Summary BSCI207 Evolutionary Trees

Evolutionary Trees



Gae#2914124
What are they ?

-
visualization of speciation linking all species that ever lived on earth


-
aka phylogenic trees

-
show link all the way to a common ancestor


-
can represent species , populations, individs , genes

-
trees are hypothesis and can changed based on new DMA/ fossil evidence


How to read

-
tips = taxa =
youngest lineage




-

branching points = nades =
splitting via speciation



m -
bottom-common ancestor = oldest lineage

-
taxa that share a more common ancestor are more closely related

-
clade =
group of organisms that include single ancestor + all its decendants

-
imagine making one cut on the tree


-
non-clade groups =
poly/paraphyletic
-
imagine making two cuts

-
trees can show same things differently

-
pruning =
simplifying/removing extinct


Anatomy of the Tree

1) outgroup =
lineage outside the clade

A 7

but still related Cless related than
de
· ingroup
-
identify by terminal taxa closest


t the base


2) rost = last common ancestor of ALL


M 3) in group = clade of focus


S
4) nade = speciation (splitting) event


· 5
5) character state change = when a

·3 s new trait evolves
·
6) polytomy = noue w/ 2+ lineages

7) sister youps =
2 clades that are closest relatives to eso Calways the same age

Character = morphological/molecular
8) trait that's distinct/recognizable
9) terminal taxon = doesn't form a clade wanother , extinct or extant