Biology Midterm 3 Flashcards
Three Pillars of Evolutionary Thought
- Fixity of Species
- Hierarchical Organization
- Natural Theology`
Fixity of Species
Species do not change over time
Hierarchical Organization
Species fall into natural groups
Natural Theology
All creation due to activities of Christian God
Uniformitarianism
Whatever happened in the past is still happening now
Components of Natural Selection
- Variation within a species
- Inheritance of variability
- Struggle for Existence
Ultimate Goal of Life
Maximum reproduction and successful progeny
Evidences of Natural Selection
- Artificial Selection
- Comparative Anatomy
- Embryology
- Geographic Distribution
- Progression of Fossil Forms
- NeoDarwinian Synthesis
Artificial Selection
Humans select traits and modify through reproduction
Comparative Anatomy
Compare the forelimbs of vertebrates
Embryology
Look at stages of embryo development to see common ancestry
Geographic Distribution
Separated by geography
NeoDarwinian Synthesis
More successful genotype is the more successful offspring
Population
Individuals of same species living in a given geographical area
Gene Pool
All of the genes of a population
Allele Frequency
Relative proportion of each allele in the population
Hardy Weinberg Principle
All frequencies remain unchanged.
No mutations or gene flow.
Very large population and completely random mating.
Gene Flow
Movement of alleles to or from another population
Genetic Drift
Some random event that removes some alleles from a small population
Bottleneck
Population decreases due to an event
Founder Effect
Small portions of a population “founds” new area
Competition
Struggle for scarce resources
Sexual Selection
Selection that acts on traits that are used to acquire a mate
Effects of Natural Selection on Populations
- Directional
- Stabilizing
- Disruptive