Natural Selection Lab
Archaeopteryx fossil Passenger pigeon, which became extinct in
the early 1900s due to human hunting
I’iwi, Hawaiian honeycreeper
By Jane Horlings
History
• Ideas about evolution originated before Darwin
• Aristotle
• Fossils
• Jean Baptiste de Lamarck– Inheritance of acquired
characteristics
Aristotle (UL), Ammonite fossil (UR), Lamarck (L)
History
• Lamarck – Characteristics which an organism
developed during its lifetime were inherited
– Now known to be invalid
History
• Charles Darwin
• H.M.S. Beagle
• South America & the Galapagos
Islands
H.M.S. Beagle (U), Galapagos turtle (LL), Darwin at early age (LR)
History
• Finches in the Galapagos
History
History
• Other scientists and research influenced Darwin’s theory
• Charles Lyell: Principles of Geology
Lyell
History
• Economist Thomas Malthus
History
• Alfred Russel Wallace
Wallace, early (R), and later in life (L)
History
• Darwin proposed that evolution occurs by natural selection
• On the Origin of Species by Means of Natural Selection published in 1859
• Darwin's theory had four parts:
1. Organisms produce more offspring than can survive to reproductive age
2. Members of a population vary and some of these variations are heritable
3. Resources available to a population are limited
4. Organisms with the most favorable traits have differential reproductive success, and those traits are passed to the next generation
History
History
• The synthetic theory of evolution or Neo-Darwinism
Darwin (R), Mendel (L)
Darwin in cartoon from 1800s
History
Darwin died in 1882
• Selection = when some individuals leave behind more offspring than others, and the rate at which they do so is affected by their inherited characteristics
• Selection can be artificial or natural
Selection
Peppered moth
• Artificial selection
Selection
• Biotechnology / Genetic engineering
Selection
• Natural selection
• Natural selection is the result of differential reproduction by members of a population
• “Reproduction of the fittest!”
Selection
See? The offspring in the last
generation now all have the gene
allowing them to be resistant to the
pesticide! This is a great example of
selection!
Selection
End
