BIOL 211 Concepts of Zoology
Exam 2 Study Guide
Chapter 10
10.1 What is meant by binomial nomenclature? Describe the convention for writing
binomials.
● Each species has a unique name
● Species name is Genus + species
○ Genus → capitalized, species → not
● Entire name is italicized
○ Ex. Homo sapiens, Daphnia magna
10.2 Taxonomy vs. systematics?
● Taxonomy → important for naming species
● Systematics → important for grouping animals based on common descent
(sharing a common ancestor)
10.3 What are the three fundamental ideas used in species concepts?
1. Descent → derived from common ancestral population
2. Smallest grouping → cohesive, share morphology + genetics
3. Reproductive
a. Sexual populations interbreed
b. Asexual populations respond as a unit to evolutionary forces
1. Biological species concept → defines a mechanism (process) for speciation
a. Species = interbreeding population reproductively isolated from others
i. “Who can mate with who?”
b. Useful and widely accepted
c. Problems:
i. Time not considered
ii. Asexually reproducing organisms are difficult to apply
iii. Hybrids occur
1. Ex. mule
2. Morphological (typological) species concept → defines phenotypic group +
relies on morphological similarity
a. Holotype specimen → the idealized form against which all other
specimens are compared
b. Problems:
i. Geographic variation → same animal can look different
, ii. Sexual dimorphism → females and males look different
3. Phylogenetic species concept → species is smallest possible grouping of
distinct organisms
a. Defines pattern (not process) of speciation (evolution)
b. Emphasis on independently evolved groups of organisms
i. Recognizes species as a lineage
ii. Includes asexual populations
1. New techniques (ex. DNA barcoding) and data lead to
constant reevaluation of species concepts
10.6 Define the following terms:
● Clade (monophyletic group) → a lineage that includes the ancestor and all
descendants
a. “Gold standard” for phylogenetic reconstruction
b. Defined by one or more synapomorphies
c. Not a taxonomic group
● Synapomorphy → a unique feature shared by all members of a clade and not
found in any other organisms outside that clade
a. Ex. hair (only mammals have hair)
● Paraphyletic group → a group of animals that contain a common ancestor, but
does not include all descendants
● Cladogram → branching diagram that shows nested hierarchy (relationships) of
clades (monophyletic groups) defined by synapomorphies
a. Nested hierarchy
b. ‘Angle’ diagram
● Sister group → two descendants that split from a common ancestral node
● Parsimony → ‘the simplest explanation that can explain the data’ is to be
preferred
a. State in which a phylogenetic tree features the fewest possible number of
common ancestors / minimizing the total number of evolutionary steps
10.7 What are some sources of phylogenetic information?
● Characters → sources of information
○ Anything that can be described or measured
Exam 2 Study Guide
Chapter 10
10.1 What is meant by binomial nomenclature? Describe the convention for writing
binomials.
● Each species has a unique name
● Species name is Genus + species
○ Genus → capitalized, species → not
● Entire name is italicized
○ Ex. Homo sapiens, Daphnia magna
10.2 Taxonomy vs. systematics?
● Taxonomy → important for naming species
● Systematics → important for grouping animals based on common descent
(sharing a common ancestor)
10.3 What are the three fundamental ideas used in species concepts?
1. Descent → derived from common ancestral population
2. Smallest grouping → cohesive, share morphology + genetics
3. Reproductive
a. Sexual populations interbreed
b. Asexual populations respond as a unit to evolutionary forces
1. Biological species concept → defines a mechanism (process) for speciation
a. Species = interbreeding population reproductively isolated from others
i. “Who can mate with who?”
b. Useful and widely accepted
c. Problems:
i. Time not considered
ii. Asexually reproducing organisms are difficult to apply
iii. Hybrids occur
1. Ex. mule
2. Morphological (typological) species concept → defines phenotypic group +
relies on morphological similarity
a. Holotype specimen → the idealized form against which all other
specimens are compared
b. Problems:
i. Geographic variation → same animal can look different
, ii. Sexual dimorphism → females and males look different
3. Phylogenetic species concept → species is smallest possible grouping of
distinct organisms
a. Defines pattern (not process) of speciation (evolution)
b. Emphasis on independently evolved groups of organisms
i. Recognizes species as a lineage
ii. Includes asexual populations
1. New techniques (ex. DNA barcoding) and data lead to
constant reevaluation of species concepts
10.6 Define the following terms:
● Clade (monophyletic group) → a lineage that includes the ancestor and all
descendants
a. “Gold standard” for phylogenetic reconstruction
b. Defined by one or more synapomorphies
c. Not a taxonomic group
● Synapomorphy → a unique feature shared by all members of a clade and not
found in any other organisms outside that clade
a. Ex. hair (only mammals have hair)
● Paraphyletic group → a group of animals that contain a common ancestor, but
does not include all descendants
● Cladogram → branching diagram that shows nested hierarchy (relationships) of
clades (monophyletic groups) defined by synapomorphies
a. Nested hierarchy
b. ‘Angle’ diagram
● Sister group → two descendants that split from a common ancestral node
● Parsimony → ‘the simplest explanation that can explain the data’ is to be
preferred
a. State in which a phylogenetic tree features the fewest possible number of
common ancestors / minimizing the total number of evolutionary steps
10.7 What are some sources of phylogenetic information?
● Characters → sources of information
○ Anything that can be described or measured
