Enhanced Complexity in Eukarya
by MikeGeneIt is well known that eukaryotic cells are more complex than prokaryotic cells. For example, while the typical eukaryotic cell is 10-100 micrometers in diameter, contains numerous membranous organelles, has a cytoskeleton, and reproduces through mitosis, the typical bacterial cell is only 0.2-2.0 micrometers in diameter, lacking organelles and cytoskeleton, while reproducing through binary fission.
Yet the theme of enhanced complexity repeats itself at increasingly smaller scales like a fractal image.
January 27th, 2007 at 9:37 am
A good blog entry. I was going to attempt to answer your question but will defer to your future blogs.
Comment by Bradford — January 27, 2007 @ 9:37 am
January 28th, 2007 at 10:43 am
Bradford,
Feel free to opine. I don't have THE answer in mind, as these are truly open-ended questions. But I will work my way toward one potential factor.
Comment by MikeGene — January 28, 2007 @ 10:43 am
January 28th, 2007 at 1:08 pm
Hi Mike,
I have done some pondering about the eukaryote thing. Here are a couple of musings that I have had.
1 - As the difference between the eukaryotes and the prokaryotes is so significant, if the eukaryotes evolved from the prokaryotes via natural processes one would surely expect that there would be some organisms that are part way between the two. I assume there are not. If all of the necessary intermediates happened between these two domains, one would surely think that one or two (or twenty) would have found niches and settled in.
2 - It is my amateur understanding that ALL multi-cellular organisms are eukaryotes. If this is correct, it would be reasonable to assume that there are factors in the eukaryote that permit multi-cellularity. This has the strong appearance of foresight — front-loading.
Comment by bFast — January 28, 2007 @ 1:08 pm
January 28th, 2007 at 1:29 pm
2 - It is my amateur understanding that ALL multi-cellular organisms are eukaryotes. If this is correct, it would be reasonable to assume that there are factors in the eukaryote that permit multi-cellularity. This has the strong appearance of foresight "” front-loading.
If I were going to fashion a front loading hypothesis it would center around cellular differentiation and front loaded yeast. Stem cells have the potential to go in many different directions. Be prepared is their unofficial motto. Although the enhanced complexity is obvious, associating it with more complex fitness needs was something I have assumed without thinking much about it. Simplicity might allow for enhanced rapid response options benefiting the affected species.
Comment by Bradford — January 28, 2007 @ 1:29 pm
January 30th, 2007 at 2:34 pm
"Why is the eukaryotic cell plan so much more complex than the bacterial cell plan? What does this increased complexity tell us about the eukaryotic cell plan relative to the bacterial version? Why does the theme of enhanced complexity reach into every aspect of the cell plan?"
It's all according to the Law of Requisite Variety.
Comment by Rock — January 30, 2007 @ 2:34 pm
February 2nd, 2007 at 5:31 am
Hi bFast,
Sorry for the late reply.
I think this is a valid point.
Bacteria often exist in a multi-cellular state. They form colonies and biofilms all the time. They coordinate with things like quorum sensing. It's actually a certain type of multi-cellular existence that is intriguing. There are, after all, no prokaryotic trees or mice.
Comment by MikeGene — February 2, 2007 @ 5:31 am