evolution Flashcards
- Darwin’s Theory of Natural Selection and its conditions
- Darwin’s Theory of Natural Selection and its conditions
a. Limited natural resources
b. Excess population
c. Heritable variations in populations
- Sources of variations
- Sources of variations
a. Mutations
b. Recombination
c. Conjugation
d. Random fertilization
e. Assortment of Chromosomes
- Evidence for evolution
Examples:
- Evidence for evolution
a. Fossils: Imprints of remnants of organisms (ex. transitional whale fossils)
b. Biogeography: Study of geographical distribution of organisms and species (ex. whale valley)
c. Comparative Anatomy: Comparing organisms’ bodies and how they use them (ex. homologous structures, such as the similarities of the whale and wolf’s spine and skull)
d. Comparative Embryology: Comparing organisms’ embryos (ex. humans and other mammals have embryos with gills)
e. Molecular Biology: Study of genetics and DNA (ex. humans and apes have 98% same DNA)
- Advantages, disadvantages, examples, and information on the various types of selection and reproduction
The First 1
a. Sexual
i. Information: Females/investors get choice while the males have competition
ii. Advantages: Variation, the best defense against rapidly evolving enemies
iii. Disadvantages: Takes time and energy
iv. Examples: Conjugations in bacteria, sexually reproducing animals (humans, menoes, etc.)
- Advantages, disadvantages, examples, and information on the various types of selection and reproduction
The Second 1
b. Asexual
i. Information: Clones are made with the exact set of DNA as the parents (unless a mutation occurs)
ii. Advantages: Needs one organism, takes less time
iii. Disadvantages: No variation
iv. Examples: Yeast budding, lesbian lizards, certain menoes, bacteria
- Advantages, disadvantages, examples, and information on the various types of selection and reproduction
Third 1
c. Artificial
i. Information: Selection not caused by nature, unnatural choice of genotypes and phenotypes
ii. Advantages: Can have more variation, choice
iii. Disadvantages: Can have less variation
iv. Examples: Selective breeding, arranged marriages, designer babies.
- The three outcomes of natural selection
- The three outcomes of natural selection
a. Directional: When there is a change in the mean; when only one type of phenotype is favored
b. Stabilizing: When variation decreases; phenotypes are more similar and uniform
c. Disruptive: When extreme phenotypes are favored, there is less transitive phenotype
- Mechanisms of microevolution
examples a,b
- Mechanisms of microevolution
a. Natural Selection: Environmental pressures force variations with advantages to survive better and reproduce
b. Gene Flow: Exchange of genotypes as populations move to different areas and reproduce with the local populations
- Mechanisms of microevolution
the remainder of the examples
d. Genetic Drift: A change in the gene pool of a small population due to chance
i. Bottleneck: Genetic drift due to a drastic reduction in population size
ii. Founder Effect: Genetic drift in a new colony
Allopatric
a. Allopatric: Geographic speciation caused by an isolated population and the Founder Effect. Physical separation that may begin with gene flow and/or genetic drift and continues by natural selection. The variation causes speciation as the species becomes different and are unable to mate with the original species (ex. flies in Hawaii)
b. Sympatric:
b. Sympatric: Not physically separated, but conditional reproduction. Species are in the same location, but habits force the breeding choice and so species don’t intermix, which causes speciation (ex. big fish swim to the bottom of a lake to eat the plants, the small fish prefer to eat the seeds at the top of the lake)
- The differences in the ideas of Darwin and Lamarck on evolution
- The differences in the ideas of Darwin and Lamarck on evolution
a. Darwin: Believed in natural selection, random mutations, and a change over generations and time.
b. Lamarck: Believed that by using or not using body parts, an individual develops characteristics that it can pass to its offspring; inheritance of acquired characteristics.
Cladogram versus Dichotomous KEyy
a. Cladogram: Chart showing evolutionary relationships between species through synapomorphies and automorphies
d. Dichotomous Keys: A table or flowchart that classifies species through synapomorphies and automorphies
Synamoprhies and Automorphies
b. Synapomorphies: Similar features shared among ancestral species and their descendants
c. Automorphies: Unique features that are not shared among similar species, but only found with one species
Evolution : And Natural Selection
- Definitions of essential unit vocabulary.
a. Evolution: Genetic change in a population or species over generations
b. Natural Selection: Environmental pressures that select against least adapted organisms, causing competition and variation.
Population and Gene Pool
c. Population: A group of interacting individuals belonging to one species and living in the same geographic area at the same time.
d. Gene Pool: All the alleles in all the individuals making up a population
Microevolution
Macroevolution
e. Microevolution: A change in a population’s gene pool over a succession of generations; evolutionary changes in a species over relatively brief periods of geologic time.
f. Macroevolution: Evolutionary change on a grand scale encompassing the origin of new taxonomic groups, evolutionary trends, adaptive radiation, and mass extinction
adaptation and Cladogram
g. Adaptation: Inherited characteristics that enhances an organism’s ability to survive and reproduce in a particular environment
h. Cladogram: Chart showing the changes in a species over time
Variation and Speciation
i. Variation: Different combinations of alleles in populations and individuals
j. Speciation: Creation of new species
Hardy-Weingburg
- Population Genetics and Evolution Lab - learning the Hardy-Weinberg principle of genetic equilibrium and studying the relationship between evolution and changes in allele frequency.
conditions for the Hardy-Weinburg
a. Estimating allele frequencies for a specific trait
b. Hardy-Weinberg population conditions
the 5 steps needed to meet the H-W standards
- The population is very large, the effects of chance on changes in allele frequency is thereby greatly reduced.
- individulas show no mating preference, entirely random
- no mutations
- no emigration or immigration of individuals
- No selection
other H-W problems
The principal that the shuffling of genes, that occurs during sexual reproduction by itself, cannot change the overall genetic make up of a population
• Individuals/Genotypes:
- AA (p^2)
- Aa (2pq)
- aa (q^2)
• Allele’s only:
- q (frequency of the a allele)
- p (frequency of the A allele)
The Variation LAb
- **To show the variation between the individuals in a species**
- Yes, there is variation within the species but usually there are no extreme differences
- Each variation has its own positives and negatives
Population Genetics and Evolution Lab
- **To show the relationships and changes in allele frequency**
- Each 5 Hardy-Weinberg assumption must be met
- When there is no selection against a species, the individuals and alleles stay about the same
CHange through Natural Selection LAb
- **To show how predation may cause an adaptive change in the prey/predation population**
- (Bean Lab)
- Predators and Prey best adapted to the surrounding environment are more likely to survive. Example: the spoon and lentil bean were the best adapted to the lighter carpet’s environment.
- GRAPHS shown below
cladogram
- **Constructing a cladogram**
- Cladogram: A dichotomous phylogenic tree that branches repeatedly, suggesting a classification of organisms based on the time sequence in which evolutionary branches arise.
- Purpose of a cladogram: to show the shared and unique features of organisms over time.
Automorphie: None of the organisms before this species have a certain feature, but the ones after it do.
Synamorphie: Unique to the species.
Dichotomous key
- Dichotomous Key: Tools used in classification; starts off being organized so that there are 2 choices presented, and eventually a specific organism is identified.
- 2 ways of organizing a dichotomous key:
• Branching Dichotomous Key
• Numbered Dichotomous Key - (School Field Trip – Finding Plants)
