Even with seemingly simple things like eye color, you can’t tell from my genetic code whether I have blue eyes or not. So it’s naive to think that complex human behaviors, like risk-seeking, are driven by changes in one or two genes.
~ Craig Venter
Human Genome Project
In last week’s blog, I mentioned that I had gotten into a brief discussion with a friend while at a wedding reception a few weeks ago.
She was arguing that certain human characteristics were predisposed by hereditary traits...
...while I was, on the other hand, arguing that facts, opinions and beliefs were all very different entities (see last week’s blog where I talk about this in detail) .
It was the classic example of two people talking (in the same language)... but not really comprehending what each other is trying to say.
The really interesting part was that I completely agreed with her general hypotheses... that there are indeed genetic markers, that when expressed, can cause humans and other living species to exhibit certain properties and behaviors.
After the episode at the wedding, I decided it was time to learn a lot more about our genetic make-up and what scientists currently theorize might be happening at the cellular, molecular, and/or atomic levels in our bodies.
First let me first start with a disclaimer... I’m an electronic engineer... not a genetic engineer or microbiologist... therefore... the complex information I’m sharing with you today is very much an over-simplification... in a field where our knowledge base is growing each passing day... and what we know today may be found wrong tomorrow.
Our human bodies are made up of cells... about 37 trillion cells to be somewhat exact (yes trillion with a "t").
A new being is created when the reproductive cell of the female of the species is connected with the reproductive cell of the male of the species.
In a human reproductive cell (male and female), there are 23 chromosomes. When the two reproductive cells are connected, each of the 23 chromosomes find their mate to create 23 chromosome pairs (46 total chromosomes).
Chromosomes strands are made up of complex molecules called DNA strands organized in a double helix configuration and wound in tight coils.
There are 4 basic building blocks called nucleotides that make up the DNA (abbreviated as A, T, G, & C). Millions of these basic building blocks are arranged in such a way as to create a distinct structure.
Imagine that instead of the 26 letters in our English alphabet... there were only four letters... and with only those four letters... thousands of different words need to be created... those thousands of words would need to be long and complex to achieve this task...
The words that are created using those 4 letters are called genes.
Each human cell has approximately 20-25 thousand genes residing on the 23 pairs of chromosomes (scientists are unsure as to the exact number of genes... as unlike our written language... there are no spaces in between the words so it’s hard to distinguish where genes start and stop).
Each and every person, presently and historically, on earth has a unique set of genes... so in essence... we each have our own unique story using different words.
That is not to say that many of us don’t have similar gene structures since your genes are passed onto to you from your parents based on their gene structure.
The primary purpose of a gene is to create a complex molecule called a protein which is made up of smaller molecules called amino acids. These proteins give operating instructions to the cell nucleus in which the chromosomes reside.
There are 20 different types of proteins that a gene can create depending on the type of cell (such as blood cells, skin cells, bone cells, hair cells, etc.).
Only about 1.5% of the 20,000 genes in each cell are creating instructional proteins for that particular cell at any given time. The rest of the genes are sitting there doing nothing.
The genes that are actively working are considered "expressed"... where the genes that are inactive are considered "repressed".
Genes can be turned on (expressed) or turned off (repressed) at any time due to a variety of external factors, such as diet, stress, sleep, age, and/or exercise.
Scientists from all over the world have been actively working to map the human genome in order to try and isolate the location and purpose of each of the 20,000 genes found in each cell in the body.
Within the last 5-10 years, researchers have discovered specific genes that are responsible for certain characteristics.
For example, doctors have located the BRCA1 and BRCA2 genes. The BRCA genes are essential in helping to repair damaged DNA. If the gene becomes mutated (there are over 100 different mutations of this gene) there is a significantly higher risk of a person developing cancer (especially breast and ovarian cancer).
While it is true that those people who possess these particular genes do indeed have a higher health risk, only a very small percentage of the population overall actually has a mutation of this gene... and those who do have this gene, only about 7% of them actually develop cancer... however if a person does have a family history of the mutated BRCA gene, then it is 50% more likely that they too will have the mutated gene... and with it... a significantly higher risk of cancer.
So what does it all mean?
The take-away this week is that although each of us are very unique individuals and there is no one exactly the same as us, past or present, we still share many of the same human characteristics with our family, friends, colleagues and neighbors.
And in fact, we share many of the same genes and chromosomes with all living creatures (while doing research for this blog, I discovered that humans share about 40% of our genetic make-up with a common fruit fly and 50% with a banana... yes... a banana!!)
The other take-away is that although there might be some correlation between genetic structure and expressed human characteristics... there is simply only a probability that this characteristic will actually occur.
If a man was born with a male-pattern baldness gene... it doesn’t mean that there is a certainty that the person will end up bald... there is only a probability that the gene will actually become expressed and that he should start investing in hats.
My path in life has met up with some people who claim that they are genetically predisposed to some type of behavior because it "runs in their family".
This might include the inability to concentrate (ADD), the supposed ability to readily function on only 5 hours of sleep each night, an addictive behavior, and/or the inability to make good choices (impulsive or reactive personalities).
This could indeed be the case.
There is a definitely a genetics component involved... if one indeed has the gene present and it is expressed... however it has also become a ready-made excuse for those who don’t have this gene and are unable to accept responsibility for their actions.
"Don’t blame me... blame my genes", they cry.
...and even if the gene is present... we still have an opportunity as to whether or not to act upon these behaviors.
Which leads me right back to how the original discussion started in the first place...
Everyone seems to have an passionate opinion on this subject... so now I’m waiting for your contribution to the discussion.
Thank you for your support of OptiFuse where fuses and circuit breakers might not be in our blood... but we do believe that we are genetically predisposed to provide you with great customer service.
Jim Kalb President
Email - firstname.lastname@example.org
Website - www.optifuse.com
Twitter - @OptiFuse