Responses to Five Articles about Genetics

These are exciting times for the human race.  Our technology is improving at an incredible pace; it’s hard to believe that neither computers nor the Internet were widely used 20 years ago.  Genetics is another field which is experiencing unprecedented growth.  Ten years ago, scientists finished transcribing the human genome; we now have a blueprint for human life.  Each week, we hear more news about DNA and what we can do with it.  Already, DNA evidence has become a key component of criminal cases; what if we could have had it in the thousands of years of jurisprudence before now?  Thanks to transgenic crops, we now eat bigger and better food than any society has before.  Who knows what future boons genetic engineering will bring?

I believe that the press wants to report about this topic accurately, but at the same time, each reporter wants his stories to be the most important and most-read pieces in the world.  Thus, our scribes are given to hyperbole, particularly in their headlines, when they report about controversial issues such as genetics.  For example, one article which I used for this portfolio is called “A (Genetic) History of Violence.”  This is a broad, sweeping title, a clear reference to a dramatic movie which was released this year, but the article’s content is much less ambitious.  It tells us of a certain gene, some of whose alleles are mere risk factors for aggressive behavior.  The article is still useful, but it does not deliver all that it promises.

Biology 48 has given me the facts I need to discuss genetic controversies and to evaluate articles on such subjects.  I can now combat the ignorance that so often masquerades as common knowledge.  I can now read more complex articles about the field and understand them.  Simply put, Biology 48 has given me genetic literacy.

Of the articles I read, “A (Genetic) History of Violence” affected my view of the connection between genotype and brain activities.  I have heard of people having “chemical imbalances” which affected their thoughts and decisions, but I did not understand how these states could have genetic components.  “A Transgenic Threat to Indian Crops” made me seriously consider the consequences of crop contamination.  Without this article, I would not have realized that transgenic crops are such a threat to indigenous food and culture.  “The Sad Lot of Lab Chimps” helped to show me the effect that comparative genomics could have on the use of animals in laboratory research.  “’X’ Factor Boosts Women’s Health, Longevity” supplemented my knowledge about X-linked traits and lead me to wonder about the future of the Y chromosome.  “Anyone for tennis, at age 150?” helped to show me the present and potential future of genetic research.  It also reminded me that some people in the world are putting too much of their hopes in this field as a means for solving humanity’s problems.  Genetic research can change details of our lives, such as our susceptibility to certain diseases, but it cannot change basic facts about humanity.  Humans will always joke, laugh, fight, love, weep, choose their own destinies (often after days or years of soul-searching) and die.  I would like to believe that no amount of genetic engineering can change that.

“The Sad Lot of Lab Chimps” by Jane Goodall and Ray Greek

The Boston Globe, 17 February 2006

Science Terms

Comparative genomics the comparison of the genomes of different species and races.  Through this process, we can patch together the evolutionary connections between different organisms because genetic mutation is such an important part of evolution.

Genome/Genotypethe genetic sequence of an organism.  This provides the blueprint for the organism’s growth.

Phenotype – the physical expression of an organism’s genotype – in other words, the organism itself.

Summary

Jane Goodall and Ray Greek wrote this editorial to protest the use of chimpanzees for medical research, particularly in painful processes such as “infections with human pathogens, vital-organ biopsies, repeated inoculations for vaccine testing, and transfection for virus production.”  Goodall and Greek argue that recent advances in comparative genomics, particularly the completion of the rhesus macaque and chimpanzee genome projects, have proven that such procedures are useless and unnecessary because primates and humans have too many biological differences.  At least 5% of their genotypes are different, and their phenotypes are even more different.  Because the phenotypes of identical twins can diverge so much, the phenotypes of two separate species which grow up in totally different environments would be even more different!

The authors note that primate experiments with HIV-AIDS and hepatitis C have added little to our body of knowledge.  Primate research helped lead to the hepatitis B vaccine, but the use of primates for this purpose is now obsolete.  Goodall and Greek say these projects are not just ineffective; they are also unethical because primates are sentient beings.  The authors make many efforts to anthropomorphize these beasts, including describing their behavior, their mental prowess, etc.  Surely, they say, scientists should find a better means of learning about humans than doing research on chimpanzees.  “If we look into the eyes of one of these [caged] chimpanzees, shall we not feel deep shame?”

Response

As a Christian, I believe that humans and primates are fundamentally different entities; the former has an immortal soul, while the latter does not.  Therefore, I am not concerned about killing animals in order to save humans.  Since we are also stewards of the Earth, however, we should be careful not to capture, infect, and kill animals without good scientific reason to do so.  Thus, I am sympathetic to Goodall’s and Greek’s argument that the ends of this primate research do not justify the means.  However, genomics is such a new field, about which we know so little, that I seriously doubt we have conclusive evidence that primate research will not benefit humans.  Remember, it was research on mice that lead to the discovery of DNA.

“A Transgenic Threat to Indian Crops”

Sindhu Manjesh, CNN-IBN, 27 March 2006

Genetics Terms

Restriction enzymes – An enzyme is a complex protein which catalyzes a physical reaction.  Restriction enzymes cut DNA which include certain specific sequences.

Transgenic crops – These are crops whose genes have been modified with recombinant DNA.  Scientists use genetic markers to find the part of a plant cell’s genome which they want to modify.  They cut the desired DNA strand with restriction enzymes, introduce foreign DNA fragments with favorable qualities, and then mix the DNA with enzymes to seal the pieces back together.  The cell then divides into several cells, which eventually form embryos and then whole genetically modified plants.

Genetic contamination – The pollen of transgenic crops, like the pollen of other crops, can travel for several miles in any direction.  If it falls on a field of indigenous crops, it will cross-pollinate with them; since it is genetically enhanced, it is more likely to survive and thrive than the pure offspring of indigenous plants.  Thus, over several generations, genetically modified plants can destroy several indigenous varieties; this is “genetic contamination.”

Summary

Indian Prime Minister Manhoman Singh wants to revitalize Indian agriculture by expanding the use of genetically modified crops in India.  More than 40 varieties of transgenic crops are waiting for approval from the government.  However, CNN-IBN has uncovered problems with the government’s review process: (1) it is dependent on the research of the very companies who are peddling the seeds and does not even know where the tests are taking place; (2) many of the farmers who are undertaking these trials are violating several trial guidelines; (3) farmers are not properly protecting transgenic crops from cross-pollination with indigenous crops.

Response

I am not concerned that transgenic crops carry health risks because I don’t see a compelling scientific reason why they would.  Modifying a crop’s genes seems to be just like cross-breeding species to accentuate certain traits.  However, I am concerned about genetic contamination.  First of all, if one farmer’s transgenic crops decimate another farmer’s indigenous crops, it is a case of property damage and merits fiscal restitution.  Second, the less agricultural variety we have, the more vulnerable we are to famine: a pest or pathogen which is especially potent against a certain variety of plant could wipe out an entire crop.  Third, a decrease in food variety diminishes the richness of a culture.  Also, the Indian government’s abject failure to regulate transgenic crops or to even keep tabs on the trial process is troubling.  A government which cannot enforce its laws may as well not pass them.

“Anyone for tennis, at age 150?”

Ronald Bailey, Times Online (UK), 8 April 2006

Genetics Terms

Embryonic stem cells – Stem cells are cells are pluripotential; in other words, they could change into any of several different types of cells.  Embryonic stem cells are the cells that make up a blastocyst (human at about 8 days’ development).  They have nearly limitless potential for change, so many scientists are trying to determine how to shape these cells to their wills.

Genetic marker – a DNA sequence with a known location and function.

Mitochrondria – the organelles in the cell membrane which produce energy.  Scientists think that aging occurs when they are damaged.

Pre-implantation genetic diagnosis – In this process, several embryos are produced and screened for genetic diseases.  The embryo which is healthiest and carries the least genetic risks is then implanted into the mother for birth.

RNA interference – dsRNA, a mixture of sense and antisense (scrambles RNA) DNA, is injected into a cell.  Because the RNA is scrambled, the cell cannot express these genes.

Sirtuins – compounds which delay aging in simple organisms.

Summary

Ronald Bailey argues that within 100 years, people will live in a world in which people can live 200 years (perhaps forever); eat food which contains all nutrients and which prevents aging; have immunity to most diseases; re-grow their limbs and vital organs; take genetic treatments for mental diseases, and enjoy a cleaner environment due to advances in genetic engineering.  Bailey then runs through the current research projects of several biotech companies.  Among the things these researchers wish to do: (1) successfully use sirtuins in complex organisms and how to improve mitochondria; (2) repair and replace organs using stem cells; (3) use RNA interference to turn off genes which damage us.  They also are trying to find genetic markers for various traits in plants and animals.  Once they are found, we can genetically enhance traits such as resistance to diseases, strength, intelligence, and so forth.

Unfortunately, left-wing and right-wing “bioconservatives” are trying to prevent this perfect world from coming to be because they have moral reservations about certain bioengineering procedures.

Response

This piece was a good primer for the advances in biotechnology over the past few years.  Its tone greatly worried me, however.  It would be acceptable if Bailey had merely argued that genetic engineering could improve our lives, but he seems to sincerely believe this technology will create a perfect world here on Earth, and I strongly disagree with this point.  First of all, his article says nothing of natural disasters, cancer, automobile accidents, and other causes of death which we have been powerless to stop so far.  Second, no matter how much control we take over nature, even if we can treat mental illnesses with genetic remedies, we cannot wipe out the evil which resides in the hearts of men.  According to the US Department of Justice, only 16% of American criminals have mental illnesses.  “Normal” people get into fights and hurt each other’s feelings every single day.  Genetics are not the cause or solution to all social problems.

Finally, I can’t help thinking about old 1970’s and 1980’s articles I have read which intimated that computers would eventually eliminate the need for human beings to work so we could spend all our time on leisure.  The year is 2006, and computers have certainly changed the world, but it seems to me like most people, even children, are working harder and longer than they ever did before.  As Robert Burns said, the best-laid plans of mice and men often go awry.

I find it ironic that Bailey calls the party which favors any and all genetic research the “party of life” since some of its opponents call themselves “pro-life.”  The objection with which I sympathize the most is the argument that embryos are human lives.  If this is true, then producing and destroying them for science or for any other purpose is a grave violation of human rights.  The ends would not justify the means.  Rather than directly confronting this argument, Bailey counts on the majority of his peers to discount it as backwards.  This is probably for the best because the “Is it a human or isn’t it” debate almost always ends in an impasse.  Time will tell whether the Bailey’s “party of life” or the “pro-life party” wins the battle over government policy.

“’X’ Factor Boosts Women’s Health, Longevity”

Dr. Barbara R. Migeon, Kansas City InfoZine, 22 March 2006

Genetics Terms

X chromosome inactivation – Cells typically express genetic information from only one X chromosome.  Since women have two X’s, the cell “inactivates” one of them so it can express the other.  Cells seem to decide randomly which X to use.

X-linked genes – genes which are only found on the X chromosome.

Mosaicism – Because cells decide randomly which X chromosome to activate, a woman’s body is a roughly even mixture between cells which express her father’s genes and cells which express her mother’s genes.  Thus, she is a “mosaic,” and this phenomenon is “mosaicism.”

Summary

This article details the current scientific opinion about the relationship between X and Y chromosomes.  A woman has two X chromosomes, so if one of her X-linked traits contains a negative mutation, the matching allele on her other chromosome can diminish or suppress it.  If she passes the mutated X chromosome to her son, though, he cannot protect himself against it because he has only one X chromosome.  This is why males are much more likely than females to inherit debilitating X-linked conditions like Duchenne muscular dystrophy and hemophilia.  Other diseases, like incontinentia pigmenti, kill men almost immediately but merely cause deformities in women.

Scientists are also investigating the effect of sex-linked chromosomes on personality.  Men and women have documented differences in their senses of humor, so geneticists wish to find the genetic markers for this trait.

Response

I have heard much about the diminished state of the Y chromosome, but if it actually carries less than 100 genes, they must be very important genes because men seem to inherit many traits, most obviously large portions of their physical appearance talents, and personality, from their fathers.  Otherwise, I have no qualms with this research.  This sort of research does not embarrass me.  It means that the men who did survive are the strong ones.  I am only worried that the Y chromosome will deteriorate so much that men will become impossible.  Could evolution really lead our species to total destruction?

“A (Genetic) History of Violence”

Michael Balter, ScienceNOW Daily News, 20 March 2006

Genetics Terms

Allele – a possible variation of a gene.  Different alleles lead to different phenotypes.

Genetic marker – a DNA sequence with a known location and function.

Genome/Genotypethe genetic sequence of an organism.  This provides the blueprint for the organism’s growth.

Phenotype – the physical expression of an organism’s genotype – in other words, the organism itself.

Risk factor – an allele which makes a person more susceptible to a certain condition but which does not ensure that he will suffer from it.

How do genes produce enzymes?

Transcription­ – The DNA double helix opens so RNA polymerase can enter and bind to the DNA at a “promoter region.”  The DNA unwinds, copying itself to the new “messenger RNA” (mRNA).  When the sequence terminates, the mRNA eliminates unnecessary sequences (exons, whereas introns are necessary) and leaves.  The double helix returns to its normal state.

Translation – mRNA enters the cytoplasm.  There, the anticodons on tRNAs recognize sequences (or codons) within the mRNA and attach to them.  The tRNA produces proteins/enzymes according to these given instructions.

Summary

A recent study from the National Institute of Health at Bethesda, MD has linked violent behavior to the enzyme monoamine oxidase A (MAO-A).  During stressful times, the brain produces much serotonin, norepinephrine, and dopamine, neurotransmitters which trigger emotions.  MAO-A breaks down these substances so that the brain can return to its normal state.  Different alleles of this gene produce different levels of this enzyme.  A previous study linked low MAO-A levels to men with traumatic childhoods who express antisocial behavior.  This one sought to broaden the known link.

The Bethesda team studied the brains of 142 subjects, screened for mental health as a control against other genetic and social factors which could negatively affect phenotype.  They found that subjects with low MAO-A levels had much more active amygdalas, and the segments of their brains which control emotions were on average 8% smaller than the rest.

Other scientists lauded the researchers’ work.  They also suggested studies on mentally ill subjects to show a connection between low MAO-A and actual aggression.  The Bethesda team was quick to note that MAO-A is but one of many risk factors for aggression and that individual choice is still the most important factor.

Response

I think this is an intriguing study.  Its premises and conclusion seem entirely plausible to me.  I am also pleased that Andreas Meyer-Lindenberg and Klaus Peter-Lesch, two neuroscientists interviewed for the study, contended that “Genes are not destiny.”  This dovetails with my opinion that free will is the leading factor in any person’s decision.  Our genes set our internal environment, but we can still choose what to do about them.

Explore posts in the same categories: Schoolwork, Science, Math, Technology

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: