Unit Ten - Evolution Flashcards
Definition of Evolution
Theory that explains change, alteration & creation of species
(NOT ALL CHANGE IS EVOLUTION)
Definition of Niche
Role or position an organism occupies in its ecosystem
Definition of Species (3)
- Group of organisms
- Can reproduce w/eo
- Produce fertile offspring
Definition of Instant Speciation (2)
- New species arises very rapidly
- Polyploidy in Hybridization of Plants
Definition of Macroevolution (2)
- Large changes
- Over long period oftime
Ex: New species, genera, families
Definition of Microevolution (3)
- Small changes
- In the genetic makeup
- Over a shorter period of time
Ex: Mutations & Natural Selection
Definition of Allele Frequency (4)
- If an allele provides a survival advantage
- Individuals w/ allele reproduce more & pass it on
- Increasing its frequency in the population
Definition of Lamarck’s theory of Evolution (4)
- Evolution is driven by organism’s need to improve
- Acquired traits were exaggerated
- Unuseful traits were diminished
- Offspring inherit traits acquired by parents
(Theory discredited but paved the way for Natural Selection)
Definition of Darwin’s Theory of Evolution (Natural Selection) (4)
- Fittest organisms w/ best adapted traits
- Are favored to survive and reproduce
- Useful traits are naturally “selected” to be more common in population
- Bc organisms w/ best traits survive & reproduce more offspring w/ such traits
What factors contribute to natural selection? (4)
- Overpopulation
- Limited Resources
- Competition for Survival & Reproduction
- Genetic Variation & Diversity
(Enviroment changed and selected favorable variation)
What are two theories accepted for Pace of Evolution?
Gradualism & Punctuated Equilibrium
Definition of Gradualism (2)
- Slow steady change over time
- Change in allele frequencies over millions of years
Definition of Punctuated Equilibrium
Instant Speciation
What are examples of evidence for evolution?
- Fossil Record
- Anatomical Similarities
- Comparative Embryology
- Biochemical Differences
- DNA Hybridization
Definition of Homologous Structures (3)
- Type of Anatomical Similarity
- Same Structure, Different Function
- Demonstrates divergent evolution/common ancestor
Definition of Divergent Evolution (4)
- Two or more species
- Share a Common Ancestor
- Adapt to Different Environments/Niche
- Leads to difference in traits/characteristics
Ex: Darwin’s Finches (Beak Sizes)
Definition of Analogous Structures (3)
- Type of Anatomical Similarity
- Different Structure, Similar Function
- Help demonstrate convergent evolution
Definition of Convergent Evolution (3)
- Unrelated species
- Adapt to Same Environments/Same Niche
- Develop similar traits/characteristics
Definition of Comparative Embryology
Closer 2 organisms are related, the more embryos resemble each other
Definition of Biochemical Differences
Differences of Species on a Molecular Level (AA Sequence)
Definition of Cladogram
Diagram that shows evolutionary relationships among groups
Definition of Evolutionary Classification (3)
- Grouping of Organisms
- Through Pattern of Evolution
- Based on Physical & Microscopic - Level Appearance
Definition of DNA Hybridization (6)
- DNA Pair of Double Strands from 2 Species
- DNA is heated
- DNA Unzips
- DNA Cools
- DNA binds from Species 1 & Species 2
- DNA Hybrid is formed
How does DNA Hybridization provide Evidence for Evolution? (3)
- More closely related two species are
- The more similar their DNA sequences are
- Leading to stronger hybridization
Definition of Chromatography (4)
- Pigment Samples are Extracted
- Samples are applied to a chromatography medium (paper)
- Solvent carries the pigments along the medium
- Pigments separates based on solubility & molecular weight
What are three types of selection? (3)
- Directional Selection
- Stabilizing Selection
- Disruptive Selection
Definition of Directional Selection (3)
- One extreme phenotype in a population is favored in the environment
- Homozygous Triats (Recessive of Domianant)
- Trait gradually becomes more common in population
Definition of Stabilizing Selection (3)
- Intermediate phenotype in a population is favored in the environment
- Heterzygous Traits
- Trait gradually becomes more common in population
Definition of Disruptive Selection (5)
2 Definition, 3 Effects
- Two extreme phenotypes in population are favored
- Homozygous Recessive & Homozygous Dominant
- Leads to split in the population
- Increases genetic diversity
- Potentially gives rise to new species over time
(so different, can no longer interbreed)
Definition of Specitation (4)
- Development of a new species
- Occurs when population of same species live in different environments
- Experiences different selective pressures
- Populations will evolve differently
How do you detect evolution?
Hardy Weinberg Law
Definition of Hardy Weinberg Law (5/4)
Causes
1. No Mutation
2. Random Mating
3. No Migration
4. No Natural Selection
5. Large Population Size (accurate, no sampling error)
Effects
1. Population will be in Equilibrium
2. No Evolution Occurs
3. Frequencies of Alleles are Constant (p and q)
4. Genotype Proportions are Constant (p², 2pq, q²)
What are the two equations associated with the Hardy Weinberg Law? (2)
- p² + 2pq+ q² = 1
- p + q = 1
What does each variable represent in the Hardy - Weinberg Equation?
Allele Frequency: Dominant & Recessive
Genotype: Recessive, Dominant, Heterozygous
Phenotype: Recessive, Dominant, Heterozygous
p = dominant allele frequency
q = recessive allele frequency
q² = recessive genotype
p² = dominant genotype
2pq = heterozygous genotype/phenotype
p² + 2pq = dominant phenotype
q² = recessive phenotype
What is the process in calculating the Hardy - Weinberg Equation? (5)
21 Dragons - 7 have recessive non winged trait
What is the frequency of heterozygote dragons?
- 7/21 = q² = 0.33
- q = √0.33 = 0.58
- p + q = 1, p + 0.58 = 1, p = 0.42
- p² = 0.42² = 0.18
- 2pq = 2 (0.42) (0.58) = 0.49
Why was Lamarck’s Theory wrong? (3)
- Acquired traits do not affect an organism’s DNA
- Modern genetics shows that inheritance occurs through DNA
- Organisms cannot actively change during their lifetime
Best alleles are naturally selected because organisms will survive & reproduce more, increasing allele frequency through inheritance
What are factor changes population sizes and cause sample errors?
Genetic Divergance
What are two types of genetic divergence that can cause sample errors?
Founders effect and Bottleneck effect
Definition of Founders Effect (4)
- Small Population of Species Travel to a New Island
- Results in No Variation (bc there’s only one species)
- Creates sampling error & loss of genes
- Species w/ unwanted gene always mate w/eo, population increase w/ gene
Definition of Bottleneck Effect (3)
- Population Size Decreases
- Because of Natural Disasters, Overhunting & Deforestation
- Creates No Variation & Sampling Error
How does Speciation Occur? (4)
- 2 Population of Same Species are Geographically Separated
- Reproductive Isolation (No mating with other population)
- When Brought Together, Cannot Mate w e/o or produce fertile offspring
- 2 New Species are Now Created
Why do separated species can no longer mate with each other? (5)
- Temporal - Mate at Different Times (Fall, Summer, Diurnal, Nocturnal)
- Ecological - Different Habitats mean Different Traits
- Behavioral - Different Courtship Behaviors
- Anatomical - Physical Differences (Cannot Physically Mate)
- Hybrid Infertility - Hybrids cannot produce fertile offspring
