Dominant and Recessive Genes

As I mentioned in my last blog I will now attempt to describe and help my readers to better understand how dominant and recessive genes work. This explanation comes from my own understanding of dominant and recessive genes, as described to me by my grade 12 biology teacher.

Every cell in our body contains a nucleus (or centre), where the instructions for our genetic makeup are held. These instructions come in the form of our genes. When we are concieved we recieve one gene from each of our parents for each specific trait we will have, in order to determine what types of traits we will have. Our parents carry two different genes for each of the specific traits that we will recieve. They can carry either a combination of Dominant/Ressessive, Dominant/Dominant, or Recessive/Recessive pairs of genes for any given trait in themselves. Our traits are dependant upon which of these two genes are passed on to us by our parents. The combinations of these genes can determine anything including our facial features, hair colour, height, and even wether or not we will inherit an illness. When attempting to understand inheritance you must also be aware of the fact that if a parent were to pass onto you a dominant gene you would recieve whatever trait they have passed on, regardless of if the other parent has passed onto you a dominant or recessive gene for that trait. This is because dominant genes always overpower recessive genes. The only possible way for someone to aquire a recessive trait is to have both parents pass on a recessive gene for that trait.


To explain this even further, I will give you a simple example of how dominant and recessive genes are able to appear in a child. This example comes from a diagram that I found on the following website: http://library.thinkquest.org/C0123260/basic%20knowledge/dominant%20and%20recessive.htm.




The Capital "N's and D's" in this diagram are used to represent a dominant gene while the lowercase "n's and d's" are used to represent a recessive gene. As you can see the mother and father are represented in each diagram. In the first diagram it is shown how it is possible for one to inherit two recessive genes. It shows that in order to inherit a recessive trait one would have to recieve a recessive gene from both their mother and father in order to aquire that trait. In the second diagram it is shown how it is possible for one to inherit a dominant trait even if one parent is only able to pass on recessive traits. If the parent with the one dominant trait passes on that trait it is inevitable that that dominant trait will show in the offspring no matter what gene the other parent passes on.

I hope I have done an acceptable job at explaining this process. This will come in handy when in my next blog I discuss how changing our genes could be beneficial to our health.

A Timeline of Genetic Engineering

I was searching for information regarding the topic of genetic engineering when I came across an article written on the BBC news website by Dr. Damien Carrington, that was of interest to me. It was written on May 30, 2000, and is called "The History of Genetics." It cought my interest because so far I have only written about genetic engineering and have negleceted to mention any background information on this subject. The Following is a time line of advancements made in genetics:

1869 - The chemical material DNA is discovered in cells.
1909 - The term "gene" is first used and the chemical composition of DNA is found.
1920 - Chromosomes are proposed as the mechanism by which inherited characteristics are passed on.
1944 - DNA is first connected to the inheritance of traits.
1951 - The first sharp X-ray diffraction photographs of DNA are obtained.
1953 - Crick and Watson describe the structure of DNA.
1956 - DNA is made artificially.
1966 - DNA is found to be present not only in chromosomes but also in the mitochondria.
1969 - The first single gene is isolated.
1970 - The first artificial gene is made.
1973 - Genetic engineering begins with the ability to insert genetic material.
1977 - DNA from a virus is fully decoded for the first time.
1976 - An artificial gene is inserted into a bacterium and, for the first time, works normally.
1978 - Bacteria are engineered to produce insulin.
1981 - A gene is transferred from one animal species to another.
1983 - The first artificial chromosome.
1984 - Realisation that some, non-functioning DNA is different in each individual - genetic fingerprinting is born.
1988 - The Human Genome Organisation aims to map the complete sequence of DNA.
1990 - The first human gene experiment takes place to try to treat a four-year-old girl.
1993 - Mice are cured of cystic fibrosis as a result of gene therapy.
1996 - After six years of work, the brewer's yeast genome is decoded, the most complex organism so far.
1998 - The first multi-celled animal has its genome decoded - a worm called C. elegans.

As you can see this list only goes up to 1998, but nevertheless it is astonishing to see the amount of progress that has been made in genetic engineering. The article also mentions in its beginning, a Moravian monk named Gregor Mendel, who is credited with being a "pioneer in the study of inheritance" due to his experiments on pea plants. In analysing seed and plant characteristics, and by following these traits through generations he discovered that some genes are dominant (more likely to show up in the offspring), and some ressesive (less likely to show up in the offspring). This was very impotant to not only genetics involving plants, but other life forms as well. This also is very important to the issue of genetic engineering, due to the fact that from Mendels experiments we may be able to identify which genes in the human form are dominant and resseive, therefore which genes will be passed on to our offspring.

There are many other scientists who can be accreditied to making advancements in the engineering of our genes, but I chose to mention Gregory Mendel as my next blog will be getting into the issue of the ability to change ones genes for heath specific reasons. His research is very important to this because of his discovery of dominant and recessive genes. In order to understand this better in my next blog I will provide a short explanation of how exactly one is to determine what traits their offspring may aquire.

The Fight to Leave Something to Change

One of the issues brought up in my last blog was the issue of having the ability to design ones own offspring to the a parents specifications. I was recently flipping through the February 23-39th issue of the New Scientist magazine when I came across an article entitled "Leaving Nothing to Change." The article, written by a man named Arthur Caplan is a critique of a book written by a Yale University Professor of ethics, Ronald M. Green, called "Babies by Design." The intent of the book according to this article was to discuss the abilities of parents to change the genetic characteristics of their offspring for future generations.

There are many key points made by Caplan in critiquing this book. His main argument reviews and debates the question of wether or not a parent should be able to engineer their unborn child. His argument is basically that the genetic engineering of an unborn child, and the genetic engineering of a child in general, is an unsound idea ethically when the human race is already facing current issues of disease and suffering in our children. Caplan also critques that fact that the only issue that Green adresses in his book is the process of genetic engineering and what it means for future generations. Caplan makes the point that rather than attempting to adress and fix our current problems, Greens only concern is of the power and ability to fix the future generations, rather than fix our current generations. It responce to this point it is only natural for one to question why our society would rather spend time fixing what is not yet "broken" than focusing on the current issues of our society at hand. Would it not be more efficient for human beings to make advancements towards improving the health and well being of our children now, and perhaps later attempting to "improve" upon our species?

This brings up another key point of Caplans, which states that the actual improvement of the genetics of our future children will most likely only be available to those who are "economically advantaged" and able to afford to be able to prevent defects and disabilities in their offspring. He says also that in being economically advantaged, one would be able to endow their children with enhanced traits and capabilities. This would prove to cause even more problems within our society (as an unfair advantage), by creating a heirarchy of people where the rich and their genetically engineered offspring sit at the top tier of the pyramid, while those who cannot afford to improve their offspring sit at the bottom of the pyramid, in disease, and without enhanced capabilities.

He also makes another sound critique about the book when he says that it is too risky to select a childs genes, and that they should not be treated as objects of manufature. He also says that they should be able to live their lives without feeling the need to complete their parents genetically enhanced expectations. The only thing that Green appears to be interested in when it comes to risks associated with engineering our children, is that it will go slowly rather than not at all. He believes that Green focauses too heavily on science in geonomics, stem cell research, gene therapy, preimplantation, and genetic diagnosis and does not contemplate the ethics that come with the creation of genetically enhanced children, including a genetically engineered childs worth.

In defence of Greens outlook, it is advantageous to move forward and attempt to perfect our species and wipe out disease in our offspring, but as Caplan points out there are too many current problems that are not adressed. You cannot advance into the future without at least adressing that there are in fact problems with our offspring at hand. It is now reasonable to wonder what dignity a human would posses if they were nothing more than an object of creation (almost a toy with which its creators are able to play with and use as they see fit). Green states that parents would still love their children regardless of how much they have invested into their creation, and regardless of wether or not they have lived up to their intended purpose. But one has to wonder how it would feel to have the weight of such expectations on ones shoulders, and having to bear the burden of anothers dissapointment when those expectations are not fufilled as planned. Would a person still feel loved if they had such a burden placed upon their shoulders, only to fail in the end. Would it also not feel like a burden to excell in something, but not have the desire to continue pursuing it other than having to because someone has invested so much into you being able to excell in something.

Another Good point is made by Caplan when he says that Green did not adress the fact that perhaps parents would begin to have no control over the creation of their children. He says that Green did not include the possiblity that governments may begin to impose standards of design on parents as well. Would this also not weigh heavily on a person, because they were created according to a specific mold, and are therfore only able to be what they have been designed to be?

I thought that this article brought up some excellent points. I, myself, am not here to impose my own certain opinion upon anyone. I will leave you all now to ponder what this article is saying and form your own opinions from some of mine, and Caplans observations.

To Change or Not to Change? That is the Question.

So Now that I have given you a brief introduction to the specific meaning behind genetic engineering, I will now introduce you to the Pros and Cons of such a process. Keep in mind that every action taken by human beings will naturally have both a favourable (or advantageous), and an unfavouable side to it. On the site www.ifgene.org it is said that the social process of genetic engineering is more of a debate than an actual dialogue, meaning that when looking at the issue there is no in-between, and that people will either be for or against it. The following are four main points from a website that are essentially the main points in the debates of those who are either in favour of or against the idea of genetic engineering in human beings.

(These sets of points come from the website: www.ifgene.org. They were written on April 27, 2001 in an article by a man named David Heaf. They are most likely a collection of debates considered by those who take interest in genetic engineering.)

PRO # 1:

• "With the discovery of DNA and unravelling the genetic code it contains, molecular biologists have finally come close to understanding what determines the form and function of organisms and can use this to design organisms at will."
• An advantage to this point is that with the discovery of how we are assembled, we may finally be able to understand our structure, and perhaps other stuctures of other organisms in doing so. This also brings up the point that we may, in the future, possess the ability to not only select favourable traits for our offspring, but also be able to change our own genetic structure.
  
• An obvious debate to this point would be the fact that the process of genetic engineering is not a natural process carried out by our bodies, and is therefore not ethically acceptable. In repose to this, would the act of breeding not in itself be an act of genetic engineering? Due to the fact that when seleting a partner, we generally choose one that has qualities and traits that are desirable to us (This point is brought up in the article as well when the Heaf says: "We have consciously interfered with evolution through breeding, habitat management and even selection of our own spouses for millennia without any noticeable dire consequences). Another debate that could be brought up would be that if we possesed the ability to change what we were, would alterior motives be involved in this process, other than perfecting our species?
  

PRO# 2:

• A quote from the christian bible states: "And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth." (Genesis 1:26)
• An advantage to this point would be that even in faith there appears to have been the knowledge that the human race was meant to evolve and change and have the ability to exist above all other species and alter them to their specifications.
• The debate to this point would be that the knowledge that the human race was meant to evolve and change existed, but it is whether it was meant to be natural or unnatural that is unclear. Nothing in this quote suggests that human beings should be subject to alteration in the future by any means other than breeding. In the article Heaf also makes the point in that by changing the genetic makeup of a person "Biotechnologists are playing God."
  

PRO# 3:

• "GE in the form of 'gene therapy' (somatic) could be used to repair damaged or replace missing genes in people who have genetic disorders such as cystic fibrosis, severe combined immunodeficiency etc."
• An advantage to this point is that in future generations we may no longer see flaws in our genetic structure, such a disease or defects. It could be possible to treat problems within or bodies efficently and efffectively.
  
• The debate to this point would be that it may not be possible to instruct genes to do a specific job, as genes are already created to do certain jobs. It would extremely difficult, if not impossible, for one to discover the exact chains of amino acids (used in the structure of genes, and can come in chains of 20,000) that may be involved in a certain body process. There is also the point that illnesses constantly evolve just as humans do, and in order to fight these new versions of an illness alternate genes would have to be created in order to avoid getting this disease.
  

PRO# 4:

• "Cloning might one day be combined with GM to create babies designed to meet the wishes of the parents. People could clone themselves or even lost loved ones from their DNA."
• An advantage to this point would be that people would be able to design their children to be the image of what they percieve as "perfection." Another obvious advantage is that human beings would not have to endure sorrow or pain due to the loss of a loved one. It would be as simple as pressing a button and recieving a new human being that resembled in all ways oneself, so that a person may live forever.
• There are many debates to this point. The first obvious debate being that it is unethical to create a human being with the selfish intent of creating that being according to ones specifications, and wants for that persons life, rather than letting them coose their own life path. People are both a part of heredity and the enviroment in which they live, so would great dissapointment not occur when a child created to be a basketball star, decided that they would rather play piano for a living due to the enviroment to which they are exposed. This would also be a debate to cloning oneself, as the self cloned would ultimatley be both a product of the genes from which they are created as well as the enviroment to which they were exposed after creation. A different surrounding enviroment, could ultimately lead to a different human being than the one that it was originally created from. This point could also work towards the recreation of a lost loved one. Theoretically we need to have an equal balance of pleasure and pain, and if it were possible to recreate our lost loved ones how would we be able to feel pain? One also needs to adress the issue that when looking a this point, would the constant pleasure that we recieve not cause us to be come more animal than human in the fact that we are selfishly denying ourselves of other emotions?
  

While there are many more debates out there that either take genetic engineering to be an advantage or disadvantage to our species, these four points will at least give you something to think about until my next blog.

Its All in The "Genes" You Wear

So now that I've introduced myself and the purpose for this blog, the next thing I should address is the actual topic of "Genetic Engineering."

When Looking at the composition of this phrase one might assume that Genetic Engineering refers to the building of genes. This is a fine definition, but what exactly does it mean? According to http://www.dictionary.com/ Genetic Engineering is "the development and application of scientific methods, procedures, and technologies that permit direct manipulation of genetic material in order to alter the hereditary traits of a cell, organism, or population." Thus meaning that Genetic Engineering is essentially an alteration or manipulation of genetic material (Genes) in order to obtain a specific desired trait in an organism, that can only be created (or removed) through the application of scientific methods, procedures, and technologies in this area.

Because of its definition Genetic Engineering is often confused with breeding. From a certain perspective is the manipulation of genes for our own benefit not in itself a non-traditional type of selective breeding? There is a clear distinction between the two, but at the same time is selecting something for its qualities not a direct definition of breeding? (I will go into further detail about this later, for now it is just to get people thinking about this aspect of Genetic Engineering.) Animals, Humans, and even plants are subjected to breeding for certain qualities. This being said perhaps Genetic Engineering can be better described as a higher, more evolved type of breeding.

There is much contreversy surrounding the manipulation of genes mainly from human rights activists, and many religions as well. In my next blog I will be describing the pros and cons of Genetic engineering. Until then think about what I have written, and Ill be blogging again soon.

Welcome

Hi Everyone,
This is essentially my first blog ever, and who would think that It would be for something school related? Currently I am enrolled in a university course called Contemporary Science, where we study many different aspects of science. For marks we have to write a blog about a topic of our choice. I have chosen to write about Genetic Engineering as I have found it to be a subject of interest to me, ever since we began to study it in my grade 11 Biology class. Throughout this blog I intend to not only explain exactly what genetic engineering is but also to show the positive and negative sides of genetic engineering, as well as how genetic engineering has affected the world as a whole. I hope my blog is of interest to everyone who reads it. So here I go. Enjoy.