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Evolution - International Baccalaureate Biology - Lecture Slides, Slides of Biology

These are the lecture slides of Biology. Key important points are: Evolution, Kinds of Evolution, Microevolution, Macroevolution, Few Generations, Long Term Effects, Short Term Effects, Fossil History, New Varieties, Baptiste Lamarck

Typology: Slides

2012/2013

Uploaded on 01/24/2013

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Evolution I.
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Evolution I.

EVOLUTION

  • gradual unfolding of new varieties of life from

previous forms over long periods of time (Darwin)

  • from the genetic perspective : a change in allele

frequency from one generation to the next

  • TWO KINDS OF EVOLUTION
    • microevolution – short term effects occuring over just a

few generations

  • macroevolution – long-term effects through fossil history,

large changes produced only after many generations

JEAN BAPTISTE LAMARCK

(1744 – 1829)

  • Popularised the idea of evolution
  • First scientific evolution theory
  • Basic concepts of the Lamarck’s theory:
    • emphasis on the dynamic interaction of organic forms

with the environment

  • environment affects and induce change in organic forms
  • acquired characteristic is passed through heredity to the

next generations

GEORGES CUVIER

  • the „father“ of zoology, palaeontology, and

comparative anatomy

  • criticised Lamarck’s views on evolution
  • proposed theory of catastrophism:
    • series of violent and sudden catastrophes
    • all of creatures were destroyed during the catastrophe
    • after things settled down, areas were restocked with new

organisms different from those previously living there)

Charles Darwin

stopover at the Galápagos Islands

- Darwin described 13 species of finches resembled one another in the structure of their beaks, body forms, and plumage

Darwin´s finches

The fate of the Darwin's theory

Alfred Russel Wallace

(1823 – 1913)

  • 1855 –published an article

concerning the succession

of species and their

mutability

RECENT CHALLENGES

TO THE MODERN SYNTHESIS

  • neutral mutations
    • Much of variation in natural population is due to neutral mutations and chance factors (i.e. genetic drift).
    • Neutral mutations are not controlled by natural selection.
    • “Natural selection is the editor, rather than composer of genetic message” (King and Jukes 1969)
  • gradualism X punctuationalism
    • gradualism – evolution changes accumulate gradually in evolving lineages
    • punctuationalism (punctuated equilibrium) – evolution is nongradual process, evolutionary rates are not constant, the evolution is a process of long stasis and sudden quick spurts

MECHANISMS OF EVOLUTION

  • Factors that produce and

redistribute variation

  • mutation
  • migration
  • genetic drift
  • recombination
  • Natural selection
  • differential net reproductive success
  • Some of genetic variations among individual

within a population may influence reproductive

success. Therefore some individuals contribute

more offspring to succeeding generations.

http://www.pbs.org/wgbh/evolution/index.html

Public Broadcasting Service

  • www section about evolution

EARLY EVOLUTIONARY HISTORY

  • The origin of Earth
    • 4,5 – 4,6 thousands million years ago
  • The oldest fossils were found in

3,8 thousands million years old sedimentary

rocks from Greenland (the oldest terrestrial

rocks).

What happened during the prebiotic

evolution?

Urey-Miller

experiment

The Urey - Miller experiment