Problem: Sponge Phylogeny Exercise
While exploring a new planet you come across 6 species which look WEIRDLY like sponges from Earth. Despite this similarity the species look surprisingly different from one another and you select a number of traits that YOU think are important to attempt to group the animals (naming them by what they resemble from Earth) the table below:
|
1= They have it
0= They don't have it
|
Collar/flagella feeding cell
|
Silica
|
Spongin
|
Calcerous spicules
|
6 - ray spicule
|
Skeletal Compounds
|
Pores and canals
|
Multicellular
|
|
Proterospongia
|
1
|
0
|
0
|
0
|
0
|
0
|
0
|
1
|
|
Demospongidae
|
1
|
1
|
1
|
0
|
0
|
1
|
1
|
1
|
|
Calcera
|
1
|
0
|
0
|
1
|
0
|
1
|
1
|
1
|
|
Hexactinellida
|
1
|
1
|
0
|
0
|
1
|
1
|
1
|
1
|
|
Homoscleromorpha
|
1
|
0
|
0
|
0
|
0
|
0
|
1
|
1
|
|
Choanoflagellates
|
1
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
In the space below - Draw the tree that you believe to be the MOST PARSIMONIOUS (requires the fewest steps
Task
• Which species appears to be the outgroup?
• If Spongin was found in the Proterospongia would that make the tree easier to make or harder to make? Why?
• Based on all of the information on the page - are you using evolutionary systematics or phylogenetics? Why?