1. What Is Evolution
- Components
- Evolution
- genetic change over time
- species evolve at different rates
- Gradualism
- Change takes a long time (usually)
- Rate of change can vary within a species
- Speciation
- Common ancestor
- Split into separate groups
- Continued change that results in inability to interbreed
- Infrequent
- Common Ancestry
- Shared traits
- Nested arrangement
- DNA analysis can measure similarity/differences
- Predictions
Common ancestors of birds and reptiles found in the fossil record.
- Natural Selection
- Genetic mutations may improve survival
- “Better” traits are reinforced by reproduction
- The process repeats to spread helpful mutation through the population
- “Natural selection is not a master engineer, but a tinker.” p.11
- The “perfect” mutation may never arise
- 99% of all species are extinct
- “This, by the way, poses an enormous problem for theories of intelligent design. It doesn’t seem so intelligent to design millions of species that are destined to go extinct, and then replace them with other, similar species, most of which will also vanish. ID supporters have never addressed this difficulty.”
- Works on existing features
- Must work with whole organism, which leads to compromise
- Non-selective mechanisms of evolutionary change
- Random changes in proportion of changes
- Evolution
- Evolution is a SCIENTIFIC theory, not someone’s opinion.
- It makes successful predictions
- “In Darwin’s day, the evidence for his theories was compelling but not completely decisive. We can say, then, that evolution was a theory (albeit a strongly supported one) when first proposed by Darwin, and since 1859 has graduated to “facthood” as more and more supporting evidence has piled up. Evolution is still called a “theory,” just like the theory of gravity, but it’s a theory that is also a fact.”
- Predictions can be made and proven
- “Retrodictions” can explain findings
[…] The variety of life is explained by the Theory of Evolution; the evidence for which is overwhelming. […]