Unit 3: Evolution and the Science of Nature Flashcards
What is “evolution” in its simplest form?
Change over time.
How much time have organisms had to change?
3.85 billion years
How old is the Earth?
4.6 billion years
How old did scientists/philosophers think the Earth was in the 1700s?
6,000 years
What did scientists/philosophers believe about species in the 1700s?
That they were all created at once and were unchanged ever since.
Who’s book did Darwin read that helped him in his theory of evolution?
Charles Lyell’s Principles of Geology
What did Lyell’s book say about the Earth?
That gradual, repetitive geological processes shaped the Earth over great spans of time.
What did Lyell’s ideas come to be known as?
The theory of uniformity
How did Lyell’s idea help Darwin’s?
For evolution to work, you need lots of time. Lyell’s ideas made Darwin’s possible.
What do we call the segments of DNA that decide traits?
Genes
What do we call the variations of genes?
Alleles
What units (DNA) are passed down through generations and account for variation?
Alleles
How do alleles related to evolution?
They are the source/cause of random variation between individuals in a population.
What do we call “leftover” organs or etc. in a species?
Vestigial structures
What are the four parts of natural selection discussed in class?
- Organisms have changed over time.
- Organisms share a common ancestor.
- Change is a slow process over many generations.
- The mechanism of evolutionary change was natural selection, acting on random variation.
What are the four steps in random variation leading to natural selection?
- Variation occurs (alleles)
- Survival advantage
- Reproductive advantage
- Allele becomes more frequent in the population
What are the processes the make up the scientific method?
- Observation.
- Hypothesis
- Experimentation
- Analyses
- Theory
What is “observation” in the scientific method?
Observe the phenomenon to be explained
What is “hypothesis” in the scientific method?
A tentative and testable explanation
What is “experiment” in the scientific method?
The testing of the hypothesis, leading to falsification or support, but never “proving”
What is “analysis” in the scientific method?
Evaluate the hypothesis.
What is “theory” in the scientific method?
If a hypothesis hold up to repeated experimentation, it can become a theory; e.g. Newton’s Law of Motion or Cell Theory
What changes and doesn’t change with evolution?
Populations change, not individuals
What is comparative morphology?
Animals that seem different on the outside actually have similar internal structures, suggesting that they share a common ancestor.
What’s the kicker in comparative morphology?
Vestigial structures; i.e. Why would this organ (eg) have even developed if it wasn’t to be used?
What do we call similar structures in comparative morphology?
Homologous structures
What evidence does the fossil record give us?
Shit loads of extinction, showing that life has changed; and the layers show simpler organisms as you go further back in time.
What is the principle of superposition?
Younger fossils lie on top of older fossils
What is the dinosaur boundary called?
The KT Boundary
