Evolution Exam1 Flashcards

Terms Definitions
common ancestor
Recombinational Speciation
(ie. sunflower)
Genome becomes stable or fixed.
Identify blocks of parental genome.
Sections of Chromosomes non-random... natural selection
-adaptive evolution and evological divergence
gene duplication, two hands
Fixed vs. Lost alleles
original source of allelesmicro
Post-translational modification
Permanent modifications: proteolytic processing, disulfide bond formation, addition of prosthetic groups, carbohydrates or lipids.Reversible modifications: phosphorylation, acetylation, methylation.
descriptive statement made from experiments, observations, and studies (describe phenomenons)
Experiments in support of Evolution
How much variation?
Summar Statistics:
1)halotype diversity (ie. haploid genotypes: mitochondria)
2)allelic diversity (expected heterozygosity)
-look at heterozygosity (h) to measure variation
-hexp= 1sumX^2 (x=frequency of each allele at one locus)
Linkage disequilibrium decays in natural pops by process of
The observable or testable appearance of an organism that may or may not reflect a particular genotype due to the variable expression of dominant and recessive alleles.
Eukaryotic Cell
• Organelles with membranes– specialized factories• Nucleus• Cytoskeleton– Support for cell– Changes in shape– Mitosis (distribution of daughter chromosomes)– Move materials within cell– Sets the stage for structures used for movement
Genetic Drifts
unpredictacble fluctuations in gene frequencies from one population to next because of a populations finite size
Survival of the Fittest
see Natural Selection
artificial selection
-Breeding certain advantageous or desired genes-Ex.: Dog breeding
molecular clocks
using predictable changes in DNA(mutation rates) to establish time-lines
directional selection
stabilizing, disruptive, directional - three types discussed earlier
Sympatric Speciation
Populations are not physically isolated, but are reproductively isolated
-divergent selection (eg Killer Whales)
Mechanisms of Divergence
-What factors cause populations to diverge?
-genetic drift (bottlenecks/colonization)
-sexual selection
-natural selection
Homologous Structure
Having similar structure and anatomical position (but not necessarily the same function) in different organisms suggesting a common ancestry or evolutionary origin (e.g. wings of bats and arms of humans are homologous).
Deleterious mutations are maintained at mutation-selection balance by the action of
purifying selection
Most fossils are found in
sedimentary rock
Portions of DNA molecules that direct the synthesis of specific proteins
selective breeding
breed organisms exhibiting the "best" traits
Postzygotic Isolation
When hybrids are inviable or sterile.

Such as male ligers.
Macroevolution is a scale of analysis of evolution in separated gene pools.[1] Macroevolutionary studies focus on change that occurs at or above the level of species, in contrast with microevolution,[2] which refers to smaller evolutionary changes (typically described as changes in allele frequencies) within a species or population.
Condition in which two populations of a species are seperated so that they cannot interbreed.
Founder Effect
similar to bottleneck; a small population of species moves to a new habitat; there is reduced genetic diversity in the new population and a rapid change in allele frequency for high potential of divergence and speciation (ex. human colonization)
Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this?a. artificial selectionb. disruptive selectionc. stabilizing selectiond. sexual s
small differences between members of a species due to reshuffling of genes during sexual reproduction or mutations
Phylogenetic tree
-A diagram that portrays the evolutionary relatedness of speciesNodes:Tips:Root:Outgroup:Ingroup:Sister taxa:Polytomy:
Measuring variation
-to measure variation, need to determine genotypes (phenotypes, DNA)
Parallel Evolution
the development of similarities in species that are related but separated (geographically) due to similar biomes with similar other species surrounding them
Modern Synthesis
Mutation or genetic drift introduce variation
Subject to selection
Resulting in adaptive changes in phenotype
Eventually resulting in organismal diversity
Homologous structures
structures that have diffrent mature forms in diffrent organisms but developed from the same embyonic tissues
Hereditary changes in groups of living organisma over time
What did Charles Darwin study at Cambridge University?
the order in which sedimentary strata are superposed one above another.
Refers to a chromosome pair that bears different alleles for a single gene.
change is the result of a slow, cumulative, continuous process
Recognition Species Concept
"The most inclusive population of biparental organisms which share a common fertilization system"Focuses on processes that act to preserve a common fertilization system.Stresses positive features of species that enable the two sexes to recognize each other.The focus is on mate-recognition systems: courtship displays, timing, habitat selection pheromones, etc.
Sexual Selection
Females depend on quality; males on quantity
population fragmentation
reduction of a single population into several smaller populations
episodic extinctions
period of extinction of some organisms in different regions at different times
Evolutionary reversal
constitute a return from an "advanced" or derived character state to a more "primitive" or ancestral state
Post-zygotic isolation
The zygote formed is not viable-hybrid viability: zygote fails to survive-hybrid sterility: offspring is sterile
genetic drift
change in relative frequency in which allele occurs in a population due to random sampling and chance
A feature that may have evolved not because it conferred an adaptive advantage, but because it was correlated with another feature that did have an adaptive advantage, is an example of:
What are the three different reproductive isolations?
Behavioral, Geographic, Temporal
Gene Pool
Sum total of allels in the reproductive gametes of a population
Mendel is associated with the evolutionary concept of
use and disuse
Fossil Record
the collection of fossils recorded in rock layers over time
adaptive radiation
single species in area - population - high competition - population fragments into different habitats
Name a component of the fossil record.
Ex.: dinosaur footprints
What are the two descriptions of variance and how are they different?
sigma-squared and s-squared.Sigma-squared is used when you measure every individual in a population and s-squared is used when you are just measuring a sample of the population.
what do niches cause
less competition thus letting the species thrive
Possible Formations of primordial soup
1-reducing atmosphere: due to accumulation of rich ammonia, hydrogen, methane atmosphere, formed organic molecules in oceans2-Extraterrestrial: organic compounds delivered via meteorite/astroids3-Deep Sea Vents: volcanoes underwater forming ammonia and hydrogen sulfide
Why do we need variation?
Human susceptibility to flatworm infection influenced by single gene (SM1)
-pedigree analysis
-2 codominant alleles S and R
SS = susceptible
RR = resistant
SR = intermediate
*more variation means better ability to adapt
*maintained by mutation, selection, ec
selection will select for non-synonymous mutations in smaller organisms due to shorter generation time and other factors
What is Artificial Selection?
Human selected traits, mainly in plants
to change to fit in your environment ( a new school)
Narrow-sense heritability estimates the proportion of the total phenotypic variance
Natural Selection:Inference 3
overtime in a population there will be a gradual increase in favorable characteristics for individuals to survive and reproduce.
survival the fittest
(natural selection)
process by which individuals that are better suited in their enviroment survive and reproduce most successfully
Ne: The effective population size
Census Population Size
Ne:The size of the theorectical (ideal) population that producesa the level of genetic drift observed in a real population
Census Population: The actual recorded population size based on the level of genetic drift
If you were a biologist studyng the type of natural selection where an extreme phenotype is favored and the distribution curve shifts toward that phenotype, you would be studying which of the following?
A. disruptive selection
B. directional selection
B. directional selection
Lamarack, Mendel, Wallace, Darwin
Lamarack (1809) - argued that species change into new species
-argued that acquired traits were inherited
-this is not true... don't inherit muscles, dyed hair, etc
Mendel- work was lost temporarily
Wallace and Darwin
-evolution (descent with modification) and natural selection
-evolution is not progressive (newer not better)
-evolution is not 1-dimensional
What is the bottleneck effect?
When something happens (ex. natural disaster) which decimates population, not caused by natural selection
no evolution occurs when
there is no change in allele frequencies between generations
Who described some of Darwin's fossils? What was his and Darwin's relationship?
He was willing to help Darwin in the beginning but eventually became an enemy of Darwin's.
Natural selection can best be defined as the:
A. survival of the biggest and strongest organisms in a population
B. elimination of the smallest organisms
C. survival and reproduction of the organisms that occupy the largest area
D. survival and reprod
D. survival and reproduction of the organisms that are genetically best adapted to area
Who was Tomas Malthus?
An economist who said that if the population kept going unchecked, there would not be enough living space and food.
Carbon 14 (14C) Dating
looks at decay of carbon isotopes to figure out age of fossils; only useful for ages 50-70Kyrs.
Evolutionary processes involved in the speciation process? II
2) Sexual selection: genes that cause sterility evolve faster than genes that cause viability. This could be a consequence of sexually antagonistic genes. Rapid and continuous evolution of these loci could be "engine of speciation"
Describe RGD, Founder Effect, and Genetic Bottleneck
RGD: Alleles that establish the next generation are assumed to be a random sample from parental gene but are really not due to sampling bias as well as random drift of the frequency of a given allele
Founder Effect: a genetic drift like process. Founders are individuals that form a new popn and the genetic composition of the new popn is thus a subset of the parent popn
Genetic Bottleneck: another genetic drift like process. a rapid decrease in popn size and thus a big decrease in genetic variation
In what book did Darwin publish his works?
On the Origin of Species
What are the 6 Mechanisms for reproductive isolation?
Geographical: ex. Grand Canyon (North and South Kaibab Squirrel) 2.Ecological: organisms live in different environments 3.Temporal: Organisms reproduce at different times 4.Behavioral: different courtships of species 5.Mechanical: structural differences prevent mating 6.Reproductive failure: offspring is sterile. Ex. Horse + Donkey = Mule
What happens with HW when we have three alleles?
Nothing, you just have another letter
What is done when alloenzymes are looked at in molecular analysis?
They use electrophoresis to look at the different types of enzymes coded by different alleles.
Tree of Life (3 main branches and appearance)
Bacteria - 4bya, Archaea - 4bya? Eukaryotes - 2bya (oldest stromatolitic cherts - 2.5 bya)
Hox d11 expression in fish vs limb buds
-mouse limbs and fish fins form from limb buds in embryos-hox d11 controls limb growth direction-Fish fin only express hoxd-11 and shh in rear of limb bud and early-Mouse limb initially similar but there is additional expression in head-tail axis later in development (slight alterations in gene expression causes big difference)-kitchen pantry ingredients, slight diff use of one ingredient, can makes a totally different dish
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