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					How to study ecology?
Lab Experiments
Field Experiments




           Pelvetiopsis
Rothamsted, England – Broadbalk Wheat Experiment
Rothamsted,
England –
Park Grass
Experiment
   Natural snapshot experiment




Succession following avalanches at different times
Natural trajectory experiment




    Eruption of Krakatau – 1883
Evolutionary Ecology
Bird Adaptations
                 Evolution

• Evolution simply means change and
  biological evolution can be defined as
  changes in any attribute of a population
  over time
• Evolutionary changes that lead to adaptation
  must involve a change in the frequency of
  individual genes in a population from
  generation to generation
                       Parus caeruleus

Adaptation – process which leads to
 survival and reproduction of
 characteristics beneficial to an organism
 in a particular environment
Perfect Adaptation? Hmm…
Charles Darwin
Age 46
Alfred Russel
Wallace –
in his 70’s
        Evolution by Natural Selection

1. Individuals in a population of a species are not identical.
2. At least some of this variation is heritable.
3. All populations have very high reproductive potential, but
   they seldom achieve it. Mortality and less than maximum
   reproductive rate keeps them from taking over the earth -
   e.g. oysters
4. Different individuals leave different numbers of
   descendents. - this is where idea of fitness comes in
5. The number of descendents an individual has, depends on
   the interaction between the characteristics of the individual
   and its environment.
Two major points about natural selection

1. Variation among individuals arises due to
  chance mutations.
2. Individuals survive in today's environment
  because it is similar to their ancestors
  environment - adaptation is not planned or
  purposeful
 What is selected?




The individual is selected.
Some of Bumpus’s survival data
Peppered Moth – Biston betularia – white and melanistic forms
on lichen covered and sooty trees
Distribution of Peppered Moths in Britain
  Left map shows distribution in 1956, right map shows
  distribution in 1996; Dark part of circle shows proportion of
  dark form, light part of circle shows proportion of light form
Life stages of
Coho salmon –
top to bottom –
Eggs, fry, oceanic
Silverfish,
Hooknose male,
and female
Coat Color Mutation in Florida Beach
  Mouse – Peromyscus polionotus




   Normal, dark mainland mouse on right; lighter
  mutated island beach mouse on left; mutation due
         to a change in a single nucleotide
Coat Color Mutation in Florida Beach
  Mouse – Peromyscus polionotus
Gene Flow in Walleye
Walleye sampling sites
Walleye relatedness tree
Chimpanzee Hands And Feet
Drought Cycles in Iran
Phylogenetic Constraint – Egg Size
  and Brood Patch in Penguins
Environmental or Genetic
  Variation in Yarrow?
Local adaptation in bentgrass Agrostis stolonifera
Trinidad Guppies - Poecilia reticulata




                        Male and Female




   Two males
Adaptation and natural selection in
       guppy populations




John Endler

				
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posted:9/29/2012
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