the death within

[marsden_online]

Bioblog at Sciblog talks about how death is a part of us from the very beginning

But the fine sculpting of the embryo doesn’t result solely from cell division & growth. It’s also dependent on programmed cell death, or apoptosis. This is perhaps most obvious in the development of fingers & toes, which appear as separate digits because cells lying in the regions between those future digits self-destruct (I’ve sometimes seen apoptosis described as cellular suicide).

... and possibly has been from the very beginning.

But just when did death enter the picture? Do single-celled organisms ‘die’ in the same way? After all, they reproduce largely by binary fission, with the occasional bit of unicellular hanky-panky, so the cell line surely goes on. And on…
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It turns out that researchers studying phytoplankton die-offs have found that algal and cyanobacterial cells grown in the lab die in exactly the same way as cells of more complex creatures ... This suggests that the origins of cell death go a very long way back indeed ...
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Because plankton reproduce by binary fission they are essentially clones of the parent cells & thus the members of a given species would share most of their genes with each other. If, in the face of a virulent virus, enough cells die off to slow the rate of infection, then maybe a tendency for self-destruction would actually be selected for.