February 23rd, 2007

Vexen Crabtree 2015

Single-cell life and hormones

For some reason, it has struck me as brilliant and wonderful, the history of how single-cell organisms evolved to detect chemicals in their environment (simply using lipid-membrane spanning molecules)... and that the same mechanisms are now the same methods that multicellular organisms use to co-ordinate activities between cells.

It really struck home to me that we are (in Dawkins' words) "colonies" of cells acting together...

I can imagine each cell "thinking" it is alone in the environment, simply not knowing that actually it is busily communicating with millions of other cells' products, rather than with the environment external to the body.
The mechanism of chemical sensation that originally evolved to detect environmental substances now form the basis for chemical communication between cells and organs, using hormones and neurotransmitters.
"Neuroscience" by Bear, Connors and Paradiso, p189</p>
Anyone else find this oddly inspiring and awesome? So simple... there wasn't two different paths of evolution for cellular senses, but one... which became used in two very different circumstances!

I guess that is why some diseases which are basically single-cell sometimes react en masse or change their behaviour en masse. (We have found that sometimes a critical mass of a certain excreted chemical causes a group change in single-cell disease behaviour).

I've added some of this to "The Evolution of Life from the Primordial Soup to the Cell" by Vexen Crabtree (1999) - the page really does need to be made scientific, rather than rambling!