Phylogenic reconstruction

Question 1

What is phylogenic reconstruction?

Answer 1

Phylogenetic reconstruction is the understand of relation between species.

Question 2

What is homoplasy?

Answer 2

A character that has evolved at least twice from independent common ancestors.

1. convergent evolution
2. reverse mutation

Question 3

What is monophyly? Paraphyly? Polyphyly? What do they tell us about phylogenies?

Answer 3

Monophyly: group that include all members that share a most common ancestor
Paraphyly: not all descendants are represented within the group
Polyphyly: two or more taxa that does not share a common ancestor

Question 4

What is maximum parsimony?

Answer 4

The hypothesis with the fewest assumptions and entities is the most plausible one. The most parmimonious phylogenetic tree is the one with the least number of changes/mutation, since it is the most likely to occur.

Question 5

What is UPGMA?

Answer 5

UPGMA (Unweighted Pair Group Method using Arithmetic means) is a program used to calculate genetic distance between two species:

1. variable characteristics are converted into a matrix of genetic distances
2. the two most related taxa are identified
3. the distance matrix is recalculated with the two most related taxa merged
4. repeated

Question 6

What is meant for molecular clock? How can it be used?

Answer 6

The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. DNA, RNA or proteins are used.