Chapter 23

Question 1

Systematics

Answer 1

All organisms share many characteristics:​

Composed of one or more cells.​

Carry out metabolism.​

Transfer energy with A T P.​

Encode hereditary information in D N A.

Question 2

Systematics

Answer 2

Study of evolutionary relationships.

Question 3

Phylogeny

Answer 3

Hypothesis about patterns of relationship among species

Question 4

Branching diagrams

Answer 4

Darwin envisioned that all species were descended from a single common ancestor

Question 5

Ancestral characteristic

Answer 5

Similarity that is inherited from the most recent common ancestor of an entire group.

Question 6

Derived characteristic

Answer 6

Similarity that arose more recently and is shared only by a subset of the species.

Question 7

Cladistic method

Answer 7

Characters can be any aspect of the phenotype​

Morphology​

Physiology​

Behavior​

D N A

Question 8

Cladistic analysis

Answer 8

First step is to polarize the characters (are they ancestral or derived?)

Question 9

Cladogram

Answer 9

Depicts a hypothesis of evolutionary relationships.

Question 10

Clade

Answer 10

Species that share a common ancestor as indicated by the possession of shared derived characters.​

A clade is an evolutionary units and refers to a common ancestor and all descendants.​

Synapomorphy – derived character shared by clade members.

Question 11

Plesiomorphies

Answer 11

ancestral states

Question 12

Symplesiomorphies

Answer 12

shared ancestral states

Question 13

Symplesiomorphies

Answer 13

reflect character states inherited from a distant ancestor

Question 14

Homoplasy

Answer 14

a shared character state that has not been inherited from a common ancestor​

Convergent evolution​

Evolutionary reversal

Question 15

Statistical approach

Answer 15

Start with an assumption about the rate at which characters evolve.

Question 16

Molecular clock

Answer 16

Rate of evolution of a molecule is constant through time.

Question 17

Classification

Answer 17

How we place species and higher groups into the taxonomic hierarchy.

Question 18

Classification

Answer 18

Domain​

Kingdom​

Phylum​

Class​

Order​

Family​

Genus​

Species

Question 19

Monophyletic group

Answer 19

Includes the most recent common ancestor of the group and all of its descendants (clade).

Question 20

Paraphyletic group

Answer 20

Includes the most recent common ancestor of the group, but not all its descendants.

Question 21

Polyphyletic group

Answer 21

Does not include the most recent common ancestor of all members of the group.

Question 22

Biological species concept (B S C)

Answer 22

Defines species as groups of interbreeding populations that are reproductively isolated.

Question 23

Phylogenetic species concept (P S C)

Answer 23

Species is a population or set of populations characterized by one or more shared derived characters.

Question 24

P S C solves 2 B S C problems

Answer 24

B S C cannot be applied to allopatric populations – would they interbreed?​

P S C looks to the past to see if they have been separated long enough to develop their own derived characters.​

B S C can be applied only to sexual species.​

P S C can be applied to both sexual and asexual species.

Question 25

Phylogenetics

Answer 25

Basis for all comparative biology

Question 25

Homoplastic convergence

Answer 25

Similar traits have evolved independently in different clades

Question 26

Homologous structures

Answer 26

Derived from the same ancestral source.

Question 27

Comparative Biology

Answer 27

Most complex characters do not evolve in one step​

Evolve through a sequence of evolutionary changes

Question 28

Competing hypotheses

Answer 28

Phylogenetic methods can be used to distinguish between competing hypotheses

Question 29

Phylogenetics

Answer 29

relating to the evolutionary development and diversification of a species or group of organisms, or of a particular feature of an organism.