A Phylogeny of Beastes
In this exercise, you will reconstruct the evoluonary history of a group of imaginary organisms known as Beases. The Beases are a morphologically diverse group, group, and your analysis will take take advantage of this diversity. diversity. You will infer the most parsimonious (i.e., simplest phylogenec tree for the group of Beases depicted !elow. !elow. The outgroup taxon taxon is indicated, as are six other Bease taxa ("#$. $ollow the instrucons and refer to the class discussions regarding the use of parsimony parsimony in reconstrucng phylogenec trees.
You need to turn in the following% " list of characters used in reconstrucng the phylogeny and the proposed character coding (ta!le & " complete taxon !y character matrix (ta!le ' " tree depicng the most parsimonious esmate of evoluonary relaonships relaonships for the Beases with the characters mapped onto the phylogeny The aached worksheet worksheet on phylogenec phylogenec !asics
)age 1 of 4
1. *onduct a character analysis !y examining the specimens a!ove. +ow many characters can you idenfy -ake a list of these characters, along with short descripons of their various states. se &/s and 0/s to indicate for the presence or a!sence of these characters, respecvely. Remember o code any characer sae in your ougroup as 0. 1nce you have these characters, 2ll in Ta!le &. 2. 1n a scratch piece of paper, 2ll out a taxon !y character matrix similar to the one on Ta!le '. By convenon characters are listed in columns and taxa in rows. 3. In preparaon for determining the most parsimonious tree, organi3e your matrix in descending order, starng with those ingroup taxa that are most similar (i.e., share the most character states with the outgroup. ner his organi!ed daa ino "able 2 # be sure you $ll in he entre able% 4. se your notes from class as an example on how to reconstruct the phylogeny. The 2rst step is to idenfy a homologous trait that disnguishes mem!ers of the g roup of interest from the outgroup (i.e., a synapomorphy. &. 1nce you have determined the phylogeny, make a sketch into the space provided. -ake sure you map the characters onto the tree. '. $inally, answer the 4uesons regarding the !ease phylogeny.
Ta!le &. *haracters used in the Bease phylogenec reconstrucon
(haracer )ame e.g., Ears
(oding scheme 0: absent
1: present
5ye 6i3e
0% small
&% !ig
Teeth
0% 7at
&% sharp
"ntenna
0% simple
&% !ranched
$in
0% a!sent
&% present
$eet
0% round
&% pointed
Tail
0% looped
&% !rushy
6pots
0% a!sent
&% present
Beard
0% a!sent
&% present
Tongue
0% a!sent
&% present
)age 2 of 4
Ta!le '. Taxon !y character matrix (haracers 5ye 6i3e
Teeth
"ntenna
$in
$eet
Tail
6pots
Beard
Tongue
0
0
0
0
0
0
0
0
0
&
0
0
0
0
0
0
0
&
,
&
&
0
0
0
0
&
0
0
B
&
&
0
0
0
0
&
&
0
-
&
&
&
&
0
0
0
0
0
A
&
&
&
&
0
&
0
0
0
(
&
&
&
&
&
&
0
0
0
"a*on +ugroup
$igure &. Bease phylogeny (sketch your phylogenec tree here.
outgroup
,
B
-
A
Beard
(
)ointed $eet
Brushy Tail 6pots Branched "ntenna Tongue $in
6harp Teeth Big eyes
)age 3 of 4
"nswer the following 4uesons using your Bease phylogeny%
&. $or any monophylec clade in your phylogeny, indicate the mem!ers of the clade and list a synapomorphy that de2nes this relaonship /,/B/-/A/( large eyes
,/B/-/A/( sharp eeh
-/A/( -in branched anenna
,/B spos
A/( brushy ail
'. 8ist two autapomorphic traits and state to which taxon each of these !elongs "a*on B beard
"a*on ( poined fee
"a*on ongue
9. Based on your tree, circle all the groups in the list that are sister to each other%
( o ,
A o (
o B
-/A/( o ,/B
o -/(/ A
o ,/ B/ A/ (/ -
( o A/-
)age 4 of 4
