Lecture 2 - Origin of Species Flashcards
Exam 1
What is descent with modification?
Darwin defines it using natural selection. Species accumulate differences from their ancestors as they adapt to different environments over many generations.
Why is evolution a theory and not a law?
Evolution is predictive and strongly supported by observations and experiments. Although the basic tenants remain robust, it is being refined as new evidence emerges.
What are the 3 key observations about life that Darwin studied?
- organisms are well suited for their environments
- The many shared characteristics of life
- The rich diversity of life
How is evolution a pattern?
There is data that shows how life has evolved over time.
How is evolution a process?
There a mechanisms that cause the observed pattern of change.
Who is Aristotle?
He is a philosopher who came up with the foundational concepts of evolution. He believed species were fixed in their phenotypes and on a scale of natural hierarchy based on complexity.
Who is Hutton?
He is a geologist who proposed gradualism, the concept that the Earth is old and shaped by small, slow changes caused by natural events.
Who is Malthus?
He is an economist that observed that all resources are limited which therefore limits population growth.
Who is Lamarck?
He figured out that traits are not fixed, but through the incorrect concept of the inheritance of acquired traits. He did not provide a mechanism for evolution leading to backlash about his ideas.
What is the inheritance of acquired traits?
Organisms increase in complexity by inheriting traits that are used and improve a population and not inheriting traits that are disused.
Who is Cuvier?
He is a paleontologist that used fossils as evidence of extinction which challenges the idea of species being fixed.
Who is Lyell?
He is a geologist that reinforced the idea that slow processes shaped the Earth, but discovers that they have been uniform over time.
How did Darwin refute Lamarck’s ideas?
He used artificial selection to show that changes in the frequency of traits in a population were observed between not within populations.
What are the 4 tenets of natural selection?
- Many offspring are produced, not all survive
- Traits vary among individuals in a population and may be heritable
- Some heritable traits give individuals an advantage in their environment
- Advantageous traits, giving higher fitness, become more common
