Evolution by Natural Selection. No Genetic Change Through Time (no evolution). Scientists believed that all organisms were exactly how they have always been. Then Lamarck came to town. Jean Baptiste Lamarck French biologist Explained evolution! Wrong Acquired Traits. - PowerPoint PPT Presentation
Evolution byNatural Selection
1No Genetic Change Through Time (no evolution)Scientists believed that all organisms were exactly how they have always been.
Then Lamarck came to townJean Baptiste LamarckFrench biologist
Explained evolution! Wrong
Artistic ability, Math ability, etc.
Darwins LifeCharles DarwinWanted to be a doctorCouldnt stand the sight of blood
Married his cousin
Sea voyagesVoyage of BeagleNaturalist
On the HMS Beagle5 year journeyObserved flora/fauna everywhere he wentCataloguedComparedDeveloped his theory based on observations and evidence.Wrote several booksMost famous was On the Origin of Species
P.S. Mr. Chaneys Favorite Book by Darwin is . . . Drum roll please . . .
The Formation of Vegetable Mould Through the Action of Worms.
Darwins TheoryDescent with Modification.All species arise from pre-existing species
Generations pass, and species may change if the population has:
Genetic VariationAn Overproduction of offspringA Struggle to SurviveDifferential Reproduction*********Darwinian Fitness *********
So no one else figured this out until Darwin?!?!Who has greater Darwinian Fitness?
Evidence for Evolution: FossilsFossil RecordRocks form in layers
Organisms in deeper, older rock, are older
Different organisms lived at different times
Todays organisms are different from those of the past
Pennyslvanias State Fossil! The Trilobite
Example of Fossil that supports evolution
Fossils in adjacent layers are more alike than fossils from far apart layers
Evidence of Evolution: Transitional Species
Fossils of in-between organismsUsed as a timeline!Speaking of trilobites . . . . Heres a Pakicetus! (not a good transition!)Pakicetus14Vestigial Traits
Vestige- a mark, trace, or sign15Archaeopteryx
Bird? Or Reptile?Vestigial Traits
Diptera-Vestigial WingsSnake spursVestigial Wings in DrosophilaXanthopan morganii praedictaPredicted MothDarwin predicted its existence before it had been observed.Ridiculed by other scientistsOrchids have specific pollinators
Lets Process!1. How does the presence of vestigial traits support the theory of evolution by natural selection?
2. Why is variation necessary for natural selection to occur
3. If a natural disaster wiped out all the small seeds in an area with a population of birds with varying beak size, how might the population be affected?Darwinian Fitness
Who has GREATER fitness from the perspective of Darwin, and the theory of natural selection?