Why is life programmed to survive?

[Arkilogue]

What about the cells that make up the protective dead layer of our skin?

And even more interesting...what about the 20% of cells that self sacrifice in slime mold stalks so that the others can launch out of the spore head?

That is a good question, isn't it.  And yet the 'sacrifice' those 20% make is really no greater than the sacrifice the cells of a multi-cellular creature make in becoming one of a kazillion bone cells or a white blood cell or any of the others including those dead skin cells on the surface of our skin which you mention.  Apparently, it doesn't work to anthropomorphize by imputing our subjective states into the actions of a single cell.  Very likely neither a bone cell nor any of the mold stalk cells feels heroic.  They lack anything we'd recognize as subjective states.  But the process of selection works as well with built in 'sacrifice' of individuals for the survival of the kind (species/family/etc) as it does for the selection of individual multi-cell creatures.  The living material survives to perpetuate its kind and that keeps the ball rolling, no celebratory subjective states necessary.

How do we know they have no subjective states? If fact what are our subjective states? Are they thoughts or feelings? Do plants have feelings and react to stimuli and learn? Yes.

http://www.pri.org/stories/2014-01-09/ne...out-plants

The new research, he says, is in a field called plant neurobiology — which is something of a misnomer, because even scientists in the field don't argue that plants have neurons or brains.

"They have analagous structures," Pollan explains. "They have ways of taking all the sensory data they gather in their everyday lives ... integrate it and then behave in an appropriate way in response. And they do this without brains, which, in a way, is what's incredible about it, because we automatically assume you need a brain to process information."

And we assume you need ears to hear. But researchers, says Pollan, have played a recording of a caterpillar munching on a leaf to plants — and the plants react. They begin to secrete defensive chemicals — even though the plant isn't really threatened, Pollan says. "It is somehow hearing what is, to it, a terrifying sound of a caterpillar munching on its leaves."