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Evolution

Evolution. Mr. Jeff Peterson Fulbright Exchange Teacher from Indiana, USA. EVOLUTION. Evolution is any change across successive generations in the heritable characteristics of biological populations . Change over time giving rise to… Diversity Species Individual organisms DNA/proteins .

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Evolution

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  1. Evolution Mr. Jeff Peterson Fulbright Exchange Teacher from Indiana, USA

  2. EVOLUTION • Evolution is any change across successive generations in the heritable characteristics of biological populations. • Change over time giving rise to… • Diversity • Species • Individual organisms • DNA/proteins

  3. EVOLUTION • Evolution makes no claim to explain how life began on Earth. • Evolution only explains the mechanisms of how that life changed. • Repeated speciation and the divergence of life can be traced through shared sets of biochemical and morphological traits.

  4. EVOLUTION • Homologous traits and sequences are more similar among species that share a more recent common ancestor. • Evolutionary History

  5. EVOLUTION • Evolutionary thought or change over time has been around since before the Greeks. • Charles Darwin first to propose the mechanism for change was natural selection.

  6. EVOLUTION • Evolution by natural selection is a population level process that is inferred from three facts: • more offspring are produced than can possibly survive • traits vary among individuals, leading to differential rates of survival and reproduction • trait differences are heritable

  7. EVOLUTION • When members of a population die, they are replaced by individuals that are not born from random parents. • New members are born from parents that are better adapted to the environment in which natural selection took place. • Evolution of traits that are seemingly fitted for the functional roles they perform.

  8. EVOLUTION • Causes of evolution (change over time) • Natural Selection – Adaptive • Mutation – Non Adaptive • Genetic Drift – Non Adaptive

  9. EVOLUTION • Natural Selection

  10. EVOLUTION • Natural Selection

  11. EVOLUTION • Types of Natural Selection • Disruptive • Stabilizing • Directional

  12. EVOLUTION • Genetic drift or allelic drift is the change in the frequency of a gene variant (allele) in a population due to random sampling.

  13. EVOLUTION • Acquired Traits and Inherited Traits • Acquired Traits are traits none reproductive changes… • Knowledge • Inherited Traits are traits which are passed along to offspring… • Beetle color

  14. EVOLUTION • Speciation is the process by which new species arise.

  15. EVOLUTION • Evolutionary Relationships • Homologous Organs - the same organ in different animals under every variety of form and function. Common Ancestor

  16. EVOLUTION • Evolutionary Relationships • Analogous Organs - the same function yet phylogenetically independent.. No Common Ancestor

  17. EVOLUTION • Homology - traits inherited by two different organisms from a common ancestor • Analogy - similarity due to convergent evolution, not common ancestry

  18. EVOLUTION

  19. EVOLUTION

  20. EVOLUTION • Trees NOT ladders • Humans did NOT evolve from chimpanzees • Humans are NOT "more evolved"

  21. EVOLUTION • How we know what happened when • Radiometric dating relies on half-life decay of radioactive elements to allow scientists to date rocks and materials directly. • Stratigraphy provides a sequence of events from which relative dates can be extrapolated. • Molecular clocks allow scientists to use the amount of genetic divergence between organisms to extrapolate backwards to estimate dates.

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