EVOLUTION

UNIT 1: What is the nature of science? Understand the process of science. Distinguish between scientific and everyday meanings of key words— theory, hypothesis, law, fact—and use in context. Recognize the importance of inference and interpretation. Understand that explanations often change as new evidence is found.

“Science is an equal opportunity venture with clearly defined processes” Science: built on principle that the same natural laws we observe today have been operating over space and time. Scientific Inquiry: begins with an observation that leads to a question. Careful Observations: foundation of scientific inquiry.

Clearing up Misconceptions

SCIENCE A way of knowing about the natural world. Scientific explanations are based on observation and facts that can be confirmed or disproved by other scientists using accepted scientific techniques

LAW Description of how a natural phenomenon will occur under certain circumstances. Kepler’s Law of Planetary Motion describes the relationship between the time it takes a planet to go around the Sun and the planet’s distance from the Sun. Our common definition:

FACT A natural phenomenon repeatedly confirmed by observation. It takes Venus 225 days to go around the Sun.

HYPOTHESIS A possible and testable statement about a natural phenomenon. Newton proposed that the force of gravity between two objects depends on the distance between the objects.

THEORY A well-substantiated explanation of some aspect of the natural world that typically incorporates many confirmed observations, laws, and successfully verified hypotheses. Industrial Melanism: the darkness—of the skin, feathers, or fur—acquired by a population of animals living in an industrial region where the environment is soot- darkened. Our common definition:

Unit 2: Who was Charles Darwin? “From my early youth I have had the strongest desire to understand or explain whatever I observed--” Charles Darwin

Darwin Observations about diversity and distribution of species spurred his thinking for On the Origin of Species by Means of Natural Selection.

His Revolutionary Theory: NATURAL SELECTION 1. Populations have variations. 2. Some variations are favorable. 3. More offspring are produced than survive. 4. End result: Population will change over time. The more advantageous trait, becomes more common in the population.

DARWIN hypothesized that… Studying ARTIFICIAL SELECTION of animals would offer clues to the understanding how new species arise in the natural world.

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UNIT 3: What is the Evidence for Evolution? Three Types – Fossil – Anatomical – Molecular

Fossil Evidence Transitional Fossils – Ambulocetus: walking whales that could also swim. – Rodhocetus: mostly aquatic, but could walk on land.

Anatomical Evidence Homologous Structures: characteristics which are shared by related species because they have been inherited in some way from a common ancestor.

Molecular Evidence Comparing base and amino acid sequences of the same proteins from different animals.

UNIT 4: How Does Evolution Work? Primary Mechanism of Evolution: Natural Selection Recombination of chromosomes during meiosis, and mutations cause variation in individuals. These variations can enable some organisms to survive environmental changes, reproduce, and pass those genes to their offspring.

How is this an example of Natural Selection?

Another Mechanism of Evolution: Founder Effect A small population with limited diversity founds a new population in a new location. They change over time and become different from the source population. FINCHES- Blown to Galapagos from Equador; these finches founded a new population on the Galapagos.

UNIT 5: Why Does Evolution Matter Now? Pathogens Bioengineered Food Pesticide-Resistant Insects Habitat Destruction and Extinction

Pathogens Our misuse and overuse of antibiotics has bred drug resistant strains of bacteria, such as Staph, Strep, and TB. HIV: our understanding of the evolution of pathogens has helped doctors prolong the lives of individuals with HIV.

SIV to HIV

Bioengineered Food Bug-resistant corn has been genetically engineered. These genes have spread into natural environments…what are the long-term effects?

Pesticide-Resistant Insects During the last 50 years, 500 species of insects and mites have become resistant to pesticides.

Habitat Destruction and Extinction Habitat Destruction = Population reduction Smaller populations = Less genetic diversity Less genetic diversity = Less of a chance that organisms will survive changes in ecosystems.