to be a part of natural selection, which can be understood as nature’s test to select the fittest. The term fittest in natural selection is an organism that has to ability to adapt quickly to nature’s harsh conditions and hence is more likely to survive and have offspring.

Examples of Sexual Selection in Nature and other Related Hypotheses
There is no denying that there are plenty of examples of sexual selection in the natural world. The mesmerizing beautiful feathers of male peacocks that are used to seduce the females are a great visual example of this mechanism in action. In other organisms, the females require the males to engage in more aggressive approach to show superiority in strength like with kangaroos, rams, or giraffes.
The Long-tailed Widowbird (Euplectes progne) © Isak Pretorius Photography
An emerging belief about sexual selection is that some females select according to “sensory exploitation” which means that females most often find exaggerated male traits attractive. For example, the larger the combs in the male goose, the more likely it is to be chosen as a mate by the females. Another example of this mechanism can be seen in the long-tailed widowbird of Africa, in which the females choose the dominant males according to their exaggerated tails. These long-tailed males are also more likely to be caught by the predators because of the long feathers. So this hypothesis was further expanded on by the handicap hypothesis, which stated that these females judge the superiority of the male according to its ability to survive despite these exaggerated traits that could potentially put it in harm’s way. 

Sexual and Natural Selection
Science today believes that this sexual selection is part of natural selection, because like natural selection, it encourages the passage of genetically dominant traits to the offspring. In other words, female sexual selection is directly related to the survival of the fittest. However, here lies the problem. This statement in detail means that female sexual selection is a selection of the males that are quick to adapt, as these are the ones that are the fittest and the more genetically favored to survive according to natural selection. So are these females actually choosing the ones that are quick to adapt as science states? Maybe we can test this theory by observing nature.

Eastern Bluebird
Let us look at the sexual behavior of the eastern bluebird, typically know for its monogamous relationships. A typical male fathers a certain percentage of chicks that are not related to it, either because it is unaware of female’s adulterous behavior or believes that at least one of the chicks might be related to it. There is no way for the male to figure out its offspring among other chicks, and so it is trapped taking care of all the female’s chicks. In a similar fashion, the male might be the biological father of some of the neighboring chicks. In this particular case of the bluebirds, the female chooses the mate that she wants to procreate with, and the male has the responsibility of making the nest for all the chicks.

The male bluebird (left) with a relatively dull-colored female (right). © FNAL (Fermi Lab)

 Now, let’s look at it in greater detail. First, the female chooses a male that it believes will be able to father its chicks. Then it goes around having affairs with other males that are more sexually appealing to it. These female bluebirds sometimes copulate with males that never even build a nest anywhere or fathered chicks. The original mate innocently provides for chicks believing that at least one of them is related to it. 
In this case, it is clear that the monogamous relationship husband can provide for the family by building a nest and is chosen to father all the chicks in the nest, but the female still goes around copulating with other males that are not good with building nests or as a father. The actual partner was clearly the more efficient in adapting quickly because it managed to build a nest from scraps and was able to compete with the other males by being faster in providing a home, when it was necessary. Since adapting quickly is key in surviving, the actual partner is the more genetically fit with the best traits. The male partner was also chosen by the female to father its chicks, which shows how the male has other genetically valuable traits that the other female’s lovers lack. Nevertheless, the females still mate with the unsuccessful mates that lack the fathering abilities and did not built nests, i.e. the ones that were not quick to adapt.
This is not in line with what is believed in natural selection. The female chooses males that might seem stronger, colorful, etc, but these have little to do with survival in nature. Nature is unpredictable, and so the best trait for survival is the ability to adapt quickly. By the term “survival of the fittest”, it does not mean that the strongest is the fittest, or the more colorful, but the one that adapts quickly because that is the one fit for survival.
Therefore, sexual selection cannot really be a part of natural selection because the female’s selection makes way for unfit male genes in the gene pool. These males are unfit because they are not good fathers and they cannot build a nest. The female is seduced by the color, tail, strength, etc of the male, but this is not as valuable for natural selection, which is all about the ability to adapt. The actual partner that fathers the chicks and is quick to build the nest, is the one that is more fit but gets the short end of the stick in this particular case.

Human Beings
The above mentioned case of the bluebirds can be found to be practiced among human beings and other organisms in a similar manner. However, there is another example of how sexual selection does not match with natural selection in human beings.

A human pedigree chart. © Prof Atsma 2005

            With human beings, an intelligent and educated family on average decides to limit itself to two or three kids. The educated family is more learned about available contraceptives and is more knowledgeable about the responsibility required in providing for a large family. On the other hand, an uneducated couple usually builds a much larger family. Either they are unaware about contraceptives or they do not think through about the possible consequences that arise from a larger family. In short, the educated woman gives birth to two or three kids, and the uneducated woman gives birth to much more. This shows how particular person’s sexual choices might have nothing to do with natural selection. The selection that occurs from one’s sexual choices in life is a limit that one puts on oneself and has almost no observable relation to promoting the fittest, which on the other hand is known to be the ultimate purpose of natural selection. Therefore in other words, natural selection and sexual selection are two unrelated systems of selection.

Related Supporting Articles:
"Women on "the Pill" Choose Better Dads as Mates, Study Finds." World Science - Science News. Web. 13 Oct. 2011. DOI: 10.1098/rspb.2011.1627

Saturday, January 15, 2011

About the Blog

This blog was made as an effort to question the scientific authenticity of modern researches and other related studies that are based on these studies. Science depends on such questions to improve, no matter who brings about these questions.
It is necessary to share such questions with whoever might be concerned; someone who can do something about it, empathize with the questioning, fix the possible misunderstandings, or even just wants to plain listen to them. Everyone is welcome to criticize it. It is solely revolves around the question: Are we following facts?

Why Question?
Science should not just be accepted but questioned, and questioning should be the most important part of science. This is what makes it different from erroneous beliefs. Every scientifically sound person wants to believe facts are set in stone, but is it true?
History has taught us several times that even the most basic foundational principles in the scientific world can be brought to question in light of new facts. Science is an ever changing and refining system that depends on such questions and new evidences. This is what is wonderful about science.

The History of Science
Anyone with a general curiosity about the history of science can search and find numerous revolution ideas that have occurred within the science community in the past, and learn how it threw out the old theories. This brings up the question: why does science have a hard time giving up old theories? This is a kind of human error and probably the number one factor that restricts the human population from making considerably more achievements and breakthroughs.
So what is this particular human error that restricts scientific development? It is the inability to let go of old beliefs. This restricting factor is what caused the rise and fall of the scientific community in history.  It is one that exists within a society and perhaps within each one of us. Eliminating this restricting factor or at least limiting it can help push the scientific world into the future.

Human Errors
Once a person accepts a fundamental theory that science discovers, he or she does not look for evidences to disprove it, but only to support and stabilize it further. In other words, some ideas can never be let go, and the more these ideas age, the harder it is to throw them away. Many scientists that know the history of science are fully aware of this kind of human error but for some reason refuse to realize that it is not a thing of the past. A true scientist wakes up every day, and questions all the things he or she believes to be true. Such a person tries to disprove their own beliefs repeatedly, and what they end up with, will more likely to be true.
Refusing to let go of old beliefs leads a lot of bias; such a person will refuse to accept valuable scientific discoveries because they personally don’t agree with it. This blog will try to be unbiased and different in this manner, and any bias noted will be brought to change. 
 A second kind of human error is concerned with keeping an open mind. The more beliefs we have that are not scientific sound, the more likely it is to be biased towards finding evidences that support them. So the next important thing is to keep an open mind. As Rene Descartes eloquently stated:

 "If when I don’t perceive the truth clearly and distinctly enough I simply suspend judgment, I am behaving correctly and avoiding error. It is a misuse of my free will to have an opinion in such cases: if I choose the wrong side I shall be in error; and even if I choose the right side, I shall be at fault because I'll have come to the truth by sheer chance and not through a perception of my intellect."

Science does not accept things because it is better than all the other ideas. It should only accept theories that are scientific. Otherwise, science holds no power than any other set of beliefs. Pure science has nothing to do with how profitable a finding can be, how the findings will effect the society's beliefs, assumptions, or any personal bias. However, this is not the case in reality.

Effects on Society
These days, any research or study done by science is widely accepted by the general public. The general public rarely reads these scientific research papers to check for inaccuracy in the conclusions, sample size, etc or see if there is repetition, or improper instruments used while conducting these researches. Most people blindly accept that the scientists are well educated men that are careful with their studies and never make mistakes. These people are being taught that these studies are always repeated infinitely by many other scientists and also supported by numerous other similar researches and studies. The general public is also not well-informed in scientific principles to understand the experiments in the study like about how the scientists came up with the conclusions, but are only concerned about whether it affirms or denies their beliefs. This is not an attempt to belittle the general public but merely an observed effect of science on people.
It is human to hold strongly to one's beliefs and the longer people accept a theory, the more stubborn they become about changing these theories. On the other hand, science cannot be stubborn with its beliefs, as science is every changing and if science starts getting stubborn, then it can heavily limit the progress possible through science.

Examples of Human Errors
The scientists who research and conduct these experiments are human beings like the rest of us. This means that their bias and beliefs affect the scientific study. The more they decide to hold on to a particular belief in science, the less likely it is for the study to find something outside of the scientist's beliefs.
One can see examples of these errors by reading on Galenism, or reading about how the early Catholic Church reacted to the heliocentric model of the Earth going around the Sun. The actual error here is not religious beliefs, but how people cannot let go of their old theories of the world. As explained before, the longer those theories exist, the more stubborn people get about leaving those theories behind.

The Purpose
This blog site was created to take these experiments one-by-one, in most cases, and question the basic ideas and biases behind it. Many scientific studies never get repeated unless fellow scientists find it questionable. This leaves a large area for error because if all the scientists agree on the fundamental ideas, then no one questions it and it never gets repeated and alternative ideas are never considered.
It is believed that only scientists and experts can only question scientists. This seems more illogical than when only the Church priests could read the Bible, or question the selling of indulgences and the people were to blindly follow the teachings of the Church.
Scientists should be able to say 'I don't know' if they don't know something, rather than make up the best lies and correct their theories every time somehow to make sense of the new findings. This case can be seen with the M theory, which has not much observable evidence to support it, and many scientists even consider it to be purely philosophy. Beliefs without evidences are merely beliefs, and should not be given any extra importance because those beliefs belong to a scientist. Instead, a scientist’s beliefs should only as good as the evidences he or she has to support the beliefs.

Not all the scientific questioning on this blog has a valid point. In other words, the author does not claim that all these questions are right and so it is possible that most of this blog might not even have any scientific substance. This blog only means to help others keep an open mind towards similar things, and so it is left to the readers to accept or neglect these questions. It is not an "all or nothing" situation with these questions, as each of these questions on the blog are meant to stand on their own and does not depend on other arguments on this blog.