J. V. Siry, Ph.D.

The Imperiled Planet

The Dominant Animal: Chapter 4, Of Genes & Culture.

an on line guide

Annie Dillard: Pilgrim, "Living like Weasels"

Richard Lewontin, Genes, The Triple Helix

















"… eaten the storms and folded them into its genes"

E. O. Wilson, Storm, Diversity of Life, p. 15.

"...stores of non-genetic information that are shared and exchanged among them and that may change over time (evolve). Just as humans do, chimps learn from others, and teach others, how to deal with their biophysical and social environments

"the complex cultures of modern human beings …. humanity's vast stores of cultural information have been the key to Homo sapiens' rise to dominance...."

p. 69.

Paraphrase: The variety we see in nature is the product of instinctual behavior from inherited traits on chromosomes and the capacity for acquired traits or learned behavior to assist organisms in responding to external and internal pressures. The interplay of genetic information with environmental conditions requires a constant feedback among genes, proteins, behavior and learned or acquired traits.

Title | Terms | Structure | Table | Details | Summary | Take-away lessons.

Of Genes & Culture  
  what a genome cannot achieve.


"our ability to generate culture."

p. 68

Human     mitotic division  
  chromosomes   cell division: mitosis  

Acquired traits "that is non-genetic information that can be transmitted between generations"… "takes the form of" behaviors and ideas in humans.

" Genes cannot function without an environment. Equally, there cannot be an environment without genes."

p. 86.


  1. the genotype & phenotype differences
  2. the lock & key structure of proteins and their form, or shape
  3. the construct of the phenotype & the niche filled
  4. nourishment & reproduction as tandem functions
  5. the two-step evolutionary process–
    1. immense variability in the offspring–biotic potential
    2. environmental constraints on size & reproduction. ecological resistance


  Vocabulary | Outline | Summary


"This potential multiplicity of consequences from single genetic changes may be why it has been so difficult to demonstrate that natural selection has occurred on more than a tiny fraction of genes during the transition from chimpanzee to behaviorally modern human beings."We cannot "ignore how difficult gene-gene and gene-environment interactions make it for selection to operate on just one attribute of an organism.""we have many fewer than 25,000 independent genes."

p. 94.


descent from common ancestor, genetic versus epigenetic, acquired traits, hard versus soft inheritance, Acheulian, hominin and hominid, society, “great leap forward” or cultural revolution, information, wet ware ,


Drawing of the DNA molecule found in the chromosomes


Title | Terms | Structure | Table | Details | Summary | Take-away lessons.

The duality of our inheritance.

genes culture bicycle
inheritance hard soft
  chromosomes language,
inherited nucleic acids acquired traits
  conditions common beliefs
traits instinct customs
  temperament ideology
  behavior refined



"Inseparable though they are, a dramatic difference between genetic and cultural evolution is the amount of information each has to operate on."

p. 87.

  Vocabulary | Outline | Summary 


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


The Evolution of Culture { 69 "And no other creature depends on culture so completely."

p. 70.

Early human culture { 72

a.    2.5 million years of stone tools (Figure 4.1) { 73

b.    250,000 years ago the Acheulian  progressed to mesolithic


The Great leap forward  { 74

J. Diamond’s phrase for “revolution”


a. brain size changed dramatically from 600 cc to 1680+ cc 800,000-200,000 years ago
     b. Humans are adapted to severe climate change, & the African bottleneck 145,000 years ago


"About 50,000 years ago technology exploded in African Later Stone Age. . . .the most important in our history.

p. 74. Smithsonian


Title | Terms | Structure | Table | Details | Summary | Take-away lessons.


Language leap { 75  “purely arbitrary sounds – to words & concepts” 76


"Intimately connected with the questions of surrounding the great leap forward are those of the development of language with complex syntax, (that is meaning embodied in relationships between the words in a sentence.).


language is tied to "a rich culture."

p. 75.

Culture and the Brain ‘s evolution

p. 77.

                                               i.     mirror neurons” monkeys  & humans { 78                                             


                                               ii.     Size means blood demand is great (20% of the supply)

1.    Synapses & 200 neurotransmitters (2% body mass)

2.    Grew, in part, due to being highly social primates

                                            iii.     Eight qualities of the human brain  {79-81

1.    Evolved– so there is no mind | body duality

--from a common stem with reptiles & mammals

2.    Has capacity to compensate for losses (repair)

3.    Neuronal associations are ancient (Thalamus & Limbic cortex)

4.    Regulates hormonal releases –soma

5.    Memory and recall requires chemical change

6.    Recently evolved neural networks stem from older mammalian cortex

7.    Biased perception & behavior due to natural selection

8.    is programmed by the environment to develop its inherent range of genetic endowments–stereotype


Title | Terms | Structure | Table | Details | Summary | Take-away lessons.


The Mystery of Consciousness

{ 83

sensations vs. perceptions

"Each of us... when awake, is aware of our self. We each have a perpetual narrative running through our head.... Another way to view cultural evolution is as the changing pool of stories being narrated in the brains of human populations, just as their changing pool of genes constitutes genetic evolution."

p. 83.

"He, like many neurobiologists, ties our consciousness to bodily sensation."

p. 83.

"In Humphrey's view, there has been a gradual evolution of consciousness through the shortening of of the sensory feedback loops."

"Nerve impulses arriving in the brain created conscious experiences."


"I feel therefore I am."

p. 84.

Gene -and- Culture Evolution

{p. 86

"Genes cannot function without an environment."

a. Cultural evolution can override genetic evolution in humans {page. 86

"Genes and environment work together to shape the phenotype, the actual observed structural and behavioral characteristics of an individual, and that individual in turn affects the surrounding environment."

p. 86-87.

"The way cultural information dwarfs genetic information is inherent in the contrast between some 25,000 genes, each averaging some 100,00 base pairs, and the information storage capacity of the human brain."


b.    Genetic & cultural evolution, however, interact and the interaction is quite complex.

p. 87

Details of genes --are called hard-- & culture --is called soft-- inheritance.

"Many of human beings most characteristic features, ones much more obvious than the shape of blood cells and necessary for survival as an organism, are undoubtedly programmed into our genes by natural selection and are not often significantly modified by the environment in normal individuals under normal circumstances."

p. 88.

"...gives the erroneous impression that genetic and environmental contributions to human behaviors are actually separable. They are not."

pp. 88-89.

"Perhaps the most interesting thing about all the attention paid to whether 'nature or nurture' controls behaviors is not that individuals with identical genomes often behave very differently [identical twins], but that those same individuals exposed to extremely similar environments also turn out to behave quite differently."

p. 95.




“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.”

Pp. 95-96.

Eukaryotic cells confine nucleic acids to the nucleus of cells bundled into chromosomes.  


All genes are coding stretches of these chromosomes that are interpreted by RNA to make strings of amino acids into functioning proteins. Proteins are the enzymes, hormones, and molecules that catalyze every phase of a functioning organism from reproduction to metabolism, and from birth and growth to death and decay.

Life is not possible without proteins. Gene varieties allow us to trace the evolutionary ancestry of creatures and the similarity of proteins originating from common ancestry enables us to prosper by eating one another to acquire the nutrients that cells use to build the nucleic acids that form the chromosomes that initiate the making of proteins that enable life.

Chromosomes are nucleic acids wrapped around proteins. helix

More on genes: 

Web site: Genes with respect to human inheritance

Why you can never escape the historical past

Genes are a slow way to cope with gradual, periodic, and accumulating environmental changes, but are less well suited for abrupt, aperiodic, stochastic and divergent conditions.

This capacity for adjustment of course depends so much on the rate of reproduction any organisms in a viable species exhibit over time.

Among many species learned behavior or soft inheritance, called culture in social sciences and life sciences, is a primal means of dealing with unexpected shifts in the conditions of existence.

All conditions of existence include physical, chemical (physiochemical) and biological (biochemical) "rules of ecological engagement" -- for lack of a better term for natural settings, functions, and interactions.

First corollary:
Genetic (hard) inheritance and cultural (soft) inheritance that formulate the base and ceiling boundaries for social and individual behavior in any living thing are of course necessary to comprehend in close relation, or dialectically.

Second corollary:
But each form of instinctual as opposed to acquired (traits) inheritance and the behavioral manifestations allowed by these dual mechanisms of inheritance has its own divergent logic that we must explain before we can glibly say that their necessary convergence are prerequisites to constructing the world that constructed and sustains humans as a dominant, yet still co-dependent, animal.

The previous chapter

Vocabulary | Outline | Summary

Title | Terms | Structure | Table | Details | Summary | Take-away lessons.



Readings | Vocabulary | Description | Overview | Assignments | Lectures | Index of this course | Grades

technology index learn science index learn gene index learn social science index learn photograph index learn Darwin Index