Our genetic history

Our genetic history

We all know that we have cells, and inside of these cells there is a nucleus. What we are less familiar with is that the cytoplasm around the nucleus contains a network of mitochondria organelles. They produce energy, process and carry oxygen, send out signals for cellular destruction, process sugars and other chemicals, send signals of defense to the immune system, and carry our genetic history — the story of our migration and evolution.

Mitochondrial DNA

Inside each of these little mitochondria tubes is a matrix with its own 37 gene, circular strand of DNA that we inherit in duplication of our maternal line. Over the generations there are occasional mutations that occur. The geographic setting, environmental chemical balance, lifestyle changes, and even occasional sperm tails entering into a fertilizing egg, can mutate mitochondrial genes. Investigations into the D-loop (which is a small area of the circular DNA strand) have proven to show correlation between these mutations and to hereditary health problems, such as diabetes, deafness, cardiomyopathy, Leber’s optic neuropathy, and more. mtDNA also carries non-hereditary gene mutations; many cancers have been linked to these through environmental changes.

The DNA is useful in research for disease prevention and treatment because it has proven to be related to so many of our health research topics. For example, the fact that these mitochondria produce complex proteins that boost immune system functioning, and that we can isolate these proteins, could lead to headway in aids research.

mtDNA literally carries the keys to our existence as its research and application potential umbrellas over our current health concerns. It also unlocks the questions that we have about our origins.

Haplogroups

Over time, the hereditary mutations of mtDNA are categorized into haplogroups. These groups track the rare mutations through an ancient time line, with the surviving mtDNA extractions of the oldest human, and pre human remains. There is a direct map of the migration and origin of your specific haplogroup for two distinct reasons. In the first place, because the mtDNA is duplicated in genetics, and passed down through the maternal line, it is easy to trace your relationship to our ancient past. In the second place, mtDNA is present in the network of hundreds to thousands of organelles in the cytoplasm of every cell, so extraction from old remains is much more effective than the DNA found in the nucleus.

There are genealogical test sites, that range in the $200-$500 price, where you can find out what your haplogroup is. This can give you detailed information about mutations that may affect your health, and a direct path of the migration of your ancestors. If, however, you know that your mother’s mother’s mother was of a certain background, in a certain place, there is enough information about general migration that will fascinate you. Investigating the known haplogroup of that relative’s location and heritage will help you trace the past.

Haplogroups are measured against the earliest known Female, originating in Africa, between 1 and 2 million years ago. For genealogical simplification, she is known as Mitochondrial Eve. From there, mutations form new sequences, and are labeled with letters. Eve is L, L has several subgroups, such as L1, L2, etc. Then, the next tier is labeled M and so on… these Haplogroups are then tracked in their migration around the globe.

Genealogical Legacy

This information fuels doubt in the common patriarchal traditions of family hierarchy. Boys are valued more in many countries, because they can labour in some areas — but in all areas, because they carry a name; they leave a legacy. In China, the one child catastrophe threw millions of young girls into sexual slavery because boys were the way to carry your family into the future. I suppose it’s a little too late to tell them that a name only traces back so far, a thousand years maybe, if you are lucky — and by sending your daughter into slavery, you have thrown your genetic heritage into the lowest possible class.

The entire evolution of mtDNA shows that it was once a prokaryote — which is an organism that lacks a membrane and nucleus — and that our cells, which surround them, at some point in earliest evolution, engulfed the mitochondria and over time a symbiotic relationship developed. There is still debate around the details, but the idea here is that the cells that form our bodies may have become our bodies after having once been bacteria.

Implications

Will our attitudes begin to change the more we learn about this fascinating gift of the female womb? Will women be recognized for their ability to tell the truth about history, long after they have passed? Will the recognition of indigenous heritage be looking at incorporating some Métis into their full status because they carry identical mtDNA to their full blood ancestors? Will the entire evolution of mtDNA challenge the basic creation stories of religions all around the world by tracing Eve to an origin of common bacteria?

Progress in understanding

I’m surprised to see that whenever I mention mtDNA, brows bend and twitch. No one seems to know what it is, not even some nurses that are studying medicine. Unless you’re directly related to genealogical industries or cellular research, it has probably not come up, or perhaps you saw it on the corner of that ancestry page you looked up that time. Well, it seems there is much more under the surface, and we are only now starting to really dig into the significance of the staple part of our functioning. The more that I read about mtDNA, the more I realize that it is connected to everything about human body, and even human nature.

Networks of mitochondria operate together inside of a cell through the process of quorum sensing. This is a decision making process that coordinates behaviour within a decentralized group. Perhaps we could learn something from our interdependently functioning mitochondria, about our history, about our scientific future, and about ourselves.