Week 9

Question 1

Describe binomial nomenclature

Answer 1

Each species has two names:
1-Indicates the genus at which it belongs
2-Indicates the species

Question 2

Describe Biological Species Concept

Answer 2

“Species are group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups”

Question 3

What are the four problem of the Biological Species Concept?

Answer 3

• It cannot be applied to asexual species
• It cannot be applied to allopatric species
• It cannot be applied to organisms separated by geological time
• It doesn’t consider the level of reproductive isolation

Question 4

Describe evolutionary (or lineage) species concept:

Answer 4

Species are seen as branches of the tree of Life

Question 5

Describe the morphological species concept:

Answer 5

Species consist of individuals with the same morphology

Question 6

Describe Phylogentic Species Concept:

Answer 6

Is based on two assumption:
1-Group taxa using the criterion of monophily (shared common ancestor)
2-Ranks group by the criterion of having the smallest diagnosable monophyletic group possible

Question 7

What’s Phylogeny?

Answer 7

Is the evolutionary history of relations among organisms and their genes

Question 8

What’s a node on the Phylogenetic tree?

Answer 8

A point at which two lineages diverged in the past

Question 9

What’s the root of the Phylogenetic tree?

Answer 9

It rappresent the common ancestor of one or two lineages

Question 10

What’s a clade?

Answer 10

Any taxon that consists of all the evolutionary descendants of a common ancestor

Question 11

What are sister species?

Answer 11

Two species that are each other closest relatives

Question 12

What are sister clades?

Answer 12

Two clades that are each other closest relatives

Question 13

What’s systematics?

Answer 13

Is the study and classification of biodiversity

Question 14

What’s a taxon?

Answer 14

Any group of species that we designate with a name

Question 15

What’s cladistic?

Answer 15

Is the study of clades

Question 16

What’s a lineage?

Answer 16

A series of organisms that is connected by a continuos line of descent from a common ancestor

Question 17

What are homologous features?

Answer 17

Features shared by two or more species that were inherited from a common ancestor

Question 18

What is a Plesiomorphy?

Answer 18

A trait that was also present in the ancestor of a group (It’s also called the ancestral state of a trait)

Question 19

What’s a Synapomorphy?

Answer 19

A trait found in the descendant that differ from its ancestral state (It’s also called derived trait)

Question 20

What’s an homoplasy?

Answer 20

A character shared between a set of species that wasn’t present in their common ancestor

Question 21

What are the two reasons of origin of homoplasies?

Answer 21

1-Convergent Evolution

2-Evolutionary reversal

Question 22

Describe the effect of convergent evolution on a trait:

Answer 22

Independently evolved traits subjected to similar selective pressure may become similar superficially

Question 23

Describe evolutionary reversal:

Answer 23

A character reverts from its derived state back to the ancestral state.

Question 24

What’s the parsimony principle?

Answer 24

The simplest explanation (the one with the fewest number of homoplasies) is the preferred one.

Question 25

What are the five sources of data used to construc phylogenetic trees?

Answer 25

Morphology
Development
Paleontology
Behavior
Molecular Data

Question 26

Describe how morphology is used to build a phylogenetic tree:

Answer 26

We observe the presence, size and shaped of body parts

Question 27

Describe how Development is used to build a phylogenetic tree:

Answer 27

We observe the similarities in the developmental pattern

Question 28

Describe how Paleontology is used to build a phylogenetic tree:

Answer 28

Fossil record provide important references that can help us distinguis between ancestral and derived traits

Question 29

Describe how Behavior is used to build a phylogenetic tree:

Answer 29

Some behavioral traits are culturally transmitted but others are inherited

Question 30

Describe how Molecular Data is used to build a phylogenetic tree:

Answer 30

We use DNA for phylogenetic analyses

Question 31

What are the three main uses of Phylogenetic Trees for biologists?

Answer 31

• They help them recostructing the past
• Compare and contrast living organisms
• Ancestral state of traits can be reconstructed

Question 32

What are the three different type of taxa?

Answer 32

• Monophiletic
• Polyphiletic
• Paraphiletic

Question 33

Describe monophiletic taxa:

Answer 33

Taxa that contain the ancestor and all the descendants

Question 34

Describe polyphiletic taxa:

Answer 34

Taxa that contain only the descendants and exclude the common ancestor

Question 35

Describe paraphiletic taxa:

Answer 35

Taxa that don’t include all the descendants from a common ancestor.