Weasels, genes, culture and the mercurial role of instinct



      The nature versus nurture argument obscures as much as it      

reveals about life on earth.


background | seven related findings | essay | argument | dialectical approach | conclusion




            Dillard                        instinctual living – reason and “passion”

        Ehrlich & Ehrlich      Genes (hard inheritance) & Culture (soft inheritance)


Humans are “not alone in the capacity to pass along non-genetic information–culture”



chapter iv. The Dominant Animal


Terminology used:





            acquired traits (soft inheritance)                          genetic (hard inheritance)

                        nurture                                                                       nature

                        learned behavior                                                     instinct

                        practiced                                                                 hard wired


Essay due

“How do we describe nature?


What do I owe the world and nature?”


1.     Dillard, Carson, and Wilson on what we “owe” one another.


2.     Ehrlich & Wilson & Diamond – on the enduring complexity of nature.

                                    Wilson on genes




Humans are organisms and are the products of inheritance, behavior, and culture (nature & nurture)


"When organisms evolve, they also change the environments of other organisms."

"Changing environments change organisms; changing organisms in turn change environments: that's pretty much the central story of life on earth."


"inability to evolve in the face of environmental change."


p. 20, Ehrlich Chapter One.


background | seven related findings | essay | argument | dialectical approach | conclusion

Seven points in Ehrlich & Ehrlich

            Language and tools

            Development of culture and early humans

            Brain evolution (changes in the central nervous system over time)

                        Mirror neurons: learning & empathic responses

                        Volume of blood needed for neuromuscular control

            Eight qualities of the human brain

            Consciousness and the “unconscious” or instinctive – impulsive character

            Sympathetic tension in relations between genes & culture–human are dualistic


background | seven related findings | essay | argument | dialectical approach | conclusion

            The dialectical means of examining the world is a basic concept:


                        Thesis       +       antithesis          =       synthesis




We are determined by our genes.



                                      No, we are more influenced by our culture.




                                               Together humans are enriched by both genes and culture working in tandem.




            “In summary, as we learn more about the human genome, the notion of ‘genes   

         for behavior’ must be discounted. For example traits such as normal behaviors  

         few cases have been found of a specific gene or even many genes that greatly   

         influence variation in the trait. It is becoming clear that when genes influence    

         traits, and this applies especially to behaviors, they will do so in a way that is    

         strongly mediated by the environment.”


“Environmental circumstances during any phase of life may alter the way in

which an individual’s genes function at that time and later.”



Ehrlich, page. 96.

The case of the disappearing frogs.


Frog eggs are deposited in water.


In the tadpole (larval) stages free swimming young feed on organisms in the water.


As the initial place of origin whatever nutrients and chemicals are dissolved in the water affect young, developing frogs.


Today, worldwide there is deterioration in frog populations.

The causes of these declines are not certain, but there is indication that a fungus is inhibiting (a form of predation) the survival of frogs.


Effects of Chytrid fungus and parasitic flies on frogs.

 background | seven related findings | essay | argument | dialectical approach | conclusion


The Dominant Animal on the web


related class site


Class index

measuring ecosystem services.

The Imperiled Planet | The Dominant Animal | Storm Over the Amazon | The Tragedy of the Commons | The Web of Life

ecology vocabulary