Arresting Development

The Dark Side of Science

I confess that one of the reasons I was attracted to the study of biology and chemistry is that I would always be right.  I would know how the universe works.  I knew that via the scientific method (ensuring that all experiments involved years of study, multiple trials, and approval from a committee of nerds) I could solve all of the world’s problems, and end all arguments. If I got into a dispute with anyone, I expected that just by saying “science”, I would automatically win.

However, my assumptions that science was untarnished (at least, by moral ambiguity) came to an abrupt halt by the time I entered college.  I soon realized that there are a lot of ethical issues with regard to experimentation.   Animal testing, in particular, has led to various breakthroughs in medical research, but is still on shaky moral grounds.

I remember, way back in the summer of my sophomore year, reading a book by neuroscientist Joseph LeDoux. I learned many things:

1. That I do not apparently understand the concept of summer vacation…
2. …a comprehensive look at the brain is organized and how this makes us who we are…
3. ...this experiment:

In an effort to associate various regions of the brain with their behavioral functions, neurobiologists induced lesions on the brains of cats.  Cats that were given lesions on their forebrains, they lost their problem-solving skills.  Cats that were given lesions on their midbrains, they still maintained bodily functions, but were comatose.  Cats died when they were given lesions on their hindbrains.

Through this experiment, scientists reached the conclusion that the forebrain has the function of problem solving and personality, the midbrain, of sleeping/waking, and the hindbrain, of essential body functions.

However, my first conclusion was a slightly more profane version of “scientists are blackguards”.

This sentiment tends to pop up throughout my educational experience.  I know that empathy for other species is (probably) not evolutionarily selected for.  (I mean, we got these giant brains of ours from eating animals, right?  It must be true because Science said it is!  It has a link and everything!)  I also believe that there can be little understanding how organs, and systems work without some experimentation on live animals.   However, sometimes, one has to wonder if the millions of sacrifices they make are worth the benefits to humankind.

Of course,  we will never know just how many animals are used in experiments. The Animal Welfare Act drafted in 1966 lists dogs, cats, guinea pigs, and primates as animals entitled to legal protection, a daily dose of positive human interaction, and minimum cage requirements.  However, it explicitly excludes birds, rats, and mice, as well as cold blooded animals such as reptiles and fish.  As of 2006, 66,314 dogs, 21, 367 cats, 204,809 guinea pigs, and 62,315 apes and monkeys have been registered at research laboratories across the nation.  They are checked periodically to ensure that they are treated humanely while some 100 million mice have no such recognition.

Keep in mind, mice have been bred for some research studies.  Transgenic mice, and knock out mice are incredibly useful for mimicking human diseases, such as diabetes, and Alzheimer’s.  Is it cruel to kill mice that would otherwise not survive in natural conditions?  Is it cruel to breed them in the first place?

Many would say it is.   The following link is to a PETA video decrying animal testing.  They raise the counterarguments that while inhumane, animal research is also irresponsible, since successful tests on animals does not necessarily translate into successful human therapies.   (Animal tissue is apparently different from human tissue, and yet both have the capacity to feel pain.)  Furthermore, human tissues can easily be gained from stem cells which… jettisons me into another debate.

But I can’t argue with that premise.  For scientists, there are many systems available on which to conduct research.  Furthermore, the video claims that it is wrong to perform research on animals just as it is wrong to perform research on humans.  Because we have.  But I find it interesting to note that the Animal Welfare Act came in to play  8 years before the  National Research Act was made to protect the rights of humans in medical studies.  The Act was drafted two year after the exposure of  the Tuskegee Syphilis experiment.  (In this 40 year experiment, over 400 black sharecroppers were untreated for syphilis so that doctors could understand the effects it had on the body.)

Reading this brought me to a forgone conclusion.  I cannot sympathize with animals with the same ease as I sympathize with humans.  Reading about animals as research subjects makes me feel somewhat guilty, and a bit sad.  Reading about the Tuskegee Syphilis Experiment, etc.  (seriously, there is a rather large Wikipedia page entitled “Unethical Human Experiments in the United States”) could very well give me nightmares.

In short, the ethicalness of using animals for research depends on how close we believe they resemble us.  There is much more concern for animals that are considered related to us. The Animal Welfare Act protects, to some extent, animals that are common pets (and often considered members of the family).  It also protects primates because they genetically and phenotypically resemble us the most.  Subjugating them to experiments is hard, because we see ourselves in them.

So we are somewhat less monstrous for research on other animals.  I might be safe in my confession that I have committed experiments on animals (unprotected by the Animal Welfare Act).   The species I worked on was Drosophila melanogaster, also known as the fruit fly.  And from my perspective, they were adorable.  I even gave them names.  Admittedly, all of them (including the females) were named George.

However, most people don’t find fruit flies adorable.  And if they did, they would notice that fruit flies are only cute when they are adults, which is really the reverse of other animals.  For instance, imagine your response to seeing a Doberman puppy versus a full grown Doberman.

 

A puppy is approached with a certificate of adoption, while a full grown Doberman should always be approached with caution.  Whereas the fruit fly is usually met with a newspaper.

 

 

 

Special thanks to Hal Herzog, Author of Some We Love, Some We Hate, Some We Eat, for the inspiration, and some factoids.

Why Development?

Biology is a beautiful and diverse science that contains many fields, applying to all creatures great and small.  Of these myriad subjects, developmental biology is one of the newest, and least understood.  So many people might ask: why study development?

Development can be summed up as a combination of genetics and embryology.  While genetics is a fairly recent breakthrough, embryology had its origins as early as the 17^th century.

Anton von Leeuwenhoek, also known as the father of microbiology, was a cloth merchant by trade.  He depended on glass lenses to keep track of the thread count of his fabric.  His practice of grinding lenses led to a love of making microscopes, and he was able to create a model that could magnify up to 230X.  This microscope was far too compelling to look at fabric all day, and Leeuwenhoek took examining whatever he could with it:  rainwater, blood, etc.  In 1677, a letter from the Royal Society of London requested that he find out what was contained in semen.  He was shocked to find that it was alive with tiny wriggling things.  At the time, scientists had already accepted that the semen was required to generate life, but they essentially didn’t what it was.  Cell theory wasn’t universally agreed upon until 1839, and until then, many scientists assumed that a sperm consisted of a tiny little human (also known as a homunculus) encapsulated in a pod with a long tail.

Interestingly enough, it took until 1827 for Ernst von Baer to discover the first ovum.  It wasn’t until 1843 that scientists found out that both a male sperm and a female ovum were required to generate a new organism.

Two particular experiments in the 19^th century confounded embryologists for a while.  Wilhelm Roux found out that if he allowed a frog zygote (an egg after fertilization) to divide once, and he destroyed one cell, the other cell would grow into half of an embryo.  Whereas Hans Driesch found that repeating the experiment on sea urchin zygotes resulted in a full, if smaller, embryo.  In 1924, Hans Spemann, and Hilde Mangold discovered that some cells could be induced to take on special characteristics if they were in proximity to an organizer –a small part of the embryo that organizes the creation of the embryonic body.

But development really took off in the 1940′s when it was discovered that proteins were encoded by genes.  Since scientists knew that a cell’s form and function depended on the proteins it made, it was decided that altering the expression of a gene could alter the physiology of a cell.  Further insights into cell differentiation occurred when it was discovered that some proteins had the role of regulating the creation of other proteins.

Essentially, what fascinates developmental biologists is what happens after a sperm and an egg (which presumably love each other very much) conjoin.  As we know, the fertilized egg will divide into thousands of cells, each one looking like the other, and containing the same DNA.  However, after a period of time, these seemingly identical cells will change in appearance, and  physiology, and perform extremely specific tasks.  Some  cells will become neurons, some will become skin cells, and others will become muscle fibers.  A developmental biologist uses genetic information to see how cells communicate to each other, and how they determine their own characteristics.

It is hoped that through genetics and embryology, a developmental biologist can piece together the puzzle that begins with two germ cells, and ends with the miracle of a complete organism.