Name ______Date ______Period _____
Evidence for Evolution by Natural Selection
Raven Ch.22
Big Idea 1: THE PROCESS OF EVOLUTION DRIVES THE DIVERSITY AND UNITY OF LIFE.
It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.
―Charles Darwin (1859)
Essential Knowledge:
- Natural selection is a major mechanism of evolution
- Natural selection acts on phenotypic variations within populations.
- Evolutionary change is also driven by random processes.
- Biological evolution is supported by scientific evidence from many disciplines including mathematics
- Organisms share many conserved core processes and features that evolved and are widely distributed among organisms today.
- Phylogenetic trees and cladograms are graphical representations (models) of evolutionary history that can be tested
- Speciation and extinction have occurred throughout the Earth’s history.
- Speciation may occur when two populations become reproductively isolated from each other.
- Populations of organisms continue to evolve.
- There are several hypotheses about the origin of life on Earth, each with supporting scientific evidence.
- Scientific evidence from many different disciplines supports models of the origin of life.
Natural selection is a major mechanism of evolution
What are the 4 lines of evidence that support Darwin’s ideas?…
- Fossil Record
Transitional Fossils
Evolution of ______
- ______-, the earliest known flying bird from the Late Jurassic period, exhibits many shared primitive characters with therapod (bird-like) dinosaurs. such as teeth, a long bony tail and pinnate feathers. However, Archaeopteryx possessed asymmetrical flight feathers on its wings and tail, together with a wing feather arrangement shared with modern birds. This suggests some degree of powered flight capability but, until now, little was understood about the extent to which its brain and special senses were adapted for flight.
- lived about 150 mya
- links ______
Evolution of ______
- 2006 Fossil Discovery of Early Tetrapod
- “______”
- “______” from sea to land animals
- from ______(0 legs) to ______(4 legs)
Evolution of ______
- Whales as land creatures returning to the ______
- 4-5 intermediate forms all found in last 2 decades
Notes on video: ______
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- Artificial Selection
Examples: ______,
______,
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Insecticide and drug resistance:
- insecticide ______all individuals
- resistant survivors ______
- resistance is ______
- insecticide becomes less & less ______
Examples: ______,______,
- Anatomical Evidence
- Homologous structures
- Similar ______
- Similar ______
- Different ______
- Evidence of close ______
- recent ______
- Examples: Animals-______, ______, ______,______,______,
Plants-______, ______, ______,______,______,
- Analogous structures
- Solving a similar ______with a similar ______
- Do they have a recent common ancestor? ______
- A result of ______
- Examples: 1. ______and ______
2. ______and ______
- Convergent Evolution
- Mammals- ______v. ______
- Vestigial structures
- These are ______of structures that were functional in ______
- Examples: ______,______,
- Molecular Record
- Comparing ______structure
- ______genetic code!
- DNA & RNA
- Compare ______genes
- ______C (respiration)
- ______(gas exchange)
- Closely related species have sequences that are ______than distantly related species
- The sequence in DNA & proteins is a ______record of evolutionary ______.
- Why compare these genes? ______
______
- What can we do with the results of these comparisons among organisms?
______
- Essence of Darwin’s ideas
- Evolution by Means of Natural Selection
- ______exists in populations
- ______-more offspring than the environment can support
- ______-for food, mates, nesting sites, escape predators
- ______-successful traits = adaptations
- ______-adaptations become more common in population
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