1 / 29

What is Life?

What is Life?. What will happen if organisms reproduce, imperfectly, and the variation makes a difference in survival and reproduction of the organism?.

adonica
Download Presentation

What is Life?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. What is Life?

  2. What will happen if organisms reproduce, imperfectly, and the variation makes a difference in survival and reproduction of the organism?

  3. School children modeled this by drawing copies of a drawing of animal. Then most of these copies were eliminated (disaster or climate change), and they drew copies of the surviving drawings, for 6 successive generations. These drawings were animated to produce this video: http://www.youtube.com/watch?v=N8X-j0dbZWs What will happen if organisms reproduce, imperfectly, and the variation makes a difference in survival and reproduction of the organism?

  4. Evolution is an inevitable consequence of life on Earth • Heritable variation – mutation, recombination. • Competition for limited resources. • Natural selection. • Time – many generations. • Long-term environmental changes.

  5. Hutton’s Unconformity Red sandstone (horizontal) Grey shale (vertical) “… no vestige of a beginning, no prospect of an end.” –James Hutton (photo: Anne Burgess) http://en.wikipedia.org/wiki/Image:Siccar_Point.jpg

  6. Homology of Mammalian Limbs • Buffon (1707-1788) noted the homologous structure of mammal limbs and suggested descent from a common ancestor. • Common structures in four very different mammals: • humerus (gray) • radius (orange) • ulna (beige) • carpals (yellow) • phalanges (brown) Campbell & Reece, Fig. 22.14

  7. Sean Carroll - http://www.hhmi.org/biointeractive/evolution/lectures.html

  8. Sean Carroll - http://www.hhmi.org/biointeractive/evolution/lectures.html

  9. What the fossil record shows Foraminiferans – www.don-lindsay-archive.org/creation/foram_work.gif

  10. Evolution of Horses

  11. Horsetoes!

  12. Darwin's Original Insights • Descent with modification from a common ancestor – a tree describes genealogy of life • Natural selection – the mechanism of evolution

  13. Darwin's Tree Illustrations 1859 Origin of Species – only figure 1837 notebook page

  14. Natural Selection and Time

  15. How often does a black coat mutation arise? Depends on:

  16. How often can we expect a black rock pocket mouse to arise by mutation? Mutation rate for black MCIR allele = 2 x 10-8

  17. Evolutionary hypotheses are testable and falsifiable • Discovery and characterization of new transitional fossils • DNA sequence comparisons • Radiometric and isotopic dating • Geological record • Astrophysics

  18. Thomas Huxley's grandchildren

  19. Modern Biology Is Evolutionary Biology • “Nothing in biology makes sense except in the light of evolution.” • Theodosius Dobzhansky • “The alternative to thinking in evolutionary terms is not to think at all.” • Peter Medawar, Nobel Laureate, 1960

  20. Useful Websites • National Academy of Sciences: Teaching About Evolution and the Nature of Science • A good overview of evolution and science. • UC Museum of Paleontology • Info on the theory and history of evolution • Talk Origins Archive • Info on evolution and creationism • Talk Origins Archive FAQ • A good entry point to the Talk Origins Archive

More Related