Death and Biological Individuals

Recent discussions have led me to become more critical of the biological concept of individual – as in an “individual organism.” What differentiates an individual organism from an individual gene, chromosome, organ, population or consortium? Why are some levels of organization favored over others?

Concepts of death vary as we consider who is talking about it (3.1) and what exactly they see as ending (3.2). In each version, it’s worth thinking about what ended and what persists. One of the reasons that biological death (as stated) seems insufficient comes from our desire to make comparisons between something before and after death.

In biological death, we might want to compare the operation of the lungs or the heart or the brain before and after, but we can’t speak of the organism after, because it has ceased to be an organism. Does it make sense to speak in the present tense of a “dead organism” or only in the past tense of an organism “that died”? The organism has activities and (in some concepts) preferences. The former organism does not.

Significantly, biologists have come to speak of organisms having interests concordant with the persistence and spread of their genes. Thus it is “in the interests” of an organism to die when it leads to the success of its offspring. This inclusive concept of fitness (or more roughly interest) has led to a language of persistence beyond death, and calls into question what we mean by “individual organism.” Many organic packets have these long-term interests, while also being discrete in time and space, capable of metabolism, subject to natural selection, and containing complex information, but don’t make the cut when we think of individuals (e.g., sperm, eggs, endospores, placentas). If they have all of these traits, I wonder what benefit we derive from not thinking of them as individual organisms. Clearly, they obey the same rules for competition, cooperation, and selection as organisms proper. Would we not be better off in biology by including them? Should we not apply population models and concepts of adaptation to them?

This broader view of biological individuals provides pragmatic help when trying to understand the evolutionary forces at work in intra-species, even intra-body competition (for example, conflicts among mother, placenta, and offspring). It also provides help when we look into inter-species cooperation (as in the case of mitochondria, thought to be organisms that became organelles).

The commitment to individual human persons – and by extension individual organisms in general – may be doing pragmatic harm within biology, even while it preserves metaphysical and pastoral interests. If this is the case, then it is worth asking exactly what those interests are, how we discern them, and whether they are worth the cost.

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