what is life
Download
Skip this Video
Download Presentation
What is Life?

Loading in 2 Seconds...

play fullscreen
1 / 29

What is Life? - PowerPoint PPT Presentation


  • 67 Views
  • Uploaded on

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

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' What is Life?' - adonica


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2
What will happen if organisms reproduce, imperfectly, and the variation makes a difference in survival and reproduction of the organism?
slide3

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?
evolution is an inevitable consequence of life on earth
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.
hutton s unconformity
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

homology of mammalian limbs
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

slide7

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

slide8

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

what the fossil record shows
What the fossil record shows

Foraminiferans – www.don-lindsay-archive.org/creation/foram_work.gif

darwin s original insights
Darwin\'s Original Insights
  • Descent with modification from a common ancestor – a tree describes genealogy of life
  • Natural selection – the mechanism of evolution
darwin s tree illustrations
Darwin\'s Tree Illustrations

1859 Origin of Species – only figure

1837 notebook page

how often can we expect a black rock pocket mouse to arise by mutation
How often can we expect a black rock pocket mouse to arise by mutation?

Mutation rate for black MCIR allele = 2 x 10-8

evolutionary hypotheses are testable and falsifiable
Evolutionary hypotheses are testable and falsifiable
  • Discovery and characterization of new transitional fossils
  • DNA sequence comparisons
  • Radiometric and isotopic dating
  • Geological record
  • Astrophysics
modern biology is evolutionary biology
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
useful websites
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
ad