Nov 23, 2024
Nov 23, 2024
The story of life on earth began rather quickly once the planet formed at the right distance from a star (sun) to permit the presence of liquid H2O (water) because of ambient temperatures and sufficient mass and resultant gravity. The earth formed roughly 4500 million years ago, and as best as can be gleaned from fossil records, life (unicellular and prokaryotic) began between 3500 and 4000 million years ago. Thus, within a relatively short time, chemistry with the help of physical forces like lightning, led to formation of complex molecules and eventually RNA and DNA.
In societies where the ones who have usurped or misused power and abused it to oppress and deprive the bulk of the citizenry, which is generally stupid and slow to get riled, for a sufficiently long period and beyond the limits, we get revolutions or insurgencies. |
The formation of a cell and even the more primitive bacterial cell is a little more difficult to explain, but its very existence is proof of the ease of its development. These unicellular life forms were the only ones until approximately 2200 million years ago when (still unicellular) eukaryotes developed by the fusion of two different prokaryote cells. The eukaryotes had a nucleus and other bounded organelles (compartments specializing in different metabolic tasks).
The first prokaryotes were bacteria belonging to the family Archae. We see them presently in undersea thermal vents. They metabolize H2S (hydrogen sulfide - toxic to us) and are tolerant to extremely high temperatures and hydrostatic pressures. They and all other bacteria use binary fission to reproduce and thus have the technical capability of immortality. When some life forms by chance synthesized chlorophyll like substance, they were able to convert atmospheric CO2 and H2O into sugars and other nutrients and organic molecules in the presence of sunlight and release oxygen as a byproduct. This required other organisms like mitochondria to evolve to synthesize cytochrome oxidases to utilize oxygen for burning nutrients for energy. The rising oxygen levels in the atmosphere were toxic to anaerobic organisms and evolution by chance engineered the fusion of one prokaryote with a mitochondrium to form an eukaryotic animal cell, and of another prokaryote with a chloroplast to form a plant cell.
An analogy to human society is the pristine but ignorant, yet self-sufficient existence of Adam and Eve before consuming the apple of knowledge. The archae bacterial and prokaryotic phases of life were idyllic but primitive. The pair bonding of Adam and Eve is like the merger of two prokaryotes to form an eukaryote cell with division of labor, where the woman forages and the man hunts or scavenges. Of course the whole story of Adam and Eve is pure bunkum. Humans, like their ancestors the apes and monkeys before them, are social animals and have always lived in groups, since they evolved. The earlier groups were formed of extended families. They are a weak species and not the crown of the predator chain and incapable of survival singly in their original ancestral habitat. Their social history is more analogous to the evolution of multicellularity in animals.
The primitive beginnings of multicellularity can be traced as a mere tendency even in prokaryotes. Bacteria often live in clusters or chains as in staphylococci and streptococci. There is a prokaryote named Anabaena found in ponds. It consists of a chain of cells in which nine cells perform photosynthesis and every tenth cell has the unique biochemical ability and machinery to use atmospheric nitrogen and fix it by synthesizing amines and more complex nitrogen compounds. The division of labor between cells of a single multicellular life form is analogous to the development of culture and civilization in a society, which require the acquisition of unique and special skills and more importantly to co-operate for collective benefit by otherwise selfish individuals. In monkeys and apes, there is a formation of clans. In some cases the females are exogamous and leave the troop to join other clans or in others as in lions where the females stay together but the males are expelled and capture their own harem, either singly or as sibs. In humans this leads to matriarchal but more commonly patriarchal clans, castes, linguistic groups and eventually nations or ethnic group affiliations.
In primitive human societies there was little to no hierarchical stratification based on status or even gender despite some division of labor and some specialization, but as societies became more complex as in Mesopotamia and Egypt around 3500 BCE or as recorded history can access, we see the beginnings of distinct classes in society with more or less weighted status and even the beginnings of slavery. It was agriculture which first provided the surpluses, which allowed larger groups to live together, be able to afford the luxury of spare time to learn new skills and specialities, indulge their curiosities and use the unique human ability of language to communicate and pass on information, knowledge and skills to innovate and learn. The accumulated surpluses of grains or goods served as a temptation to other groups to wage war to capture the fruits of someone else’s labor and skill. This led to slavery as a custom, to benefit without work and as the easy and preferred way out of the constraints of contemporary technology to improve living standards and gratify sexual and other desires.
Multicellularity in evolution begins as a transient occurrence in slime molds. Each amoeba lives as an individual in times of plenty. Dwindling food resources cause one to emit a distress call. This shows that one of the earliest requirements for multicellularity is communication. It means that not only a signal or distress call must be emitted but also relevant individual cells must have the ability to receive and interpret the call. Evolution as others and I have repeatedly emphasized in my writings uses what is already available. It falls back on adenine and guanine, the two purines which together with the two pyramidines are the key building blocks of DNA. The enzyme adenyl cyclase converts the primary energy molecule ATP to cyclic AMP which serves as a messenger both within and between cells. The GTP and GDP knife edge seesaw, mostly serves intracellular messaging. This signal brings other amoeba together, to form a slug and each cell takes different functions. The slug travels, finds suitable environment and some of the cells sacrifice themselves to become a stalk, while others spread as spores to start their life cycle again as unicellular individuals.
Only some cells get the privilege of reproduction. In true multicellular organisms all the cells have identical genes so it is more acceptable for some to sacrifice without the fear of Nirvana or extinction. Such utopian selflessness banking on self regulation is too hazardous as the sub-prime crisis should have taught us. Evolution therefore has a very strict, zealous and vigilant regulator called the immune system (unlike the SEC, FASB, Federal Reserve etc.) and in addition, the neighboring cells of any given organ like a neighborhood watch committee, police each organ by judging the crowding and emitting local inhibitory signal warnings to any potential renegade cell. It is this which prevents an uncontrolled selfishly proliferating cell which we call cancer from destroying the multicellular organism. On rare occasions, the regulatory immune system goes into overdrive and attacks healthy normal cells to cause autoimmune diseases, which in society we deem to be like the abrogation of citizens’ Bill of Rights and the Constitution by a misnamed Patriot Act.
In societies where the ones who have usurped or misused power and abused it to oppress and deprive the bulk of the citizenry, which is generally stupid and slow to get riled, for a sufficiently long period and beyond the limits, we get revolutions or insurgencies. When as in the 1640s in Britain, Charles the First, pushed the people and parliament and in France of 1789, Louis and the nobles oppressed and exploited the public too much, revolution occurred and they were beheaded. Similar problems occurred in Russia in the teens of nineteen hundred, China in the 1940s and Iran in 1979 and are now happening in Tunisia, Egypt, Libya and Bahrain. If the oppression is by foreigners occupying forces, it results in the suicide bombing of the slime mold stalk for the benefit of the release of spores as Professor Robert Pape’s research on suicide terrorism proves.
The prime reason for the development of social safety nets in developed countries was the fear of the revolution of the have-nots endangering the life and the lifestyle of the haves. That is why the Roman Emperors used their treasury to provide free bread and circuses to the proletariat. That is why Kuwait forgave the debts of all its citizens and Saudi Arabia sanctioned 130 billion dollars of largesse for its citizens. The problem in America is that the mad Republican oligarchy has not only captured power but also the regulators by the connivance of the supine Democrats and the self centered spineless president. That is why we hear cant from cantors who want to deny unemployment benefits and disaster relief to the jobless and the hurricane and flood victims, unless there are matching budget cuts. That is why in Republican debates we have the psychopathic contenders and the cheering Tea Partiers, now advocating their newest motto of “Free To Die” as Paul Krugman labels it for those without health insurance, as a continuation of Milton Friedman’s “Free To Choose”. Naomi Klein calls it “The Shock Doctrine”, the Pentagon calls it “Shock And Awe”, they say tomaato, we say tomayto, some chant Obama, others Osama, what’s in a name, they are all the same.
18-Sep-2011
More by : Gaurang Bhatt, MD
Dear Bill, I remember our brief posted conversation when we agreed to disagree about the tea party. You being raised in Gujarat, have a stronger claim on me. I have read parts of Eiseley's book "Darwin's Century", but not the one you mention. Therefore I looked up the book on the internet and read what was available from the first chapter. He has a story of the history of life which meanders somewhat differently, but to paraphrase another ancient --"There are many rooms in my father's mansion" and he could have added many roads to reach it too. No one can be certain, but Eiseley's view of a general purpose, but specially evolved brain has been currently replaced by a modular brain with special components, which generally evolved in response to internecine rivalry. As grudgingly acknowledged, it is the competition amongst the smartest incoming classes at our premier Ivy league institutions which contributes more to the great outcome, rather than the distinguished professors, many of whom are poor teachers or not interested in teaching. The reverse is our problem with schools, where we foster self esteem more than education. I am just an avid reader, bored by golf, with the enthusiasm of a kindergartener playing show and tell. Cosmides, Tooby & Barkow have written a lot about the brain and evolutionary psychology and Gazzaniga has a series of books on the brain and social issues, which you may enjoy reading with your interest in evolution and social controversies and dilemmas.Richard Dawkins has a series of books on evolution which are fun and good. There are unresolved and very very difficult problems about the origins of a cell, which theologian Paley would have loved to use. Nobel Prize winning Christian Duve's book, "Vital Dust" is very good.Inner Fish by Neil Shubin, Endless Forms Most Beautiful by Sean B. Carroll and The Plausibility Of Life by Kirschner & Gerhart are the creme de la creme in the last five years in evolutionary development, the newest science. Lewis Thomas wrote in a fashion similar to Eiseley but less flowery and fewer books. I will be happy to hear any specific comments, criticism of the version of others, which I merely wrote about, or elaboration of Eiseley's version or your views thereof. Shanti, bhai--gaurang |
Believe I have read others of your erudite articles. Enjoyed the sort of deterministic evolution of life sequence...makes it sound so very probable and easy. Have you perchance read Loren Eiseley's "The Pyramid". He has a slightly different take and was a world class scientist (paleontologist) and humanistic writer. Regards, Bill K. |