Systematics

Question 1

Three key features of a phylogenetic tree

Answer 1

Do not show age of species or phenotypic similarity and taxonomy do not evolve from each other

Question 2

What do homology and homoplasy mean?

Answer 2

Homology means having phenotypic and genotype can similarities due to shared ancestry. Homoplasy is having similarities with an organism in another evolutionary lineage, due to exposure to similar environmental conditions.

Question 3

Define plesiomorphy and synapomorphy

Answer 3

Plesiomorphy is having shared ancestral characteristics from a distant common ancestor. Synapomorphy is having shared derived characteristics from a recent common ancestor. Shared ancestral characteristics means a character in an ancestor and many groups, whereas in derived characteristics the character is found in the ancestor and a single group.

Question 4

Define molecular clock

Answer 4

Measures time since divergence from a common ancestor by looking at number of differences in nucleotide or protein sequences.

Question 5

Define phylogeny and taxonomy

Answer 5

Phylogeny is the study of evolutionary relationships and taxonomy is naming, describing and classifying organisms. Systematics is the discipline that focuses on classifying and determining evolutionary relationships between organisms.