Pre Final Exam Flashcards
What was responsible for the ability of e coli to metabolize citrate?
Change in gene regulation and gene duplication(allowed for aerobic metabolism)
In general, complex traits are controlled by genes and regulatory seq.
What is the origin of snake venom?
Duplication, and change in regulation(expressed in mouth instead of just pancreas)
In general, complex traits are controlled by genes and regulatory seq.
What does the phrase “ontogeny recapitulates phylogeny” mean?
Phylogenesis: Evolutionary diversification
Ontogenesis: Development from early life to maturity
This phrase means developmental steps reflect evolutionary history
Outline Muller’s Ratchet
Asexually reproducing species cannot remove deleterious mutations
Hence one of the many reasons why sex is beneficial, are there others?
What are prezygotic rims?
Prezyogtic reproduction isolation mechanisms
e.g courtship displays, genticalic morphology, sperm egg recognition
Post zyogtic rims:
inviability of embryos (zyogte is earliest state, just egg and sperm)
What are the weaknesses of BSC concept
Not applicable to asexual, or hermaphrodites, or to fossils
Bsc is difficult if species ranges don’t overlap, but they don’t inter.
How is a species defined in PSC?
Smallest cluster with shared features, each lineage should have unique synapomorphy -> PSC
Weaknesses: Can lead to false speciation events
Could be chemical, genetic, etc
Outline semelparity:
Maximum reproductive effort,
occurs when future repro success is uncertain
High trade off between reproduction and survival
What about iteroparity?
The pied flycatcher serves as an example of what?
Divergence in mating preferences in geographic overlap which is evidence of reinforcement,
ie the hybrid is less fit, this results in selection against hybridization
What is anagenesis vs cladogenesis?
ana meaning backwards, so backwards forming
anagenesis: evolution in species w/o speciation
cladogenesis: speciation with rapid change, followed by extinction of old forms
These are interpretations for fossil gap, newer layer only new species
What does recriprocally monophyletic mean?
Presence of a unique synapomorphy, defines PSC
Why is human head lice and public lice not considered parapatric speciation?
Recall:
They diverged 12mya (rather than range expansion after loss of body hair), public lice are actually from gorilla head lice
Define micro vs macro evolution, give the examples
Micro: Occurs at or below species level
- include drift, nat sel
Macro: Occurs above species level
- larger time scales from hundreds of thousands up
- includes adaptive radiatio, origin/diversification of taxa, origin of novel characteristics
Define vicariance
Formation of new geograpgic barrier, results in separation of once continuously distributed species
Define:
Rate of appearance of new genera inversely proportional to number currently existing
Hierarchical model
What is the currently accepted model of speciation?
Punctuated equilibrium,
involves cladogenesis, rapid change then stasis
When more than two species adapt to changes in each other, this is known as?
Diffuse coadapation
When the host doesn‘t diverge but the symbiont does, what does this represent?
Duplication event
When might a symbiont host switch?
If there is strong selection for host to diversify
e.g (if the host is undergoing evolutionary change, that could result in an nonideal environment for the symbiont)
What is Wallaces’ line?
Deep underwater channel that acted as barrier to dispersal of terrestrial animals
True or False:
Mass extinctions can be local
False, by premise they are global
When did amnioids appear?
After the permian, there was less water, more volcanic rock so development of amniot sac was useful
Increased to well over 200 genera
Outline the virus that afflicted rabbits in Australia
Myxomatosis: horizontally transferred
Rabbits evolved immunity, virus evolved less virulence
The guppies were transferred from where to where, and what did this experiment demonstrate?
Guppies were transferred from high predation to a low predation environment,
experiment showed
Define ecological speciation
In ecological speciation, selection for different ecological traits creates reproductive barriers. I
When there is higher adult survival, then is there higher reproductive investment in that moment?
No, there will actually be lower
Characterize semelparity
Low survivorship in offspring
Higher risk with waiting to reproduce
Maximize offspring produced/ lost (same as iteroparity obvs)
100 % Reproductive effort
Why are hawthorn and apple laying Rhagolettis different species?
Because apple layers have been selected for slower maturation to time pupation right, hawthorn layers develop faster, so if a hawthorn layer layed on apple, it pupates to early, and vice versa, if an apple layer lays on hawthorn, it takes to long, and doesn’t prepare for diapause
Why is determining diversity in the fossil record difficult?
The fossil record only includes a small portion of the assumed diversity
Marsupials are an example of solely dispersal?
No, dispersal and vicariance
Define symplesiomorphy, vs synapomorphy, vs autopamorphy
Symplesiomorphy: Ancestral trait shared among at least 2 taxa, not shared by most recent common ancestor of the taxa
Synapomorphy: Shared derived trait of taxa, shared by last common ancestor
Autapomorphy: UNIQUE TRAIT to clade (only found in that clade
What is an evolutionary stable strategy?
A strategy where if the entire population is practicing it, no mutant can invade
ESS is essentially dependent on relative cost and benfit, and frequency of player role
Gondwana was a continent consisting of?
SA, Africa, Aus/NZ, Antarctica, and India
Which extinction event was likley caused by volcanic activity?
Permian anout 200mya
Led to acid rain, less water
Outline the results of the red flour beetle experiment, and its importance for group selection
The experiment demonstrated that group selection is possible in a lab setting
Outline Wynne Edwards vs Williams theory
WE: Group selection for altruism
Williams: In altruistic groups, a mutant would have high fitness, and so selection for mutation individuals, ie altruism bad
How to remember: WE “like WE ARE IN THIS TOGETHER”
When will an altruistic trait spread?
When benefit to recipient multipled by relatedness is greater than cost to donor
Why does eusociality appear frequently in insects?
Due to the haplodiploid system, it is especially the case if a single female is singly mated, that siblings would be more related to one another than to their offspring
Vampire bats was an example of recriprocal altruism, what does this mean.
Regardless of relatedness, bats with prior relations donated food to others
In Side blotched lizards, what did the color morphs correlate with?
Mating behavior,
Orange: Aggressive mate thiefs
Yellow: sneak mates, not agressive
Blue: Smaller, not agressive, many females
The important thing is to understand: frequency dependent selection
Where does most gene regulation occur?
At gene transcription (recall transcription before translation) @ the promoter, another form is alternative splicing
True or False: Most mutations are inherited
False!
Most mutations occur in somatic cells (see notes)
True Or FAlse:
Some mutations are more likely in organism
True!
All mutations are equally likely, and completely random
What is the term for when the entire genome is duplicated?
Polyploidy
Autopolyploid: Duplication within species, allo: due to hybridization
What is the term for when an organism has an uneven(unbalanced) number of chromosomes?
Aneuploidy
True or False:
Most eukaryotes carry more than 2 alleles of a genotype
False: most eukaryotes are diploids, and although traits may be controlled by many alleles (example epistasis, additive effects), each individual only carries 2 (and more can exist in a pop)
When more than one discrete phenotype can arise from a single genotype>?
This is an example of polyphenism
Poly means many, rather than a continous distribution
Give an example of epistatic genes
Example:
Red hair in humans occurs when one gene overrides another to allow expression
What is a QTL?
A quantitative trait locus, which is a genetic locus (region) associated with a quantitative trait
How do you determine if a trait is genetic or environmental?
possible example: Common garden experiment (ie take the specimen to a new environment and see what happens)
Define paraphyla vs polyphyla
Paraphylogeny: Group missing some descendants
Polyphyla: Group does not share most recent common ancestor
Monophyla: Clade, shares ALL descendants of common ancestor
Which basepairs are purines, and pyramidines, and what are transitions vs transversions?
Purines: AG
Pyramidines: CTU
Transition: Purine with purine, or pyramidine with pyramidine
Transversion: Purine with pyramidine or vice versa
An indel is an insertion or deletion of one basepair?
True, but can actually be insertion of more than one bp at a time
Why might extra pair copulation be selected for?
To increase genetic diversity
What causes an OSR?
An operational sex ratio may be caused by male investment into parental care, could result in sex role reversal: females are flamboyant/agressive, males are choosy,could also include gestation
e.g Rhamphomya beetles females cheat at fatness
Outline semelparity vs iteroparity
Semelparity:
100% RE in moment
Low offspring survivorship
Uncertain future success
High trade off between survival and reproduction
Iteroparity:
Less than 100% RE in moment
High survivorship in offspring
Low survival chance at yonu age and higher survival at adulthood
True or False:
Aphids and aphic lice were used as example of weak coadaptation
False, they show strong codiversifcation
(stronger when interaction is obligatory (dont have other host))
Define kin selection, and Hamilton’s rule
A trait is selected for due to the benefits it gives to relatives who also carry this allele
When did amnoid diversity explode?
After Permian extinction, approx 200 mya, from essential zero genera, to over 200
Characterize life before the Cambrian explosion, approx 500mya
Life before: Edicaran
-radial symmetry, simple morphlogy
Cambrian:
Bilateral, locomotion, armour, motility, etc
True or False:
Mammals are diapsids
False: Mammals are synapsids
e.g reptiles are diapsids
What are isoforms?
Similar proteins, resulting from alternative splicing of preMRna
What are the pros and cons of molecular phylogenies?
Pros:
Unambigious character states
Millions of character States available
Cons:
Hard to distinguish homoplasy vs homology
Restricted to extant taxa (DNA only lasts about 100k years)
What is the importance of neutral theory?
Neutral theory acts as a null-hypothesis for natural selection
What is neutral theory?
The theory that most mutation in genome is due to drift rather than natural selection.
Predicts: Rate of mutations accumulating is relatively constant
Mutations should accrue more rapdily in areas of genome that don’t influence phenotype (silen tmutations accumulate more rapidly than non silent mutations
