Darwin - PowerPoint PPT Presentation

Loading...

PPT – Darwin PowerPoint presentation | free to download - id: 7c7ac3-MTNlM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Darwin

Description:

Darwin s Other Mistake Michael R. Rose and Theodore Garland, Jr. – PowerPoint PPT presentation

Number of Views:43
Avg rating:3.0/5.0
Slides: 12
Provided by: Mr22272
Learn more at: http://sites.uci.edu
Category:
Tags: charles | darwin | theory

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Darwin


1
Darwins Other MistakeMichael R. Rose and
Theodore Garland, Jr.
2
Darwins 1st Mistake
  • Mechanism of heredity wrong
  • Thought an arbitrary number of ductile
    transmissible gemmules moved from organs to
    gonads
  • Gemmules allowed blending along with inheriting
    acquired characters

3
Darwins 2nd Mistake
  • Evolution is gradual and occurs so slowly that it
    cannot be observed
  • 1896 Illinois Corn Experiment selected for oil
    content showed observable evolution
  • Many more studies followed that showed natural
    selection can be observed
  • But most people still believe natural selection
    happens very slowly and is difficult to observe

Charles Lyell
4
Experimental Evolution
  • Definition Research in which populations are
    studied across multiple generations under defined
    and reproducible conditions, whether in the
    laboratory or in nature.
  • The key to keep biology as a fully scientific
    field.
  • More closely resembles physics that most research
    in biology.
  • Emphasizes hypothesis testing, trajectories,
    replication and reproducibility.

5
Macroevolution vs Microevolution
  • Micro evolution within populations
  • Macro change at or above the level of the
    species
  • Speciation is on the fuzzy boundary of both.
  • Macro is difficult to observe because of the time
    involved but scientists use microevolutionary
    analyses to address hypotheses about macro.

6
THE IMPORTANCE OF EXPERIMENTAL STUDIES IN
EVOLUTIONARY BIOLOGYDouglas J. Futuyma and
Albert F. Bennett
7
The major approaches to analyzing evolutionary
processes
  • Experimental Evolution
  • Studies of Natural Populations
  • Comparative methods

8
Experimental Evolution
  • Advantages- Replication and control.
  • Disadvantages suited to laboratory rather than
    to natural situations.

9
Natural Populations
  • Advantage- offer ecological realism
  • Disadvantage - lack of ability to replicate
    results and control variables.

10
Comparative Methods
  • Advantage- widely used method to understand
    evolution of characters in the natural world.
  • Disadvantage-
  • Correlational
  • Assumption of parsimony

11
2 Examples of the Contribution of Experimental
Studies to understand Evolution
  • Trade-offs- adaptive gain and correlated loss.
  • Escherichia Coli
  • Genetic Drift a founder event (or bottleneck in
    population size) may initiate new paths of
    adaptive evolution.
  • Drosophila pseudoobscura
About PowerShow.com