Theory, Evolution

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Theory, Evolution Ecology

• Explaining change

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Outline

• Two definitions
• Culture Ecology
• Evolutionary Theory
• Myths about evolution
• A review of time, space, form
• Absolute relative dating

www.victorianweb.org
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Definitions

• Sites (forgot, should be w/ artifact feature)
  clusters of associated artifacts.
• How many artifacts are enough?
• Ends up being artifacts that are in the way.
• Culture shared ideas (put to work).
• Humans extrasomatic means of adaptation.
• Enculturation the transmission process.
• Because culture is transmitted, it evolves.

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Culture is adaptive

• Adaptation a process of adjustment to changes
  in the environment.
• Can also be thought of as an adaptation, which
  is a state of adjustment to an environment.
• Environment physical social surroundings.
• When this changes, organisms (humans) have three
  possible responses
• MOVE, ADAPT, or DIE!

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Ecology

• The study of interactions among living beings
  the environments that surround them.
• A study of relationships.
• Studies patterns, networks, cycles
• Darwin referred to these as the Web of Life.
• Quammen reading.

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Complexity connectedness the web of life
Landres 1992
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Important Concepts in Ecology

• Ecosystem a set of relationships cycles
  between organisms their surroundings.
• Nested, small systems exist inside large ones.
• Capable of cycling nutrients, oxygen, carbon,
  etc.
• Niche an organisms lifestyle or strategy.
• Where it fits into an ecosystem.
• A group of strategies to meet basic needs.

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Important Concepts, contd.

• Habitat where an organism lives.
• Contrast to niche, which is how an organism
  goes about using that space.
• Carrying Capacity how many organisms an
  ecosystem can support without is relationships
  failing.

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Complexity connectedness CHANGE
Landres 1992
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Evolution

• Any change in these interactions creates change
  throughout the entire system.
• Websters evolution a process of unfolding.

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A formal definition

• Biological evolution a shift over time in the
  proportion of organisms differing genetically in
  one or more traits.
• Happens because what is optimal in one setting
  might no longer be so when change occurs.
• This a shift in optimal strategy.
• An adaptive solution that works to survive in an
  environment.

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Evolution, contd.

• Optimal strategy is the survival of individuals
  with alleles (genes) that have high fitness in a
  particular environment.
• Genes sequences of DNA that convey information
  on biology of organisms via copying.
• DNA strands of nucleic-acid combinations found
  in cells.
• Alleles alternative genes that are available in
  the gene pool of a population.
• Gene pool the set of genes in a population.
• Can be thought of as a populations genetic
  options set.

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www.biologycorner.com
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Two more terms

• Genotype the genetic makeup of an individual.
• Phenotype the physical expression of ones
  genotype in an environment.

www.synthstuff.com
Texas AM
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A shift in optimal strategy
Time 1
Time 2
Walker et al. 2001, figure 13.1
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Natural Selection

• Differential success in the reproduction of
  different phenotypes from interactions of
  organisms w/their environment.
• A major force in evolution.

I have called this principle, by which each
slight variation, if useful, is preserved, by the
term Natural Selection. - Charles Darwin, The
Origin of Species
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www.globalchange.umich.edu
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w3.dwm.ks.edu.tw
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Extinction

• The death of a species or the end of an
  evolutionary lineage (path or history).
• When the last members of a population from the
  same gene pool die.
• Produced by environmental change that demands
  optimal strategy beyond the genetic options set.

www.macgamer.com
www.nature.ca
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Peppered Moths (Biston betularia) in Britain

• The pre-pollution common genotype was light
  colored.
• Mimicked lichens on tree trunks.
• Sooting of tree trunks by industrial pollution
  changed their color.
• Led to a change in optimal strategy.

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Walker et al. 2001, figure 13.9
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Recovery of the moth with pollution control
Walker et al. 2001, figure 13.10
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What if soot was hot pink?

• There is no genotype corresponding phenotype in
  the peppered moth that is hot pink.
• Hot pink is beyond the genetic options set of the
  peppered moth.
• It would not have a new optimal strategy within
  its gene pool to shift to.
• Extinction would be the result.

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Gene Flow

• What if there are hot pink alleles in another
  population from, say, Russia?
• If individuals with this genotype could get to
  Britain successfully interbreed with British
  peppered moths, the genetics option set would
  expand.
• Movement of genes from one population to another
  is gene flow.
• An important source of new genetic variation for
  biological populations.
• Often populations from the same species are
  separated geographically.

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Genetic Drift

• Genetic drift changes in the gene pool of a
  population due to chance.
• What if all of the moths with the hot pink
  genotype got sucked through a jet engine all at
  once.
• Improbable, completely the result of being in the
  wrong place at the wrong time.

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Mutation (infidelity in copying)

• Periodically DNA copying produces errors in the
  sequence of nucleic-acid combinations that
  comprise genes.
• This is mutation.
• Often mutations are deleterious.
• Sometimes they are advantageous.
• This is an important way for genetic options sets
  to expand.

www.cdc.gov
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Evolution
Nature encourages no looseness, pardons no
errors- Ralph Waldo Emerson

• So, evolution occurs when.
• Natural selection occurs
• Extinction occurs
• Mutation occurs (bad or good)
• Gene flow occurs
• Genetic drift occurs
• Over long periods, these have enormous cumulative
  effects that cause evolution.

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Cultural Evolution

• Invention (mutation)
• Meme pool (idea pool)
• Diffusion (idea flow)
• Cultural selection
• Cultural variation evolves through many of the
  same processes as biological variation.

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Theory of Evolution

• Has multiple concepts principles useful for
  examining changes in culture biology.
• Allows scientists to infer causes of change.

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Evolutionary Myths

• Progressive evolution
• Lewis Henry Morgan
• Edward Tylor
• Herbert Spencer survival of the fittest.
• Psychic unity of mankind.
• Does not explain cultural diversity.

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Foragers
Horticulturalists
darkwing.uoregon.edu
news.nationalgeographic.com
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www1.fao.org
Pastoralism
www.case.edu
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www.brukeroptics.com
Agriculture Agriculture was only invented within
the last ten thousand years.
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Branching Evolution

• Modern cultural diversity is much better
  conceived using a tree metaphor.
• Modern cultures are simply branches on the tree
  evolving in their one environments.
• Reticulate evolution exist in culture but not in
  biological evolution.

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Human Antiquity

• The reasons why archaeology began
• Archaeological Science 2800

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Early Attempts (1600s)

• How old is the world?
• Bishop James Ussher.
• Biblical foundations to inquiry of the past.

www.bibleprobe.com
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Extinct Beast RemainsSome Highlights

• Jacques Boucher de Perthes (1830s)
• Somme River Valley of France
• Geological Society of London (1858)
• Charles Lyell
• Brixham Cave
• On the Origin of Species (1859)
• Charles Darwin

www.d.umn.edu
www.cnrs.fr
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Summary

• Geologists used the three principles to determine
  that humans were old.
• Superposition
• Association
• Strata identified by fossils
• CH, CR, CP all grew out of this history because
  humans were old.
• We are almost ready to examine the archaeological
  record itself.