1. Ayala on the uniqueness of humankind & on biology & ethics ~ page 1 Ayala on the uniqueness of humankind & on the relationship between biology & ethics zFrancisco Ayala. “Human Nature: One Evolutionist’s View.” Whatever Happened to the Soul? Eds. Warren Brown, Nancey Murphy, & H. Newton Malony. Minneapolis: Fortress, 1998. zThe specialness of humankind has biblical roots (Genesis 1:27). zYet humans emerged in the evolutionary process from other animals. yHominids emerged from chimpanzees 5 - 7 mya yHomo erectus - 1.8 mya

2. Ayala on the uniqueness of humankind & on biology & ethics ~ page 2 Ayala on the uniqueness of humankind & on the relationship between biology & ethics yHomo neanderthalensis appeared in Europe ca. 200,000 tya ago and persisted until 30-40,000 tya. yDebate over the origin of modern humans xMultiregional hypopthesis xAfrican replacement model

3. Ayala on the uniqueness of humankind & on biology & ethics ~ page 3 Ayala on the uniqueness of humankind & on the relationship between biology & ethics ySo what is distinctive about humans? xAnatomical 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)

4. Ayala on the uniqueness of humankind & on biology & ethics ~ page 4 Ayala on the uniqueness of humankind & on the relationship between biology & ethics 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

5. Ayala on the uniqueness of humankind & on biology & ethics ~ page 5 Ayala on the uniqueness of humankind & on the relationship between biology & ethics xDistinctive 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

6. Ayala on the uniqueness of humankind & on biology & ethics ~ page 6 Ayala on the uniqueness of humankind & on the relationship between biology & ethics Social organization & cooperation (division of labor) Legal codes & political institutions xBiological & cultural evolution Are two kinds of inheritance åBiological -- endosomatic åCultural -- exosomatic; makes possible the cumulative transmission of experience & knowledge from generation to generation

7. Ayala on the uniqueness of humankind & on biology & ethics ~ page 7 Ayala on the uniqueness of humankind & on the relationship between biology & ethics Cultural inheritance makes possible cultural evolution åCultural 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

8. Ayala on the uniqueness of humankind & on biology & ethics ~ page 8 Ayala on the uniqueness of humankind & on the relationship between biology & ethics zBiology & ethics yEvolution selected for human intelligence, not for ethics & ethical behavior yHuman intelligence, in turn, has the capacity for ethics & ethical behavior yThus the capacity for ethics is biologically determined, is part of human nature

9. Ayala on the uniqueness of humankind & on biology & ethics ~ page 9 Ayala on the uniqueness of humankind & on the relationship between biology & ethics yBut specific ethical norms are the product of cultural evolution yEthical theories based on evolution tend to commit the naturalistic fallacy -- Herbert Spencer, E.O. Wilson

10. Ayala on the uniqueness of humankind & on biology & ethics ~ page 10 Ayala on the uniqueness of humankind & on the relationship between biology & ethics