Evolution | Study Cards Flashcards
What did Aristotle believe in?
Believed in the Scala of Naturae & Believed that nonliving and living things are “fixed” and do not change over time. He also did not believe that species could go extinct/created.
Describe the Scala of Naturae
- A ladder like classification of nature from simplest –> complex.
- Humans were at the top of ladder and even inorganic matter was included (fire, water, wood, etc)
What did Geoges Cuvier believe in & what was he the founder of?
He believed in the Theory of Catastrphe & he was the founder of Paleontology
What did the Thoery of Catastrophism establish
That extinction was a fact
What 2 things did Jean Baptise believe in?
Principle of Use and Disuse & Inheritance of Accquired Traits
Describe the Principle of Use and Disuse
The more an organism uses a trait the more it grows in that creatures lifetime. The less likely they use it the more likely it will be erased from a generation.
Describe the Inheritance of Acquired Traits
An Organism can pass on to its offspring physical characteristics that the parent accquired through use and disuse
What was Lamarck’s 3 Contributions?
1) All species change over time
2) New Characteristics are passed from one generaton to the next
3) Organisms change in response to their enviroment
What did Charles Darwin do on his voyage?
Observed that plants and animals adapt to their own enviroments
List the 3 influences on Darwin:
1) ) Principles of Geology by Charles Lyell:
2) Personal Observations
3) Essay on the Principle of the Population by T.Malthus
Describe natural selection
A mechanism for evolution
What are the 4 requirements for Natural Selection?
1) Natural Variation
2) Heritability
3) Differential Survival
4) Differential Reproduction
What is Natural Variation?
Individuals within the same species have variation
What is Heritability?
The only traits that can be inherited by offspring are ones that are genetic
What is Differential Survival?
Many offspring do not survive due to low resources
What is Differential Reproduction
All organisms can produce more offspring than the enviroment can support
What is the Malthus Principle
Every generation more offspring than the envroment can support
What was On the Origin of Species by Mean of Natural Selection by Charles Darwin about?
Proposed that all diversity of life is driven by Natural Selection & that all life on Earth is related to and evolved form a common ancestor
Is there a goal for natural selection?
no
Does natural selection create?
No, it only modifies & selects the best traits
List the 5 pieces of evidence for
evolution
1) Fossils
2) Biogeogrpahical
3) Anatomical
4) Similarities in Embryos
5) Biochemical (DNA)
What can you prove with fossils?
You can trace the evolutionary ancestry of an organism
Describe Biogeography in reference to fossils
Provides info on how different groups may have evolved due to the geographic distributions of animals and plants
Describe anatomical in reference to fossils
All vertebrea forelimbs contain the same sets of bones ( Homologous Structures )
Describe the similarties in embroys in reference to fossils
Embryos of different species look & develop similarily
Describe Biochemicals in reference to fossil s
All organisms have a degree of similarity in the DNA base structures
What is MIcroevolution?
Accumulation of small genetic changes within a single population
Microevolution takes place within a short period of time & below a species level
What is a population?
A group of organisms among the same species in the same geographic area
When do you know when a population has evolved?
When there is a change in the allele frequency
What is a species
A group of organisms that can interbreed, reproduce, and share a genetic heritance naturally
What is a gene?
Code for DNA that can code for a characteristic
What is an allele?
Variations of a gene that you get from both parents
What is a genotype?
Genetic makeup of an individual
What is a phenotype?
Physical expression of a gene
What is a gene pool?
Total aggregation of genes in a populatjon at any one time
Derscribe the Hardy - Weinberg Equilibrium
The genetic variation in a populatjon will remain constant from one generation to the next in the absence of disturbing factors
What is the purpose of the Hardy - Weinerbg Equil?
To test whether or not a population is evolving
List the 5 conditions for the Hardy - Weinberg Equil
- 1) No mutatons
- ‘2) No geneflow
- 3) Population is infinetly large
- 4) No Natural Selection
- 5) Random mating
List the 5 causes for Microevolution
1) Genetic Mutation
2) Gene Flow
3) Non- Random mating
4) Genetic Drift
5) Natural selection
Describe Genetic Mutation
Changes in the gene causes a change in allele frequency
What are the 3 options a mutation can be?
lethal, neautral, or beneficial
Describe Gene Flow
When organisms move from one place to another ( the immigrants reproduce and introduce new allleles into the population)
What is non-random mating
When indivduals do not choose their mates randomly and have a preference
What is Assertive MAting?
Individuals tend to mate with those with the same phenotype
What is Sexual Selection
Males compete for their right to reproduce & females choose the males with a particular preference
What is Genetic Drift
Changes in the alllele frequency due to chance & tends to reduce genetic variability
What are the two causes for Genetic Drift?
1) Bottleneck effect
2) Founder Effect
What is the bottleneck effect?
Give an example
An event that prevents the majority of genotypes from entering the next generation
ex) Disaes, starvation, drought
What is the founder effect?
describe it
Few individuals establish a new popualtion & only carry a fraction of alleles
Moving from one place to another where they have never been before
What are the 3 types of natural selection?
1) Directional Selection
2) Stabalizing Selection
3) Disruptive Selection
Describe Directional Selection
When an extreme phenotype is the best fit
Describe Stabalizing Selection
When an intermediate phenotype is the best fit
Describe Disruptive Selection
Two or more extreme phenotypes of better than the intermediate
Which type of natural selection is the least common in nature
Disruptive Selection
What are the 3 implications of conservation
1) Endangered species may experience a decrease in genetic diversity
2) Small number of individuals used for captive breeding programs may not actually represent the entirity of a species genetic diverity
3) Recovered populations may still be less resistant to cope with enviromental changes
