Lecture 11- Phylogenies Flashcards
Allele frequencies are equal to
the frequency of a gamete carrying that allele
p^2 + 2pq +q&2=
1, will always add to 1
Equation to determine homozygous dominant offspring
p^2
determining homozygous recessive offspring
q^2
determining the heterozygous offspring
2pq
When is a population not in HW
when the observed frequencies do not equal the expected frequencies under the HW principle
basal taxon
diverged earliest from the group (least related to everything else on the tree)
Sister Taxa
share an intermediate common ancestor not shared by any other organisms on the tree
The more recent the branching is, the more ______ related they are
closely
Taxa
organisms at the end of lines
Branches of phylogenetic trees can be rotated around _______ without changing the meaning of the tree
branch points
When comparing trees to see if they are the same begin by looking at
sister taxa
often branching patterns match
phenotypic similarity patterns
Analogies
similarities between organisms that are due to convergent evolution
Homologies
phenotypic and genetic similarities due to shared ancestry
Proximity at the tips is ____important than the path through the tree that connects them
LESS
What tells you if a species is more closely related than another
closest most recent common ancestor (closer MRCA= closer related)
Convergent evolution
Different lineages produce the same traits due to similar pressures
Cladistics
common ancestry is primary criterion used to classify organisms
Clade
group of species that includes an ancestral species and all its descendants
the same derived trait occurring multiple times (in different locations), is an indicator that ______ _______ occurred
Convergent Evolution
Monophyletic group
a species that includes all ancestors and descendants (same as a clade)
Paraphyletic group
includes a common ancestor and some but NOT ALL descendants
Polyphyletic group
Includes all descendants but not the common ancestor