Introduction

Question 1

What is functional morphology?

Answer 1

the relationship between the form (structure) and the function of tissues, organs, or organ systems within organisms (in an adaptive and evolutionary context)

Question 2

What are primitive structures?

Answer 2

the original condition of that trait in a common ancestor

Question 3

What are derived structures

Answer 3

indicates a notable change from the original condition (a modification of the primitve trait)

Question 4

What are homologous structures?

Answer 4

A homologous structure is found in 2 or more organisms that is derived from a common ancestry. structure has a similar anatomical position but may not serve the same function or look similarly.
homologous structures can be used to investigate phylogenetic relationships and construct trees.
e.x. middle ear ossicles of more derived vertebrates are homologous with the jaw elements of more primitive vertebrates

Question 5

What are analogous structures?

Answer 5

analogous structures are found in 2 or more organisms that look similar and are used for the same function but have evolved independently of one another. Produced for convergent evolution

Question 6

What is Exaptation (preadaptation)?

Answer 6

a pre-existing structure that is inherited from an ancestor but is used for an unrelated function

Question 7

What is descent with modification?

Answer 7

Evolutionary change that involves continuous modification of ancestral structures?

Question 8

What is Phylogeny?

Answer 8

The study of evolutionary relatedness among past and present taxonomic groups (i.e., relationships among living things through time)
Can be visualized as evolutionary trees

Question 9

What is Cladistics?

Answer 9

a system of biological classification in which organisms are categorized based on shared derived characteristics (synapomorphies) that can be traced to a group’s most recent common ancestor

Question 10

What is Synapomorphy (and apomorphy)?

Answer 10

A shared derived trait found in 2 or more taxa that are used to infer a phylogenetic relationship

Question 11

What is Symplesiomorphy?

Answer 11

a shared primitive trait that is relatively unchanged from the ancestral form (not informative and tells nothing about relatedness)

Question 12

What is autapomorphy?

Answer 12

a derived trait that is unique to only one group (not informative, tells nothing about relatedness)

Question 13

What is Homoplasy?

Answer 13

a shared derived trait found in 2 or more taxa that did not arise from a common ancestor

Question 14

cladogram

Answer 14

a branching diagram showing the evolutionary relationship between taxa

Question 15

clade

Answer 15

a natural evolutionary lineage that includes the most recent common ancestor and all and only its descendants (forms a monophyly)

Question 16

monophyly

Answer 16

a complete clade that consists of the most recent common ancestor and ALL of its descendants

Question 17

Paraphyly

Answer 17

an incomplete clade that includes the most recent common ancestor but NOT all of its descendants

Question 18

Polyphyly

Answer 18

an artificial clade composed of unrelated organisms descended from more than one ancestor (containing misleading convergent or homoplastic traits)

Question 19

sister taxa

Answer 19

groups of organisms that share an immediate common ancestor and hence are each others closest relatives

Question 20

Crown group

Answer 20

includes the most recent common ancestor of all living taxa of a particular group (plus any extinct descendants)

Question 21

stem group

Answer 21

includes extinct taxa related to but not part of the crown group. i.e., extinct lineages that diverged below the most recent common ancestor of the crown group.

Question 22

total group

Answer 22

composed of both the crown and stem groups

Question 23

Isometric growth

Answer 23

all structures of an organism have the same rate of growth so that its shape is consistent throughout ontogeny

Question 24

allometric growth

Answer 24

certain structures of an organism have a differential rate of growth in an individual throughout ontogeny

Question 25

what is the size range of vertebrates?

Answer 25

7.7 mm to 33 m

Question 26

What happens to volume and surface area as an organism increases in size?

Answer 26

volume, which is proportional to mass, and surface area do not increase at the same rate. Volume/ mass increases faster than the surface area with an increase in overall size, thus supportive bones must become more robust

Question 27

heterochrony

Answer 27

evolutionary change in the timing or rate of developmental events in the descendant species when compared to the ancestral condition (i.e., ontogenetic change with phylogenetic consequences leads to changes in size and shape.

Question 28

Paedomorphosis

Answer 28

juvenile characteristics of ancestors appear in the adults of their descendants (includes progenesis and neoteny)

Question 29

progenesis

Answer 29

acceleration of reproductive development relative to somatic development when compared to the ancestral condition (maturation of the reproductive organs is accelerated relative to the non-reproductive body parts)

Question 30

Give an example of progenesis

Answer 30

Bolitoglossa occidentalis sexual maturity (relative to somatic development) occurs earlier than in closely related species. retaining small size and webbed hands and feet which are adaptations for arboreal lifestyle

Question 31

neoteny

Answer 31

slowing down of somatic development relative to reproductive development when compared to the ancestral condition (i.e., delayed development or resorption of non-reproductive body parts relative to the maturation of reproductive organs

Question 32

Give an example of neoteny

Answer 32

axolotls retain external gills, even after becoming reproductively mature

Question 33

Peramorphosis

Answer 33

adult somatic characters of descendants are exaggerated in shape (undergoes an extended period(s) of growth) when compared to that of ancestors (includes acceleration and hypermorphosis)

Question 34

acceleration

Answer 34

rate of development of a somatic structure is increased compared to the ancestral condition

Question 35

hypermorphosis

Answer 35

offset in the developing somatic structure is delayed compared to the ancestral condition