Dry Tropics Biodiversity Group Inc.
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Genetics:The basic instructions of all life are very similar. (mostly based upon "Cracking the Code"; Suzuki, D; Levine, J; 1994) | evolutionary time scale and summary |
The most alien environment imaginable would get close to an oxygen free environment, in boiling volcanic mud at the bottom of very deep sea . The bacteria that grow here, that eat sulphur, contain stretches of DNA that strongly resemble human genes!!!
The inescapable conclusion is that we last shared common ancestry with the sulphur eating bacteria more than 3.5 billion years ago. To evolve with such intricate similarity without common ancestry is just so totally improbable, that it seems impossible. Another way of looking at this … we were all formed from the same "spare parts toolkit".
Many other organisms have been studied and there is a common thread. The degree with which the basic instructions of all life, from the most humble life-forms right through to the most complex, are so similar continually astounds molecular biologists.
The entire biosphere from the volcanic bacteria, to yeasts, to plants, to humans, is all driven by the same basic engine-room. Unitary molecular intelligence.
It is apparent that life's information storage system only appeared once. We are all descendants of each other. The line of decent is unbroken.
If there was one basic toolkit set down when all this began; evolution has used bits and pieces from this toolkit to build all the different creatures.
Much of life's software, regardless of the organism it comes from, will run on the hardware of nearly every other living cell.
So far only the simple organisms like bacteria and viruses have helped provide information on the software. But remarkably the knowledge is often transferable.
Bacteria and viruses have evolved by crossing between the species software and hardware, to invade and trick the host's mechanisms. Viruses speak our genetic language, and can infect and subvert our molecular machinery to our peril.
Especially bacteria have been exposed to viruses for the longest time, and have evolved mechanisms that are good to study.
Because many plants can be cloned from any single cell, genetic manipulation is often a lot easier for plants than for animals.
Ethical and Philosophical questions
The power of genes has enormous practical and philosophical significance.
Genetic superiority was one factor at the heart of Nazi philosophy. Genetic arguments can be distorted to serve immoral objectives.
Genetically different races of humans differ genetically by 6% of the human DNA variation, whereas the variation between individuals within one race exhibit 85% of the DNA variation. I.E. your spouse's genome is quite likely more different (compared to your own) than that of a Kalahari bushman.
The present limited power of gene therapy will exponentially become more powerful. This power can be misused.
One philosophical irony - Western Culture teaches that we are distinct from the rest of the living world, divinely granted dominion to conquer, tame and control nature.
Our science is reductionist - dismantling complex systems into smaller parts then searching for rules that govern these isolated parts, that then can predict the behaviour of the whole.
Many other cultures view humans as but one member of a community of all living things, governed by an omnipresent power.
The laws of nature conceived within such world views are often holistic; - based on observations of interacting components, rather than on supposition of what those components might do if isolated from the whole.
Common to most such styles of thinking is the attitude that humans must recognise and respect the ties that bind us to the mortal and spiritual dimension of the living things.
Yet Western science has found stretches of DNA that not only relates us to animals like kangaroos and dingos - that indigenous traditions recognise as brother and sister - but to all plants, bacteria and yeasts as well.
Physical proof of our common biological heritage that unites us all under the same basic laws of life.
Based totally on other references, text mostly by Doug Silke
mostly based upon "Cracking the Code"; Suzuki, D; Levine, J; 1994
Pathophysiology; McCance, Katheryn; Huether, Sue E;1990; CV Mosby Company, Missouri.