Molecular ecology.2 Flashcards
How can genetic variation change in a population without natural selection?
population size and structure
What does the outlier represent?
where the fst value is greater than expected by neutral expectations
Name the main categories of omics (5)
- genomics
- proteomics
- metabolomics
- phenomics
- transcriptomics
What is phenomics?
study of phenotypes, morphological, biochemical and physical traits
What are quantitative traits?
phenotypes that vary in degree and can be attributed to polygenic effects
What is the coalescene theory?
A model of the effect of genetic drift viewed as a genelogy that considers all pathways of inheritance
What is the role of recombination of DNA?
it breaks up the physical co inheritance of DNA variation
Where does NO recombination happen?
mitochondrial DNA
Define homologue
a character shared by 2 species because it was inherited from a common ancestor
Define homoplasy
a character shred by 2 species but is not inherited by shared ancestry, by natural selection instead
What is the difference between synapomorphy and apomorphy?
synapomorphy= types of characters shared by common ancestry and between 2 species apomorphy= characters shared by only species within the tree
What are orthologs?
genes shared by a common ancestor
What are paralogs?
copies of genes found within the same genome that don’t share a common ancestor
What is the difference between convergent and parallel evolution?
convergent = where traits are produced by different genes or developmental pathways parallel = traits are produced by same genes or developmental pathways
Name 4 types of how homoplasy can be created
- genes evolve independently of species
- convergent evolution
- parallel evolution
- evolutionary reversals
Name the 3 components of phylogenetic reconstruction
cladistics
phenetics
statistics
What is cladistics?
a method of classification of organisms that aims to identify shared characteristics which have derived from a common ancestor of a group of species during evolution,
What is phenetics?
a method of classification of organisms based on their overall similarity and morphology
How does statistics classify organisms?
single tree explains evolution in terms of probability given the data
What does parsimony mean?
we are minimising the number of evolutionary steps it takes to explain the evolutionary relationship between species
Define pleisomorphy
characters that are ancestral shared by 2 or more taxa
Define autapomorphy
a derived trait that is not shared with any other taxa, unique to teh species but not grouping to any other species
Name the 2 models that can be created for phylogenetic reconstruction by statistics
- juke cantor= assumes any transitions nucleotides in sequences have equal probability
- kimura= transition have a substitution rate which is different from the transversions
Define adaptive radiation
the process by which organisms diversify rapidly from ancestral species into new forms
What is the ectomorph concept by Ernest Williams in 1972?
‘species with teh same structural habitat/niche similar in morphology but not necessarily close phyletically’
Name the 4 factors which make up adaptive radiation
- common ancestry
- strong link between environments and specific traits
- fitness advantage
- rapid rise of new species
Where can adaptive radiation be clearly seen?
the Hawaii islands, emerged as hotspots, crating new habitats out of no where
