(no subject)

[dreamer_easy]

*Spooky Lost in Space narrator voice* AS YOU REMEMBER, I want to find out why eukaryote cells (cells with nuclei, like the ones in mushrooms, daffodils, and me) have repeatedly evolved the ability to form tissues - that is, different cell types working together - and prokaryotes (cells without nuclei, like bacteria) never have. This was mentioned in passing in some book I was reading but I still don't have the answer. Anywho, what has emerged from my various nose-to-page encounters is that prokaryotes in fact do something jolly similar. Richard Fortey in Life: An Unauthorised Biography describes microbial mats, large colonies of different unicellular species living symbiotically. I've just come across an article in a recent New Scientist which describes biofilms - colonies of bacteria, glued together with polysaccharides, and communicating amongst themselves with chemical signals. Neither of these are exactly the same as eukaryote tissues, but they're similar in a lot of ways; obviously cooperation as a strategy had been around for a long time before the arrival of the nucleus, and eukaryotes just worked out how to exploit it in a new and spectacular way, ie by building bodies.