Complete the following exercise in building a phylogenetic tree using the cladis
ID: 164228 • Letter: C
Question
Complete the following exercise in building a phylogenetic tree using the cladistics method at home. You have the following information about four plant species. Plant X is the outgroup. Recode the characters as ancestral or derived and then build a phylogeny. There may be more than one possible tree.
Recoded characters
n = number of
charaacter states
plant reproductive body Types of leaves Type of stem Rhizomes Plant height A seeds compound smooth absent short B seeds compound smooth present tall C seeds compound hairy present tall D seeds simple hairy present short X spores simple hairy present shortExplanation / Answer
In the given example, presence of seeds, compound leaves, smooth stem, absence of rhizome and tall plant height are apomorphic characters or derived characters.
Presence of spores, simple leaves, hairy stem, presence of rhizome, and short plan height are plesiomorphic characters.
Cladistics is a method to hypothesize the relationships among organisms and to reconstruct evolutionary trees on the basis of such information. The basis of cladistics is data on the characters or traits of the organisms in which we are interested.
Plant
1 Reproductive body
2 Types of leaves
3 Typeof stem
4 Rhizomes
5Plant height
A
Apomorphic (derived)
Apomorphic
Apomorphic
Apomorphic
Plesiomorphic
B
Apomorphic
Apomorphic
Apomorphic
Plesiomorphic
Apomorphic
C
Apomorphic
Apomorphic
Plesiomorphic
Plesiomorphic
Apomorphic
D
Apomorphic
Plesiomorphic
Plesiomorphic
Plesiomorphic
Plesiomorphic
X
Spores
Simple
Hairy
Present
Short
n = number of
charaacter states
5
5
5
5
5
n-1
4
4
4
4
4
Plant
1 Reproductive body
2 Types of leaves
3 Typeof stem
4 Rhizomes
5Plant height
A
Apomorphic (derived)
Apomorphic
Apomorphic
Apomorphic
Plesiomorphic
B
Apomorphic
Apomorphic
Apomorphic
Plesiomorphic
Apomorphic
C
Apomorphic
Apomorphic
Plesiomorphic
Plesiomorphic
Apomorphic
D
Apomorphic
Plesiomorphic
Plesiomorphic
Plesiomorphic
Plesiomorphic
X
Spores
Simple
Hairy
Present
Short
n = number of
charaacter states
5
5
5
5
5
n-1
4
4
4
4
4