Changing habitats, changing populations?

1
Changing habitats,changing populations?

• Life-history evolution of coexisting Drosophila
  species in a heterogeneous environment.

Kim van der Linde , Institute for Evolutionary
and Ecological Sciences, Section Animal Ecology
and Section Evolutionary Biology, Leiden
University, The Netherlands.
2
Changing habitats, changing populations?

• Darwin finches (Grant Grant)
• Beaksize variation between generations is
  correlated with size of available seed.
• Guppies (??)
• Life-history strategies vary with predator.
  Transplantation to other stream with other
  predator induces evolution to the other strategy.
• ???
• Add self more examples!

3
A life history trade off and community structure
in a variable environment.

• The environment is variable through the year.
• Species differ in life-history.
• A short development time is an advantage when
  fruit is abundant.
• A long survival time under food stress is an
  advantage when fruit is scares.
• A physical trade-off between development time and
  starvation resistance make that different species
  have a competitive advantage during different
  times of the year!

• Sevenster JG van Alphen JJM (1993) J. Anim.
  Ecol. 62 720-736.

4
Changing habitats

• Changes in
• vegetation structure
• fruit availability
• temperature
• humidity
• .

5
Which traits?

• Ecological important traits
• Development time
• Starvation resistance
• Life-history model of Sevenster van Alphen
  (1993)
• Body size
• Egg size (Relative egg size)
• Extension to the model by Toda Kimura (1996)

6
Different habitats

• Habitats differ in year round breeding substrate
  availability.
• Local populations are likely to adapt to those
  differences.
• Expected result is that populations from
  different habitats from the same species will
  show differences in the life-history traits.

7
Philippines 1994

• Collecting flies from four habitats secondary
  forest, forest edge, kaingin and grassland.
• Bring them to a common environment of the lab.
• Measuring development time and starvation
  resistance.

8
Development times
9
Starvation resistances
10
Conclusions and questions

• Habitat related variation between populations in
  development time.
• Variation is of same pattern for all (7) species
  of the Sophophora subgenus.
• But what are the realized values in the field?
• Are some or all traits genetically correlated?

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Common environment versus real environment
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Genetic correlation's in D. melanogaster
Development time


0
0
Body size

0
Longevity

Starvaton resistance / fat content
Source Zwaan, BJ (1993) Genetical and
environmental aspects of aging in Drosophila
melanogaster. Ph.D. thesis, Groningen
13
Questions after that

• Does natural selection shape the life-history
  traits even throughout the year?
• E.g. are there differences within flies collected
  in different times of the year?

14
Panama 1998

• 1 Expression of life-history traits in the
  original habitat
• 2 Transplantation experiment, offspring of many
  females
• 3 Transplantation experiment, offspring of a
  single female

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Experiment 1
Transect 1
Transect 2
Hab. C
Hab. A
Hab. B
Hab. A
Hab. B
Hab. C
All stocks
All stocks
All stocks
All stocks
All stocks
All stocks
Transect 1
Transect 2
Hab. C
Hab. A
Hab. B
Hab. A
Hab. B
Hab. C
16
Experiment 2
Transect 1
Hab. C
Transect 2
Hab. A
Hab. B
Hab. A
Hab. B
Hab. C
Hab. A of transect 1
Species 1 of Hab. A
Species 2 of Hab. A
Species 3.. of Hab. A
Replica 1
Replica 1
Replica 2
Replica 2
Replica 3
Replica 3
Species 1 of Hab. B
Species 2 of Hab. B
Species .. of Hab. B
Replica 1
Replica 1
Replica 2
Replica 2
Replica 3
Replica 3
17
Experiment 3
Transect 1
Transect 1
Hab. C
Transect 2
Hab. A
Hab. A
Hab. B
Hab. A
Hab. B
Hab. B
Hab. C
Hab. A
Species 1 of Hab. A
Species 2 of Hab. A
Species 3 of Hab. A
Species 1 of Hab. A
Species 2 of Hab. A
Species 3 of Hab. A
Species 1 of Hab. A
Species 2 of Hab. A
Species 3 of Hab. A
Species 1 of Hab. A
Species 2 of Hab. A
Species 3 of Hab. A
Replica 1
Replica 1
Replica 1
Species 1 of Hab. A
Species 2 of Hab. A
Species 3 of Hab. A
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 3
Replica 3
Replica 3
Species 1 of Hab. B
Species 2 of Hab. B
Species 3 of Hab. B
Species 1 of Hab. B
Species 2 of Hab. B
Species 3 of Hab. B
Species 1 of Hab. B
Species 2 of Hab. B
Species 3 of Hab. B
Species 1 of Hab. B
Species 2 of Hab. B
Species 3 of Hab. B
Replica 1
Replica 1
Replica 1
Species 1 of Hab. B
Species 2 of Hab. B
Species 3 of Hab. B
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 1
Replica 1
Replica 1
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 2
Replica 2
Replica 2
Replica 3
Replica 3
Replica 3
Replica 3
Replica 3
Replica 3
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Experiment 2 3
Transect 1
Transect 2
Stocks
Hab. C
Hab. A
Hab. B
Hab. A
Hab. B
Hab. C
Transect 1
Transect 3
Hab. C
Hab. A
Hab. B
Hab. A
Hab. B
Hab. C
Expe- riment