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Evolution Intro: Which Came First?

Evolution Intro: Which Came First? . What occurred first?. Age of Dinosaurs Supercontinent (Pangaea) Breaks Up . What occurred first?. Age of Dinosaurs Supercontinent (Pangaea) Breaks Up . Which occurred first? . First jellyfishes, sponges, and worms First Fungi, Bacteria, and Algae .

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Evolution Intro: Which Came First?

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  1. Evolution Intro:Which Came First?

  2. What occurred first? • Age of Dinosaurs • Supercontinent (Pangaea) Breaks Up

  3. What occurred first? • Age of Dinosaurs • Supercontinent (Pangaea) Breaks Up

  4. Which occurred first? • First jellyfishes, sponges, and worms • First Fungi, Bacteria, and Algae

  5. Which occurred first? • First jellyfishes, sponges, and worms • First Fungi, Bacteria, and Algae

  6. What occurred first? • First life in oceans • First land plants

  7. What occurred first? • First life in oceans • First land plants

  8. Evolutionary Misconceptions

  9. “Natural selection involves organisms ‘trying’ to adapt.” http://evolution.berkeley.edu/evosite/misconceps/IEneeds.shtml

  10. “Natural selection gives organisms what they ‘need.’ ” http://evolution.berkeley.edu/evosite/misconceps/IEneeds.shtml

  11. “Evolutionary theory is incomplete and is currently unable to give a total explanation of life.” http://evolution.berkeley.edu/evosite/misconceps/IEneeds.shtml

  12. “Evolution is like a climb up a ladder of progress; organisms are always getting better.” • Not all species evolve to get “better” or more complex – if they are fit to survive in their environment then they will survive http://evolution.berkeley.edu/evosite/misconceps/IEneeds.shtml

  13. What is “Evolution”? • The processes that have transformed life on earth from it’s earliest forms to the vast diversity that characterizes it today. • Deals with significant changes in a species over a period of time  A change in the genes!!!!!!!!

  14. microevolution vs. MACROevolution Microevolution - changes in gene (allele) frequencies and phenotype traits within a population and species. - Happens over a shorter period of time (years).

  15. microevolution vs. MACROevolution • MACROevolution • large-scale evolutionary changes including the formation of new species & taxa. • happens over a much longer period of • Time (centuries, millenia).

  16. Mechanisms of Microevolution 1) Genetic Mutations - A change in the genetic code of an allele - Natural process - The change may have a positive effect, negative effect, or no effect 2) Artificial Selection (“selective breeding”) - Controlled breeding in which individuals that exhibit a particular trait are chosen as parents for the F1 generation - This is not a natural process - Used to produce new breeds or varieties of plants & animals - I.e. “domestication of the wolf into different breeds of dogs” - FYI... “genetic engineering” is another form of artificial selection

  17. Types of Genetic Mutations (a) Insertion - changes the number of DNA bases in a gene by adding a piece of DNA. As a result, the protein made by the gene may not function properly.

  18. Types of Genetic Mutations (b) Deletion - changes the number of DNA bases by removing a piece of DNA.

  19. Types of Genetic Mutations (c) Inversion - an entire section of DNA is reversed.

  20. Genetic MutationsHow do they affect living things? Beneficial – increases the reproductive success of an organism (favoured by “natural selection”) & will therefore accumulate over time. Harmful – reduces the reproductive success of an individual (not favoured by natural selection) & therefore decrease over time. Neutral – has no selective advantage or disadvantage.

  21. Artificial Selection An interesting video http://www.youtube.com/watch?v=nVSJNhUhV-4

  22. Artificial Selection & Domestication • Artificial Selection (“selective breeding”) • Occurs in captivity rather than in a natural setting • Humans choose specific animals & plants to breed based on their desired traits. • Domestication • the changing of members of a species to suit human needs through controlled captive breeding • Example: “Wolves (canis lupus) were the earliest animal to be domesticated. This started around 10,000 years ago. Modern breeds of dogs (canis lupus familiaris) are therefore thought to be a supspecies of wolves.

  23. Problems with Artificial Selection • Limited by genetic variability within the breeding population. • Can reduce the overall genetic diversity of the population & therefore contribute to the loss of biodiversity.

  24. Artificial Selection in PlantsA group activity Several thousands of years ago the wild sea cabbage (Brassicaoleracea) was domesticated. Now, there are a wide variety of vegetables descended from this single plant! Differences in taste & appearance of these vegetables are the result of artificial selection over thousands of generations. Get into groups of 4-5 people. Visit all of the “veggie stations” At each station: (a) analyze the morphology of the vegetable (b) predict what trait was selected for

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