I had this image the other day:
Consider the formation of the solar system as we presently understand it. Visualize the swirling cloud of dust and cosmic debris, with eddies coalescing into planets, moons, etc., each in their mathematically-determined orbits.
Now visualize the development of an ovary, with ova forming in their respective chambers. And overlay these concepts, and imagine stellar systems as cosmic ovaries, with planets and moons as eggs waiting to be fertilized...
Unlike sperm, which are formed continually by the millions, and have short lifespans, ova are formed early on, and only a finite number are ever created, to be released periodically through a woman's fertile life. The ova with its genetic material waits patiently during all that time--perhaps decades--for that union with a sperm before beginning the explosive process of division and multiplication of embryological development.
Once fertilization occurs, the process of differentiation and development as a multicellular organism proceeds rapidly, forming all the various tissues, organs, systems, etc. of the body within a few months. The last components to form are the ova for the next generation...
Prokaryotic cells seem to have appeared on the Earth as soon as things cooled down enough to allow liquid water to exist (at least 3.5 billion years ago). And for over 2 billion years, that was the status of life on Earth. Eukaryotic cells (into which various prokaryotes were assimilated--such as mitochondria and chloroplasts) seem to have appeared about 1.4 billion years ago. Despite an enormous amount of research into "The Origins of Life," no one seems to have figured out just how these came into being--or been able to duplicate the process in the laboratory.
"Eukaryotic cells are a prerequisite for multicellular complexity, if only because sexual reproduction required paired chromosomes, and only sex can supply the variation that natural selection needs as raw material for further study. "But multicellular animals did not arise soon after the origin of eukaryotic cells; they first appeared just before the Cambrian explosion some 570 million years ago. Hence, a good deal more than half the history of life is a story of prokaryotic cells alone, and only the last one-sixth of life's time on earth has included multicellular animals." (Steven Jay Gould, Wonderful Life, 1989, W.W. Norton & Co., pp. 309-10)
I think there is a significant analogy here between the microcosm and the macrocosm, which I have not previously seen noted, and which, I believe, offers an explanation of why the development of life on Earth proceeded in this manner--with billions of years seemingly stuck in a succession of two unicellular "holding patterns" before suddenly "exploding" (as they say) into multicellular complexity:
For those first 3 billion years, the Earth was an unfertilized ovum--rich with its own genetic material, but awaiting (as Hesiod's "Theogony" says) "the arrows of Eros"--the "sperm" in the form of comets carrying another genetic component formed not on planetary bodies, but in clouds of cosmic dust... (see www.panspermia.org for current data on this topic...).
The point at which that fertilization occurred is at the boundary between the Pre-Cambrian and the Cambrian, initiating what we call "The Cambrian Explosion" 570 million years ago. (Interestingly, there seems to have been a previous occurrence of fertilization maybe 100 million years earlier, named for the most famous outcrop at Ediacara in Australia; but this Ediacarian "proto-embryo" was apparently "aborted," leaving no descendant issue. Perhaps the Cambrian "embryo" simply absorbed or devoured the Ediacarian one--as often happens in the womb, where polar bodies, etc. form from an ovum, but never develop into full embryos.
Anyway, this is where my mind is going with all this. The Homeobox genes provide a key component of this concept, as they indicate that a basic genetic template or blueprint for the future development of all living organisms has been here from the beginning of the Cambrian Explosion.
I am getting a strong sense that this is part of the DNA carried in by those cometary "sperm" whose fertilization of the "Gaian Egg" initiated the planetary embryology that we call evolution--just as the blueprint for our individual development into a human being (as opposed to, say, a lobster) is carried in the DNA of the ovum and sperm of our parents whose union creates the zygote from which we begin our several-month differentiation into a complex multicellular organism out of an ovum which has been unicellular for perhaps decades.
I'd love to hear your thoughts on all this... And I need to do a good deal more research on the entire development (and all the stages thereof) of ovaries and ova PRIOR to fertilization--as well as "peripheral" aspects of embryology, such as polar bodies, etc. Do have any stuff along those lines you can turn me onto? I'd love to form a little "research team" of folks who know more about various aspects of all this than I do, and would be willing to help bring it all together... Do you know anyone you could recommend who might be interested?
Also, I'm looking for some good high-resolution color photos of HUMAN ova, sperm, fertilization, formation of ova in ovaries (so far, most of what I have is of fruit flies and nematodes). I want to try and photo-shop morph some of those images with paintings and photos of the formation of the solar system and the early Earth, comets, etc...