Summary Part 2 -- Neutral evolution & genetic distance
24 views 0 purchase
Course
Evolutionary Development Biology
Institution
Vrije Universiteit Amsterdam (VU)
This is a summary of part 2 Neutral evolution & genetic distance of Evolutionary Development. With all of my summaries for this course I passed it with an 7,7 !
Neutral evolution & Genetic distance
Neutral evolution
Undirected changes in allele frequencies; arise from the fact that
offspring is a sample of parental genomes
Neurtral evolution depends on population size (important in small
populations) and breeding structure (harems
Examples:
Genetic drift
Colonisations (founder effects)
Bottleneck effects: drastische afname in populatiegrootte door
omgevingsfactoren (uitbraak dodelijke ziekte)
o Demographic event after origin of H. sapiens – bottleneck effect ±
70000 y BP
Small populations can evolve quickly in large populations selection is necessary
Diffusion model of Kimura
Fixation: loss of polymorphism, a locus becomes monomorphic by random genetic
drift
Fixation is strongly dependent on effective population size (Ne) (this can be much
smaller than real population size)
Ne = 4NfNm/Nf + Nm
The fate of new alleles depends strongly on Ne. In many cases the Ne is too small to
prevent that mutation and drift determine the course of evolution
2N alleles in population of diploid organisms
All alleles have same probability to fix – likelihood of fixation is K = 1/(2N)
If allele emerge by mutation at frequency µ the probability of a new allele emerging is
2Nµ per generation time
Fixation is now K= 1/(2N) * 2Nµ = µ
Under equilibrium conditions fixation frequency is numerically equal to mutation
frequency
Harems
Ne << N
Polygynous social structure is accompanied by sexual dimorphism
Polydactyly (hebben van meer vingers/tenen) among Amish
Congenital dominant defect
The initial colonizers of Amish carried this allele already
Population which is established by single colonization often shows deviating genetic
composition
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller biomedicalsciencesvu. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.34. You're not tied to anything after your purchase.
