Phylogenetics Flashcards
What is parsimony?
it assumes that the simplest explanation is true
What is cladistics?
method of building phylogenetic trees which ignores morphological divergence which produces phylogenetic hypotheses and classifications
What does bifurcating mean?
splits in 2 or when branches split in 2
What is a clade?
all descendants of a common ancestor
What are the 4 types of characters?
- Homologous characters
- Analogous characters
- Ancestral characters
- Derived characters
What are homologous characters?
- they reflect underlying genetic similarities
- they indicate common ancestors/genetic relationships
What are analogous characters?
characters in different animals that serve the same function
What are ancestral characters?
old forms of new traits
What are derived characters?
new forms of traits
What are the 3 principles of monophyly?
- Monophyletic taxa
- Polyphyletic taxa
- Paraphyletic taxa
What are monophyletic taxa?
derived from a single ancestral species
What are polyphyletic taxa?
includes species from separate evolutionary lineages
What are paraphyletic taxa?
includes an ancestor and some of its descendants but not all
What are traditional evolutionary systematics?
places together groups of species sharing ancestral and derived characters
What is convergent evolution?
similarity is not due to common ancestry, homologous traits will support the correct phylogeny
What are molecular phylogenetics?
uses molecular differences to build evolutionary trees, DNA sequences and amino acid sequences are most commonly used, it marks how much evolutionary change has occurred
What are the 2 types of classification?
- Monophyletic groups
2. Non-monophyletic groups
What are monophyletic groups?
includes all taxa that descend from a common ancestor
What are non-monophyletic groups?
some but not all of the descendants are from a common ancestor
What are the 2 types of evolutionary traits?
- homologous traits
2. convergent evolution
What are homologous traits/
shared by taxa due to inheritance by a common ancestor
What is convergent evolution?
independant evolutionary events resulting in similar solutions to similar environments
