Embryology
The great unfolding
I'm very much a layman when it comes to embryology but everytime I encounter it I'm amazed.
Before we found that DNA (chemical) was at the core of life embryology was mostly a set of observations.Aristotle studied the embryology of chickens by opening eggs that were older and older to see what was inside. He saw a blob that slowly morphed into a chick.
I observed the same thing when I was a kid catching tadpoles in the spring and watching the little thing swimming around morph into a little frog.
Then I had no concept of DNA or life as a chemical process. I also had no idea that repeated transformations on a seed can have profound implications in itself.
If we start with a fertilized egg it does what cells do - it divides into 2 cells and those divide to 4 cells and so on. After a few cycles of that genetic switches kick in so that one group of cells becomes 'left' and another becomes 'up' and another becomes 'down'. The normal process of splitting continues but now the cells in each zone develop in slightly different ways. This process continues until the community of cells becomes some sort of baby, a replicant of the parent.
That process of splitting cells continues in the baby but now is more focussed on growth than on development. Instead of a finger subdividing into more fingers fingers get bigger. And each cell develops in a way determined by its relative position in the finger.
As an aside: Paleontologists use that property to deduce the properties of nearby bones to a fossil sample because they know rules that determine bone development in a skeleton. This was long before they knew about DNA.
I once thought of embryology as a kind of unfolding. I now think of it as a process of transformation - ie - this becomes that according to the rules of a transformation. The key here is that what is 'this' depends on a selection process.
For a long time I've been working with a process that produces a kind of symmetrical picture I call a snowflake. I take a 2d image and then perform a series of transformations on it using the GIMP (free image editing software) - first I make the image symmetrical on both x and y axes and then I take out triangular sections that get get repeated and rotated till they fill the circle.
IIn fact you can do that for as many repetitions as you want but I found that doing many repetitions of the process just tends to present a grey picture full of the same ol same ol. Lately I started pushing that repetition process out to many levels because I was bored one day.
I found, as I expected, that I got more and more intricate images with each iteration. I saw that after many iterations of that process the seed that started growing was invisible but that the geometric implications of the seed were very apparent.
It struck me that embryology - the development of a baby from an egg is a lot like that. DNA in an egg is the starting point that is invisible when you see a baby. But it's influence is seen every place you look.
What do you think|?
I present regular philosophy discussions in a virtual reality called Second Life.
I set a topic and people come as avatars and sit around a virtual table to discuss it.
Each week I write a short essay to set the topic.
I show a selection of them here.