Bieb 140 Lecture 2

Front 1

phylogenetic tree

Back 1

shows relationships

Front 2

genealogy

Back 2

whos related to whom and where did it come from

Front 3

phenetic vs phylogenetic tree

Back 3

phenetic= superficial similarities

phylogenetic = reflect evolutionary relationships

depict where things came from not how they look like today

Front 4

monophyletic group

Back 4

same ancestor and all its decendents

defined by inclusion

Front 5

paraphyletic group

Back 5

common ancestor but not all descendents

defined by exclusion.

Made to map out ways of making a living rather than ancestry,

Not very good

Front 6

polyphyletic group

Back 6

no most common recent ancestor

but different groups s

Front 7

sister groups

Back 7

species or taxa that are eachothers closet relatives.

are always monophyletic

Front 8

how do we build phylogenetic trees

Back 8

we build trees using characters,

Front 9

characters

Back 9

each character provides a hypothesis of relationship, molecular, morphological

Front 10

plesiomorphic

Back 10

primitive

type of character tree

Front 11

apomorphic

Back 11

derived

type of character for tree

Front 12

autoapomorphy

Back 12

really defines species. this is a type of character only seen in this clade/ taxa.

sets it apart

Front 13

rooted versus unrooted: tree

Back 13

rooted= follows temporal path

unrooted= does not follow temporal path

Front 14

Parsimony: tree

Back 14

based on Occam's Razor, always pick the shortest tree

minimum number of evolutionary changes

cons: this may be wrong hypothesis not based on biology

Front 15

neighbor joining: tree

Back 15

takes a sequence matrix, uses distances among genes or taxa to build tree

Front 16

maximum likelihood: tree

modern way

Back 16

takes a set of molecular data, only,

hypothesis : give computer model of how likely sequences of genes are going to change .

use model of change, make multiple topologies

Makes multiple trees, with a percentage of how likely it fits based on the your model.95 100

Front 17

fossil record: divergence time

Back 17

is a minimum estimate of time because it is incomplete. not everything becomes a fossil.

even fossil may have evolved earlier.

Front 18

molecular time

Back 18

genetic distance between 2 species is a function of time past. will accumulate more mutations as time since divergence happened

Front 19

genetic distance

Back 19

% sequence divergence between taxa, calibrated by fossil records

Front 20

evolutionary rates / clock

Back 20

NOT constant. different genes evolve at different rates.

poor calibration = wrong rates

Front 21

missing branches problem

Back 21

missing taxon from tree. may have not been sampled yet, extinct,

the age of each taxon/ species is anchored to its sister. each node is anchored by two species, may make the node appear older than it is.

gives older ages

Front 22

biforcating versus budding phylogeny

Back 22

biforcating= internal branches