Tuesday, October 26, 2010

Life lines 9


Many people for millennia have contemplated themselves, seeking some inner truths through contact with the divine or some sense of self. I tried that about sixty years ago and found it led me nowhere, a reflection, no doubt, of my scientific habits of wanting to know what is going on. But I do enjoy contemplating myself in a different way to enrich my sense of who I am. At the level I can share with almost everyone reading this, I am a melting pot American, a scientist, a writer, a historian, a devoted husband, a father, and grandfather. I am a male and that means I have a Y chromosome which set off a set of events when I was a 50 day old embryo that gave me testes and male genitalia and flooded my fetal body with testosterone pushing me into a gender I identify as male. I was also among the 90% of humanity that was fertile. To an anatomist or coroner I would be a series of systems – skeletal, circulatory, muscular, nervous, and epidermal with a variety of internal organs necessary for life like lungs, kidneys, liver, and digestive organs. To a histologist I am a collection of tissues –nerve, muscle, connective, epithelial, and germinal. I am also a colony of about ten trillion cells. Each cell has its own collection of organelles to contemplate—a cell membrane, mitochondria, lysosomes, a spongy network in which protein synthesis takes place, and a nucleus with 46 chromosomes.

Those 46 chromosomes contain about 25,000 genes from which my enzymes, structural proteins, and on-off gene switching signals are produced. The enzymes digest molecules into simpler forms and they stitch together other molecules to make larger complex molecules. Of the 92 natural elements found in our universe, most of my body is made of carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorous, with a generous pinch or so of iron, potassium, chlorine, sodium, zinc, and copper. Those rarer trace minerals are largely used to make my vitamins work. If I were to count all the atoms in my body they would be in the neighborhood of a one followed by 26 zeroes, a number that exceeds all the stars among the 100 billion galaxies in our universe.

It is a heady contemplation to be composed of matter aware of itself. It is also fun to contemplate that my 25,000 genes can be traced to ancestors in Sweden and Ukraine today but also back to Europeans coming out of the Middle East and eventually out of Africa some 60,000 years ago. If my genes could talk they would identify which ancestor, among many thousands, contributed each specific gene to me over the past few thousand years. Because I am a scientist well versed in how biology and evolution works, I would know that my vulnerabilities are not limited to my psyche in times of crisis, they are the fabric of life itself – the integrity of my chromosomes and genes that I have passed on to my children and that are besmirched, here and there, with past mutations we drag along like bad dreams and that emerge here and there across the generations like recurring nightmares. Like Walt Whitman’s phrase in his song of himself, “I contain multitudes,” and I share with that poet the tens of thousands of persons I have encountered in my career and my readings as well as the many more tens of thousands of anonymous minds who gave me my language, worked out my field of genetics, and shaped my personality.

No comments: