Phylogenetics

Question 0

What is systematics?

Answer 0

The classification of organisms and the determination of their evolutionary relationships.

Question 1

What is phylogeny?

Answer 1

The evolutionary history of a species or a group of related species.

Question 2

What is taxonomy?

Answer 2

The ordered division and naming of organisms.

Question 3

What are the two key features of binomial nomenclature?

Answer 3

1. The genus
2. Unique for each species within the genus.
   Ex. Homo sapiens

Question 4

List the taxonomic groups fro, broad to narrow.

Answer 4

1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species

Question 5

What does a branch point on a phylogenetic tree represent?

Answer 5

The divergence of two species.

Question 6

What are sister taxa?

Answer 6

Groups that share an immediate common ancestor.

Question 7

What can we or cant’t we learn from a phylogenetic tree?

Answer 7

1. Show patterns of descent, not phenotypic similarity.
2. Do not indicate when species evolved or how much change occurred in a lineage.
3. It should not be assumed that a taxon evolved from the taxon next to it.

Question 8

Why is differentiating between homology and analogy important when constructing a tree?

Answer 8

So you can distinguish whether similarity is due to shared ancestry (homology) or convergent evolution (analogy).

Question 9

What is molecular systematics?

Answer 9

The use of DNA and other molecular data to determine evolutionary relationships.

Question 10

What is cladistics?

Answer 10

Groups organisms by common descent.

Question 11

What is a monophyletic clade?

Answer 11

A grouping that consists of the ancestor species and all its descendants.

Question 12

What is a paraphyletic clade?

Answer 12

Grouping that consists of the ancestral species and some, but not all, of its descendants.

Question 13

What is a polyphyletic clade?

Answer 13

A grouping that consists of various species with different ancestors.

Question 14

What is a clade?

Answer 14

A group of species that includes an ancestral species and all its descendants.

Question 15

What is the difference between a shared ancestral character and a shared derived character?

Answer 15

A shared ancestral character is a character that originated In an ancestor of the taxon. A shared derived character is an evolutionary novelty unique to a particular clade.

Question 16

What is an outgroup? An ingroup?

Answer 16

An outgroup is a group that has diverged before the ingroup. The ingroup is compared to the outgroup to differentiate between shared derived and ancestral characteristics.

Question 17

How are the outgroup and ingroup species used to offer a phylogenetic tree?

Answer 17

The ingroup species are compared to the outgroup to differentiate between shared derived and ancestral characteristics.

Question 18

What can branch length indicate?

Answer 18

It can reflect the number of genetic changes that have taken place in that lineage. It can also represet chronological time.

Question 19

What is the molecular clock?

Answer 19

A method for estimating the time required for a given amount of evolutionary change, based on the observation that some regions of genomes evolve at constant rates.