Evolutionary Ethics 2232 BACKGROUND ASSUMPTIONSThe central assumption of evolutionary ethics is that genes direct the construction
of the body and the brain, producing, maintaining, and eventually shutting down,
according to timetables for development and senescence, morphological structures,
physiological mechanisms, and behavioural features in living organisms and that
those genes that produce forms, processes and structures more conducive to their
own survival and replication than other genes tend to dominate in populations.
This insight can be expressed in terms of competition and rivalry amongst alleles
of “selfish” genes [Dawkins, 1976, 2]. An individual organism is on this view a
machine endowed with certain behavioural propensities and competencies that a
federation of genes has jointly constructed, each acting in its own interest, however
much it is constrained or assisted by its neighbours. Summarizing:
- Genes contain the instructions for building organisms that have morphology,
exhibit behaviour, and that construct species-typical artifacts. - Morphology and behaviour are shaped by selection for particular genes, some
of which are more effective replicators than their variants. - Overt competition for food, water, shelter, reproductive advantage, etc.
amongst members of a breeding community or between groups plays some
role in evolutionary change. - Sexual reproduction in a species implies the existence of two distinct geno-
types (and variants of them) and varying degrees of sexual dimorphism in
the phenotypes. In humans, the evolutionary process has resulted in some
degree of dimorphism, not only in bodily structure and physiology, but in
cerebral organization, hence in dispositions and capabilities. - The number of females in breeding community has more influence on popu-
lation dynamics than the number of males; the fertility of females constitutes
a “limiting resource” for males. - The human mode of life incorporates features such as food-sharing, mutual
assistance, tribal loyalty, partiality to kin, social dominance of some humans
by others, protracted care of the young by mothers and other females, and
some degree of paternal care.
From these theses, it is argued, one may explain certain features commonly
observed in human social systems that might surprise a rational but scientifically
uninformed visitor from another planet. Such features might include the division
of labour, hierarchical and political systems, sibling rivalry, parental repression
alternating with parental devotion, sexual jealousy, monogamy punctuated by in-
fidelity, and hostility to strangers. Humans who possessed too little by way of
the dispositions and emotions that sustain these practices failed to pass on, it is
argued, as many genes as those who possessed them.