Evolution Flashcards
What is evolution?
A theory used to explain the change in species over time.
What is a niche?
Role an organism occupies in an ecosystem
What is a species?
A group of organisms that can reproduce and produce fertile offspring.
What is instant speciation?
When a new species arises fast or when plants hybridize
What be macroevolution?
Large scale evolutionary changes that happen in a long period of time.
What is microevolution?
Small SCALE changes in genetic makeup in a short period of time.
What is allele frequency in microevolution?
If an allele provides a certain advantage then those characteristics will survive longer as they will get reproduced more which would increase the frequency.
What was Lamarck’s theory of evolution?
Evolution was driven by an organisms desire to improve.
Acquired traits- Traits that were used in an organisms lifetime were exaggerated while traits that were not used diminished.
Inherited characteristics- Offspring are born with the traits achieved by parents.
What about Darwin’s theory of evolution?
Proposed theory of natural selection which is when the fittest organisms survive and reproduce.
What factors contributed to natural selection?
Overpopulation
Limited resources-Competition
Environmental change
Two theories accepted for pace of evolution?
Gradualism and punctuated equilibrium
What is gradualism?
SLOW and STEADY change in time AND changes in ALLELES frequencies over millions of years.
What is punctuated equilibrium?
Rapid and instant speciation
What are examples of evidence for evolution?
Fossil record,
anatomical similarities,
comparative embryology,
biochemical differences and DNA hybridization.
What are homologous structures?
Same structure but a different function and it helps demonstrate divergent evolution.
What is divergent evolution?
Two or more related species that share a common ancestor but adapt to different environments which leads to distinct traits.
What are analogous structures?
Different structure same function and it helps explain convergent evolution.
What is convergent evolution?
Unrelated species that adapt to same environment and develop similar characteristics.
What is comparative embryology?
The study of embyros to compare and contrast their similarities to look for common ancestors.
What are biochemical differences?
Differences in species on a molecular level like Amino Acid differences.
What be a cladogram?
A diagram that shows evolutionary relationships among groups.
What is DNA hybridization?
A powerful tool used by scientists to help classify different organisms from each other. First they unzip the DNA and mix with other DNA and see if it sticks or fits in like a puzzle.
The evolutionary process can work to…
select different phenotypes in a population
What are the different types of selection.
Directional Selection
Stabilizing Selection
Disruptive Selection
What is directional selection?
One extreme phenotype is favored in the environment and gradually becomes more common due to natural selection. Homozygous
What is Stabilizing Selection?
The intermediate phenotype in a population is favored in the environment. Heterozygous
What is disruptive Selection?
Two extreme phenotypes in a population are favored in the environment.
What is the definition of speciation?
If populations of the same species develop different selective pressures, these populations will evolve differently from one another. The result IS A NEW SPECIES.
What is the Hardy-Weinberg law?
It is a tool used to measure evolutionary change over thousands of years (it also has a formula to it)
A sexually reproducing population will be equilibrium if five conditions are met. SO WHAT ARE THEY?
- Random Mating-No selection, no preference
- No mutations-No change in DNA
- No gene flow-movements of genes through immigration or emigration
- Large populations
- NO NATURAL SELECTION
What about the Hardy - Weinberg formula?
It is a mathematical expression to calculate genotypes, phenotypes and gene frequency.
What are those two equations?
p² + 2pq+ q² = 1
p + q = 1
What do the letters represent?
p = dominant allele frequency
q = recessive allele frequency
q² = recessive genotype
p² = dominant genotype
2pq = heterozygous genotype
p² + 2pq = dominant phenotype
q² = recessive phenotype
