A living organism contains every component of its entire evolutionary history. We comprise 99.9% ancient - archaic - primordial stuff. Animals, plants, bacteria, viruses and archaea are living histories of all they / we have ever been since life’s origin and long before as molecules in the primeval stew. It is not simply that every human cell once had the potential to be any organ or tissue but it has the potential to be any creature that ever was since the beginning of life on Earth. Send our little “human’ blastomere an instruction to become a Devonian fish and voila! Mom gives birth to a coelacanth.
The spectacle of stem cells receiving instructions to develop into neurons, epithelium, nephrons, cardiac tissue, lungs, bones, blood, hormones -
You - do this
You - do that
Not now! - wait 10 seconds until x,y,z is complete then it is your turn
A cellular headquarters at blastomere like a busy general writing orders to 1,000 colonels
Gentlemen - Start your kidneys !
The kidney begins in deep time 400 million years ago give or take 100 million years. The kidney begins to grow in each new life of mammals, birds and reptiles. The human kidney recapitulates this early form in our fetal growth sequence. For the first three weeks a human has the kidney of a 400 million year old hagfish. It disappears after a few weeks replaced by a second version that became extinct 100 million years ago. This second kidney actually functions in the human fetus as a filter for a few weeks. At week fifteen our final form kidney emerges to serve its filtering, blood pressure regulation, secretion, excretion services throughout a life.
There are many who disparage Darwinian evolution-natural selection using examples of specific animal features such as eye parts, kidney-heart system to make their case against. Their question is some form of “How could these systems function at 10% eyeball or 20% kidney? They fail to acknowledge 99% of evolution occurs at the quantum-atomic-cell nucleus level i.e. not apparent to cursory examination of obvious animal features or the fossil record. the vast ocean of process that drives any phenotypic expression ( i.e. a part or process you can see) is not readily apparent. The stuff we can see: feathers, fins, limbs, organ systems, metabolic processes are the residue of much finer process not the heart of the matter, not the essence, the guts of evolution-mutation-selection. Evolution is not only not at the level of the individual life as Darwin asserted it isn’t at the gene level as Dawkins proposed 39 years ago in his iconic book "The Selfish Gene".
Organisms evolve within themselves throughout a single life via intra-signaling: limb to nucleic material, organ to nucleic material. Intra-lifespan epigenetic activity across 50 cell generations or 500 or 5,000 cell generations prior to registration as a change in DNA base pair number or sequence i.e. traditional sense of a mutation and subsequent transfer to a new generation of germ cells. Thousands, tens of thousands of mutations accrue within tissue cells before a gene is modified. Nature is more carefully conservative than we have assumed. there is a dialogue that occurs throughout the life of an individual - messages for improvement of a process or the coordination of an organ component with other organ systems. These post-translational signals are registered in histones-junk DNA and when a threshold is reached, a message is formally encoded into DNA for conservation. The histone acts as capacitor storing a charge for change and then relaying a signal to DNA molecule at germ cells. What is the pathway from organ cell to germ cell? Perhaps “junk” DNA is stored information that has yet to reach the point where it signals a change in protein production - regulation.
The old model of a nucleotide getting zapped by a UV ray, mutating and causing a new expression to be tested in the following generation(s) for fitness-survival is grossly over-simplified. During the span of a single lifetime there are 10 million or a billion mutations, tryouts, experiments in every organ in every metabolic process, in every cell in the body. It is the sum of these multitudes of mutations that we see as an improved blood pump. Organ and metabolic systems within a single body during a single lifespan communicate myriad small changes that become encoded in DNA. The following is a partial list of cell types and their lifespan in a human body:
- Heart muscle cells 40 million replaced each year of 4 billion total
- Epithelium-small intestine 2-4 days average lifespan of cell
- Stomach 2-9 days
- White blood cells 2-5 days
- Platelets 10 days
- Sperm 60 days
- neurons lifetime
- bone cells 10% per year
- eye-lens lifetime
- female gametes ( eggs) lifetime
- Red blood cells 100 million new ones per minute of 9 trillion
Look at Darwinian evolutionary process re: fecundity-mutation-natural selection within a single body not where a base pair mutates, expresses a longer claw-dominant bear-wins mating battle, makes more offspring with longer claws and over a million years all bears have longer claws. the viability of the longer claw gets resolved 10,000 times at the cell level. It must make sense here as an advantage for 1,000 generations before this mutation gets transferred into the DNA as either an expressed or a conserved trait.
TOE (Theory Of Evolution) skeptics ask how an entire system like the kidney could evolve as a result of the accepted model of mutation-natural selection. How does an animal use 10% of a kidney even if a simple archaic pronephric model as seen today in the hagfish (and surprisingly, in early fetus of humans, though non-functioning and dissolved after three weeks). How or why does one have only one half of a filter even if it is a primitive one? There are structures other than kidneys or proto-kidneys that perform a filtering function - every cell membrane is a filter. It is a kidney in a sense if it keeps some things in and others out. It is easy to visualize an ancient kidney - a ten percent kidney working in concert with fifteen percent blood and a twenty percent heart. Every cell with a membrane is at least a ten percent kidney by definition. There was a point in time where where a few cells combined to accelerate this filtering process i.e. the cell membrane handles X and Y and the incipient kidney handles Z.
Many TOE critics whether knowledgeable Creationists, educated, rational science-trained sceptics lack imagination. There ought to be a branch of bio-science “Incipient Organ Systems” that explores archaic organ interaction, patterns scalable into greater complexity like a landscape painting transitioning from foggy late Turner into precisely rendered Frederic Edwin Church.
The time is two billion years BCE. there are twenty multicell organisms at the starting gate. The primordial ooze has become toxic. Who will survive? Gentlemen start your kidneys !*
August 29, 2015 2:36 pm