Date
Period / Life Science
Evolution Notes
Evolution- ______
Charles Darwin (1809-1882)
· Wasn’t the first one to recognize that evolution has happened and is happening
· Was the first to propose a feasible mechanism for evolution. It is called ______
· Scientists have found large amounts of evidence to support Darwin’s views of evolution.
Theory- ______
*Remember: The word “theory” in everyday language and in scientific language means very different things.
· In everyday language, people use the word theory to mean a hypothesis or an educated guess.
· In science, people use the word theory to represent an idea that is strongly supported by evidence. It is accepted and used to explain many observations.
Other examples of scientific theories:
What was Darwin’s Theory of Evolution by Natural Selection?
· Darwin published his book, On the Origin of Species by Means of Natural Selection, in 1859. In it he outlines the major points of his theory.
Natural Selection- ______
______
You can remember the main points behind natural selection as VISTA.
Variation
Inheritance
We now know that heritable variation is due to genes. Variation in genetic material is due to:
1. Mutations
2. Sexual Reproduction
Survival and Reproduction
· Natural selection is often referred to as “survival of the fittest”. What is “fitness”?
Time
Adaptation- ______
______
· Darwin referred to this accumulation of adaptations over time as ______
· He believed that descent with modification had created the great diversity of life.
Let’s explain the giraffe’s long neck using the theory of evolution by natural selection.
How did Darwin develop his idea of natural selection?
1. Voyage of the Beagle
· After graduating from college, Darwin took a job as a naturalist on the H.M.S Beagle, a boat that was traveling around the world with the purpose of creating better maps.
· Darwin collected living organisms, fossils and other evidence of living things every time the ship landed in a new area.
What did Darwin observe on his travels?
1. Fossils- ______
Darwin wondered…
2. Organisms on Islands
· Studied the finches and giant tortoises of the Galapagos Islands
· Found that organisms on the islands were similar to those on the mainland, but had slightly different characteristics that allowed them to survive in their new habitats.
Darwin wondered…
2) Influence of Other Scholar’s Work
Lamark’s Theory of Evolution through the Inheritance of Acquired Characteristics
1. Use and Disuse
2. Inheritance of Acquired Characteristics
Example: Giraffe’s Long Neck
Does Lamark’s theory of evolution work?
KEY IDEA: Lamark was wrong, but we can learn from his mistakes. Acquired traits aren’t inherited. Only traits determined by our genes are inherited. During Darwin’s time, people did not know how traits were inherited. They had no knowledge of genes and DNA.
3. Personal Studies
· Darwin wanted to ensure that he had as much research as possible to support his ideas.
1. Studied the diversity of barnacles
2. Bred Fancy Pigeons
Artificial Selection-______
Evidence for Evolution
1. Fossil Record
2. Biogeography
3. Comparative Anatomy
Homologous Structures- ______
Examples:
Vestigial Organs- ______
Examples:
Homologous Bones in Limbs of Vertebrates Vestigial Legs in Snakes
4. Comparative Embryology
Fish
Chicken
5. Molecular Biology
Pig
Human
Current Examples of Evolution by Natural Selection:
It is incorrect to think of evolution by natural selection as a process that takes a long time to see occurring. We can see changes in groups of organisms from generation to generation. Here are some examples of evolution that is occurring around us.
1. Antibiotic Resistant Bacteria
2. Pesticide Resistant Insects
Organisms interacting with each other can improve their fitness. Here are some ecological examples of organisms interacting with each other.
Symbiosis- ______
· Mutualism- Both species benefit from the interaction.
Example:
· Commensalism- One species benefits from the interaction and the other is neither helped nor harmed.
Example:
· Parasitism- One organism lives on or in another organism and harms it.
Example:
Community Interaction / Effect on Organism A / Effect on Organism BCompetition
Predation
Mutualism
Commensalism
Parasitism
When an organism is harmed by an interaction, natural selection favors the survival and reproduction of individuals who have traits that allow that organism to overcome that negative interaction.
Examples of Adaptive Traits that Help Organisms Survive Competition, Predation, or Parasitism: