Exam 1 CH 1-7 Flashcards
(46 cards)
Describe the evolution of drug resistance
- the rate of mutation in bacteria is very slow
- as bacteria evolve (conjugation) there are gains and losses of the genetic material
- drug resistance occurs when there is high amounts of the drug being used and the treatment isn’t finished because the bacteria evolve to have these resistance to these type of antibiotics
What does it mean by proximate causes in relation to biological phenomena?
Example: song of a male marsh warbler
Mechanism or structure
Example: brain structure in the 2 songs
What does it mean by ultimate causes of biological phenomena?
Example: song of a male marsh warbler
Evolutionary drivers and history of events
Example: natural selection (reproductive success)
What is Carolus Linnaeus known for?
Linnaeus is known for the binomial system in assigning scientifc names to species
(father of taxonomy)
Apiaceae Daucus carota
Label it
Apiaceae (Family)
- Daucus* (Genus)
- Daucus carota* (Species)
- carota* (specific epithet)
What are the 5 components of Darwin’s theory of evolution?
- Evolution (not the first to come up with the theory)
- Common descent (common ancestor of all species)
- Gradualism (evolved by small steps over several generations)
- Populational change (proportions of variants within a population)
- Natural selection (he came up with the mechanism for evolution/accounts for adaptations-fitness features)
What is the difference between a theory and a hypothesis?
How are phylogenetic trees inferred?
By characters or traits
- The fact that they are genetically based and can be passed on to offspring (heritable
- Character states: petal number (3, 4, 5)
- Homology (homologous characters): states shared by two or more species
What are the three main types of characters or traits from how a phylogenetic tree is inferred?
- Homologous characters
- Orthologous genes (genes that diverge from a common ancestral gene)
- Paralogous genes (genes that originate from an ancestral gene duplication)
Is a phylogenetic tree a hypothesis or a theory?
Hypothesis
What are the patterns of evolutions of characters?
- Modified from pre-existing features
- Different rates (mosaic evolution)
- Gradualism
- Homoplasy is common (convergent evolution)
- Describe patterns of diversification (adaptive radiation)
What is artificial selection?
Select indvidiuals with the most desirable trait and cross-breed to produce the next generation. If the trait is genetically-based and passed down to progeny, the next generation will have a higher proportion of individuals with the trait.
What is natural selection?
Differential survival/reproductive success (higher fitness) of individuals with that feature in a population
What is an adaptation?
Feature that becomes selective advantage in a population
After several generations, the feature becomes prevalent in the progeny over time
Why doesn’t natural selection selectively pick out the beneficial features in a population as compared to the deleterious mutations?
- Natural selection is not an active power (not forethought)
- Describes the way of the process (metaphorical expressions)
- For statistical differences in reproductive success
What are Darwin’s 4 postuales of natural selection?
- Individuals within species are variable
- Some of these variations are passed on to offspring
- In every generation, more offspring are produced than can survive
- The survival and reproduction of individuals are not random; the indviduals who survive and go on to reproduce the most offspring are those with the most favorable variations, and they are naturally selected
How to test hypothesis of adaptation?
Why did a lineage become “fixed” for a derived character state and lost the ancestral state?
A valid hypothesis must include: specifies a trait and a biological function (must be specific)
What is an exaptation?
A trait that originally evolved for one function but was later co-opted for a different function
Label where would selective regime be and adaptation
Also, are the phylogeny and placement of selective regime and adaptation consistent with our hypothesis?
Dorsal scapula speciation mark (adaptation)
Selective regime (hunting for food/throwing ability) to humans only
No, because improved throwing ability (selective regime) evolved after dorsal scapulae adapation, which makes this an exaptation.
*Adaptation evolves after selective regime
How to infer the adaptive significance?
By the use of the comparative method
-determine ecological or other selective factor with which it is correlated
What is the comparative method and what is it mainly used for?
Comparing sets of species to pose or test hypotheses on adaptation and other evolutionary phenomena
-convergent evolution
What is an evolutionary trade-off?
The existence of both a fitness benefit and a fitness cost of a mutation or character state
Why did a certain trait evolves?
The adaptation is better than the ancestral character
What would a trait not be an adaptation?
Consequence of physics or chemistry (red blood cells)
-consequential feature may serve a function
Evolved by other mechanims (genetic drift or gene flow)
May have evolved because of genetic correlations
-genetic linkage and pleiotropy
