Biodiversity

1
Biodiversity

• We are leading up to ecology

2
Biological tool kits

• Homologous structures
• Example Wings, flippers, arms, legs
• Formed from similar tissues
• Modified in different ways
• Some tools are visible
• Lungs, claws, wings
• Some tools are invisible
• Protein synthesis, respiration
•  Evolution modifies existing tool kits frequently

3
Adaptive Radiation

• A new tool kit appears
• A kind of evolution
• When a newly evolved species or a group of
  organisms in a new area evolve, sometimes very
  quickly, into different species that live in
  different ways, this pattern of evolution is
  called adaptive radiation.
• Example The Finches

4
Convergent Evolution

• Adaptive radiation can lead to unrelated
  organisms feeding, flying, moving, and hiding in
  similar ways.
• This is the independent evolution of superficial
  similarities in unrelated organisms because of
  adaptations to similar environments
• Results in analogous structures
• Ex. woodpeckers, honeycreepers, opossum, aye-aye
  (lemur)
• Bird wings and insect wings
• Streamlined body shapes

5
Molecular unity of life

• Homologous Structures (again)
• Allow biologists to piece together evolutionary
  relationships
• Morphological basis for cladistics (remember)
• Biochemical evidence for evolution
• The same genes are shared by many organisms
• Proteins are homologous structures too
• Example myosin in yeast, hemoglobin, cytochrome
  c

6
Biodiversity (1)

• Variety of organisms (microbiological, plants,
  animals)
• All of their genetic information
• All of the biological communities they live in

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Biodiversity (2)

• Ecosystem diversity
• All the habitats, communities and processes
• Organisms are adapted to every part of the planet
• Species diversity
• Presence of absence of species can change the
  nature of life in an area
• Genetic diversity
• Inheritable variation is the raw material for
  natural selection

8
Molecular clocks

• Analysis of different parts of DNA allow
  biologist to work out when mutations occurred
• Fast clocks vs. slow clocks
• Some regions of genes mutate quickly, others
  slowly (i.e. we say highly conserved)