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