Chapter 2: Systematic procedures

Question 1

The fundamental unit of classification schemes

Answer 1

Species

Question 2

What is a morphospecies?

Answer 2

A species designated and clearly separated from other species based on recognized unequivocal morphological features.

Question 3

The concept that species are groups of actually or potentially interbreeding populations which are reproductively isolated from other such groups

Answer 3

the biological species concept

Question 4

________ deals with the theory and practice of describing biodiversity, arranging this diversity into a system of classification, and devising identification keys. It includes the rules of nomenclature that govern use of taxonomic names.

Answer 4

Taxonomy

Question 5

________ emphasizes the study of relationships postulated to exist among species or higher taxa, such as families or orders.

Answer 5

Systematics

Question 6

What is an apomorphy?

Answer 6

A recently evolved, derived, or advanced character.

Question 7

What is a pleisomorphy?

Answer 7

A more ancestral, primitive, or generalized character.

Question 8

What is a synapomorphy?

Answer 8

A shared derived character.

Question 9

What are monophyletic groups (or clades)?

Answer 9

Groups containing an ancestor and all it descendant taxa.

Question 10

What is a symplesiomorphy?

Answer 10

A shared primitive character.

Question 11

What is an autapomorphy?

Answer 11

A specialized character that is present in only a single taxon.

Question 12

What are sister groups?

Answer 12

The most closely related clades in the nodes of a cladogram.

Question 13

What are homoplasies?

Answer 13

Shared, independently derived similarities.

Question 14

What are polyphyletic groups?

Answer 14

Groups containing the descendants of different ancestors.

Question 15

What are paraphyletic groups?

Answer 15

Groups that do not contain all the descendants of a single ancestor.

Question 16

What are grades?

Answer 16

Groups that are defined by their morphological or ecological distinctness and not necessarily by synapomorphies.

Question 17

What are meristic characters?

Answer 17

Almost any countable structure, including numbers of scales, gill rakers, cephalic pores, and so on. They are clearly definable, and usually other investigators will produce the same counts.

Question 18

What are morphometric characters?

Answer 18

Measurable structures such as fin lengths, head length, eye diameter, or ratios between such measurements. They are sometimes hard to define exactly, and being continuous variables, they can be measured to different levels of precision and so are less easily repeated.

Question 19

What are anatomical characters?

Answer 19

Characters of the skeleton and soft anatomy, such as the position of the viscera, divisions of muscles, and branches of blood vessels.