Life? Don’t talk to me about Life.
– Marvin the Robot
– Encyclopedia Brittanica
The javelina was dead, no doubt about it. By the looks (and odor) of the ruin which lay in the ditch, it had been several days since the animal had lived, as such.
Most likely, it had been hit on the nearby road and dragged itself to the protection of the ditch before collapsing. ‘Collapsing’ means: it ceased to respond as a javelina. Certain nerve cells lost their flow of metabolic substrate, could no longer transform energy in covalent bonds into electrical potential across cell membranes, and so could no longer respond as nerve cells.
The javelina behaved as a javelina if and only if those nerve cells behaved as nerve cells: no more nerve behaviors, no more javelina behaviors. Yet the remainder of the organism ticked along for quite a while after its defining brain functions ceased. Less sensitive tissues took minutes, or even hours to stop responding, growing, reproducing, etc.
Even after the last of the body’s eukaryotic cells ceased to do all those life-defining things, the prokaryotic components of the javelina carried on. Many of the bacteria which had worked with its other cells to keep the animal alive and healthy before it came to lie still in the ditch, continued to grow, metabolize, reproduce, etc.
At the other end of the javelina’s timeline, we see a similar situation. Before its mother could conceive, the environmental circumstances had to be right for piglets. Furthermore, its mother and father had to be right for the circumstances. They had to have a set of characteristics which led to survival and relative prosperity in their particular living conditions.
Within those proper circumstances, gamete membranes met and fused, DNA recombined, placental syncytium formed, organogenesis took place, the piglet began to exhibit its own physiology, and the little javelina emerged from the amnion to take its first breath. From some fairly basic biochemical reactions to the defining processes of biology itself, the animal faded into life, much as it faded into death.
Many people find this picture disconcerting. They yearn for the simple life, where our definitions are definitive and what’s real is real in and of itself. But that’s not what we have. The simple life, and its decadent certainty, are not available to us.