Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
51 Cards in this Set
- Front
- Back
Evidence of macroevolution? |
1) Evidence that species are related 2) Evidence that species and species diversity has changed over time |
|
What evidence do we have that species are related? |
1) Geographic proximity of similar, non-interbreeding species suggests relatedness 2) Homology in traits |
|
What evidence do we have that species and species diversity has changed over time? |
Fossil Record and Vestigal Traits |
|
What are the major evolutionary trends we've observed? |
1) Increase in multicellularity 2) Increase in complexity 3) Increase in ways to capture energy 4) Increase in ways to deal with the environment 5) Increase in diversity (snowball effect) |
|
Define Evolution |
Heritable change in a population over time |
|
Whats the biological hierarchy? |
Organisms - Populations - Communities - Ecosystems - Biosphere |
|
What was Aristotles great chain of being? |
Pre-darwinian idea that all species are organized into a sequence based on increases size and complexity with humans at the top |
|
How was variation understoofdbefore darwin? |
Variation between individuals is unimportant or misleading |
|
Who stated the first formal evolutionary theory? What was stated? |
Jean-Baptiste de Lamarck who stated that species changed through time via acquired characteristics as a result of environmental pressures |
|
What is required for natural selection? |
1) Trait variation in a population 2) Heritability 3) Differential Survival 4) Differential Reproduction |
|
Define adaptation |
Acquired heritable trait that increases relative fitness |
|
Define Contrivance |
Adaptation that exists as a result of the modification of the previous adaptation in an ancestor ex: A pandas thumb |
|
Define atavism |
Vestigal trait that only a few species have |
|
Define exaptation/pre-adaptation |
trait that was adaptive under a prior set of conditions that becomes a contrivance under the new conditions |
|
What can shift gene allele frequency? |
1) Natural Selection 2) Random Genetic Drift 3) Gene Flow 4) Mutation |
|
Define genome |
All the DNA inlcuding noncoding stretches |
|
Define gene pool |
All the alleles of all the genes within a pop. |
|
Define genotype |
All the alleles of all the genes within an individual |
|
How is Klinefleter's syndrome an example of phenotypic plasticity? |
XXY individuals are male but have a variety of sypmtoms ranging form slight to severe |
|
What are the areas of variation during meiosis? |
1) Non-sister chromatids crossover 2) Tetrads line up in meiosis 1 and their orientation determines if the daughter cell gets all the paternal/maternal/combination of genes 3) In meiosis II, sister chromatids seperate into gametes |
|
How much variation is possible with and without cross over? |
With cross-over: Infinite because crossover can occur anywhere along the chromosome Without cross-over: 2^n where n = haploid # chromosomes |
|
Give an example of nondisjunction and it's health implications |
Trisomy leads to down syndrome |
|
What are the sources of variation in asexual organisms? |
Transformation - with plasmids Transduction - integration of viral DNA Conjugation - Create a tube between two cells for plasmid transfer |
|
Who explained how traits are inherited? |
Not Darwin for sure! Austrian monk Gregor Mendel |
|
What is mendel's first law and how did he prove it? |
Law of Segregation: Alleles pass without dilution into gametes Found this while investigating if genes blend Found 3:1 ratio of round to wrinkled in F2 peas |
|
What is mendel's second law and how did he prove it? |
Law of Independent Assortment: Alleles of a particular genes are pass too offspring independently of other genes 9:3:3:1 ratio of peas in F2 plants comparing seed color and shape |
|
What are the patterns of inheritence? |
1) Autosomal Dominant 2) Autosomal Recessive 3) Sex-linked |
|
What were the issues with mendel's work? |
1) Incomplete Dominance 2) Codominance 3) Polygenic Effects 4) Pleiotropic Effects - single 5) Environmental effects 6) Epigenetic effects |
|
How are incomplete and codominance different? |
1) Incomplete dominance is the expression of an intermediate phenotype sorta like blending 2) Codominance is when both genotypes are expressed as a combination of both not as a diltuion |
|
How do polygenic and pleiotropic effects differ? |
Polygenic: 1 trait is affected by many genes additively Pleiotropic: 1 genes affects many traits |
|
What are tandem repeats and how are they a source of variation? |
Section of repeating code in DNA that allows for unequal crossover due to DNA connecting incorrectly |
|
Natural selection acts at the _____ level, but evolution is measured at the _____ level |
Individual, population |
|
Hardy-Weinberg formula for 2 alleles in a population |
(R*R) + (r*R) + (R*r) + (r*r) = 1.0 R^2 + 2Rr + r^2 = 1.0 p + q = 1.0 |
|
What's the logic behind the hardy weinberg model? |
Starting with a monohybrid cross of 2 purebreds, the F2 will have 2 phenotypes and 3 genotypes (3:1) F2 R r R RR Rr r rR rr |
|
What are the assumptions of the hardy weinberg? |
1) p and q are always the same generation after generation 2) No mutation 3) No flow 4) Infinite pop. size 5) No natural selection 6) Random mating |
|
What ways can a pop. change that would violate the Hardy-wenberg |
Bottlenecks Gene Drift Gene Flow Non-random mating |
|
When does genetic drift have the largest impact? |
Small populations aka bottlenecks and founder effect |
|
What are examples of non-random mating? |
Assortative mating Inbreeding Sexual Selection Female choice Male-Male competition |
|
Whats the convention for naming a genus and species? Who set this up? |
Genus then species All italicized Capitalize Genus, lowercase species Thanks Carolus Linnaeus |
|
What are the 5 kingdoms |
Monera, Protists, Plantae, Fungi, and Animalis |
|
What are the 3 diff. criteria for designating species? |
Biological Species Concept Morphospecies Concept Phylogenetic Species Concept |
|
What are the isolation mechanisms that gives rise to speciation according to the biological species concept? |
Prezygotic and Postzygotic isolation |
|
Whats the difference between pre and post zygotic isolation mechanisms? |
Prezygotic: Prevention of individuals from mating Postzygotic: offspring of individuals do not survive or are sterile |
|
What the problems with the biological species concept |
Problematic for distinguishing species in the fossil record and for organisms whose populations do not overlap |
|
What's a clad? |
Group of species that share recently derived characteristics |
|
Whats the difference between a mono and paraphyletic group |
Monophyletic: Ancestor and all its decendents Paraphyletic: Ancestor and not all its descendents Useful for clarifying the loss of evolved traits and convergence |
|
How is the dusky seaside sparrow case evidence for the use of the phylogentic species concept over the others |
Upon phylogenetic analysis, researchers realized that they had been misled by the mophospecies and biological definitions of the sparrow and accidentally bred the wrong birds together |
|
How can populations speciate? |
Via allopatric and sympatric speciation |
|
How do sympatric and allopatric speciation vary geographically? |
Allopatric speciation occurs when subpopulations are seperated by a physical barrier Sympatric occurs when there is no barrier |
|
What happens when newly formed species come back into contact? |
1) Reinforcement of species 2) Hybrid zones 3) New species through hybridization |
|
Define assortative mating |
Individuals are likely to mate with individuals similar to themselves |