Genes, genome and apoptosis
June 01, 2002 Dov in biologicalEvolution, and copy to SA.
The challenges of making sense of genome structure when chromosome size and number vary widely between closely related organisms are highlighted in these news features:
http://www.nature.com/nlink/v417/n6887/full/417374a_fs.html
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v417/n6887/full/417374a_fs.html
I do not tire and I am not exasperated in my effort to convince open minded persons that all challenges of making sense of genome structures, even facing widely varying chromosome sizes and number within closely related organisms, are explainable when you adjust your concept of Life. Again and again ad nausia. It is not the Cell that is the base unit of life; the Cell is but the structural shell that houses the Genes, which ARE the base units of Life and existed at a pre-cellular era. The individual Genes have (and still do) evolved and speciated and associated and competed and strove to survive and replicate in the same way as mono- and poly-cell organisms evolved and speciated, Life being a fractal phenomenon. We do not yet know the Origin of Life earlier than the archaic gene era. This is not different from not yet knowing the nature of the pre big banged universe.
———————
June 02, 2002
From SA to Dov:
Dov, I agree that this is not chromosomes and cells that evolve but genes. As a matter of fact, many share this point of view. Now, here is real challenge for you. Explain apoptosis from the prospective of your theory of "living nucleotides." I would love to hear what you have to say about this.
———————-
June 03, 2002
From Dov to SA:
SA, not having any informed background on apoptosis I searched for what is known about its genetic origin, to learn how far back in evolution it is observed.
In a very brief search it appears that the origin of apoptosis is traceable not only in eukaryotes but also, in a "pre-apoptosis" version/form, in prokaryotes.
Thus PCD/and-its-prevention seem to be an early evolutionary development by cells and also by nucleated genomes for either attack/destroy competing/threatening cell, or/and for survival of a genome-bearing community by eliminating "unacceptable", threatening mutations.
With evolution of poly-celled organisms its original role has taken (and also invoked) many new turns and functions and modes of actions, as expected in a course of Evolution…and especially in a course of ever more complicated/intricate levels of Life's fractal phenomena.
——————-
June 03, 2002
From SA to Dov:
Dov, Apoptosis is a miraculous thing. An apoptotic cell remind me of a samurai who never thinks twice before killing himself. There is a difference between suicidal samurai and apoptosis, though. Samurai's death comes because of his sick ideology. Apoptosis comes as an act of altruism. Apoptosis teaches us that altruism is not intrinsic to higher forms of life, like mammals, birds, crocodiles, etc. It is an essential property of cells, or (in your term) of spaceships full of genes. Apoptosis is an active process. Apoptotic cell is not just dying because of the lack of food or oxygen. There are genes inside it, such crews, that run around destroying the spaceship and other teammates (apoptosis includes chopping DNA in pieces).
Apoptosis is our natural protection from cancer - cancerous cells normally appear in our bodies right and left, but they kill themselves actively. Apoptosis is our protection from autoimmunity - if an immune cell suddenly attacks other cells of its own body, it immediately realizes its own mistake and kills itself. Apoptosis is a way of body development - you probably know that embryo's palms are just little disks at first, and then fingers appear because some cells die in between, making separate fingers. Apoptosis, or suicidal death, is a way of life on this planet, at the molecular level. Thus, life is full of not only competition, but also altruism, at a very basic level.
Now, some gene crews are not as altruistic. They refuse to sacrifice themselves for the sake of other adjacent space stations. Then people get cancer, or autoimmune disorders, or developmental anomalies.
I thought this supports you hypothesis.
SA
————————-
June 04, 2002
From Dov to SA:
SA, I promised "no more", but your message invites a comment:
In my opinion you anthropomorphize apoptosis. Altruism, as well as every other human abstract idea or concept, is just one of our tools, a cultural tool, used by humans ( maybe by other terms by other poly-cell organisms ) in the biological drive for genome replication.
Dov