Ayala on the uniqueness of humankind & on biology & ethics ~ page 1 Ayala on the uniqueness of humankind & on the relationship between biology & ethics

Ayala on the uniqueness of humankind & on biology & ethics ~ page 1

Ayala on the uniqueness of humankind &

on the relationship between biology & ethics

Francisco Ayala. “Human Nature: One Evolutionist’s View.” Whatever Happened to the Soul? Eds. Warren Brown, Nancey Murphy, & H. Newton Malony. Minneapolis: Fortress, 1998.

The specialness of humankind has biblical roots (Genesis 1:27).

Yet humans emerged in the evolutionary process from other animals. Hominids emerged from chimpanzees 5 - 7 mya Homo erectus - 1.8 mya




Homo neanderthalensis appeared in Europe ca. 200,000 tya ago and persisted until 30-40,000 tya.

Debate over the origin of modern humans

Multiregional hypopthesisAfrican replacement model




So what is distinctive about humans?

Anatomical traits • Bipedal gate & erect posture (we are

only vertibrate species with these characteristics) (36).

• Relative to body mass, humans have largest & most complex brain & reorganization of brain (cerebral cortex is much large than in other primates)




• Opposing thumbs & arm and hand changes

• Reduction of jaws & remodeling of face • Changes in skin & skin glands • Reduction in body hair • Cryptic ovulation & extended female

sexual receptivity • Slow development • Modification of vocal tract & larynx




Distinctive human behavioral traits • Subtle expression of emotions • Intelligence: abstract thinking,

categorizing, & reasoning • Symbolic & creative language • Self-awareness & death-awareness • Tool-making & technology • Science, literature & art • Ethics & religion




• Social organization & cooperation (division of labor)

• Legal codes & political institutions Biological & cultural evolution

• Are two kinds of inheritance Biological -- endosomatic Cultural -- exosomatic; makes

possible the cumulative transmission of experience & knowledge from generation to generation




• Cultural inheritance makes possible cultural evolution

Cultural inheritance includes a new modes of adaptation -- adaptation by changing the environment to suit the needs of our genes (39)

This adaptation, compared to biological, is much more rapid & can be directed




Biology & ethics Evolution selected for human intelligence, not

for ethics & ethical behavior Human intelligence, in turn, has the capacity

for ethics & ethical behavior Thus the capacity for ethics is biologically

determined, is part of human nature




But specific ethical norms are the product of cultural evolution

Ethical theories based on evolution tend to commit the naturalistic fallacy -- Herbert Spencer, E.O. Wilson




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Ayala on the uniqueness of humankind & on biology & ethics ~ page 1 Ayala on the uniqueness of humankind & on the relationship between biology & ethics