Explain, Identify, Give Examples

Question 1

Net fitness equations for life history strategies

Answer 1

Wnet = Wearly reproduction + Wlate reproduction
Wearly repro = Wlate repro

Question 2

Life history

Answer 2

The timing of biologically significant events in the lifetime of a typical individual in a given species

Net fitness: an allele’s effect on an individual’s fitness is the sum of all its effects, both good and bad

Question 3

Examples of allometry

Answer 3

human head size, intestines, Irish Elk

Question 4

Issues with Morphological Species Concept

Answer 4

Sexual dimorphism
Polytypism
Cryptic species
Misunderstanding anatomy or behavior
Typological thinking ignores importance of variation

Question 5

Isolating Mechanisms

Answer 5

Biological features or influences that prevent genetic transfer between populations (they prevent a successful “genetic conversation” between populations)
Prezygotic
Postzygotic

Question 6

Prezygotic isolating mechanisms

Answer 6

Prevents transfer of gametes between individuals of 2 populations (i.e., no zygote is formed)
-Temporal isolation
-Habitat isolation
-Ethological isolation
-Mechanical isolation

Question 7

Temporal Isolation

Answer 7

Different activity cycles, not active at the same time of day or year
E.g., cicadas one group emerges from nymphal stage in May/June and dies before August group comes out

Question 8

Habitat Isolation

Answer 8

do not encounter each other because live in different habitats
E.g., spade-foot toads live in different soil types

Question 9

Ethological Isolation

Answer 9

Behavioral differences between individuals that prevent the from considering the other an appropriate mate
E.g., white-footed mouse and cotton mouse do not breed despite overlapping habitat; behavioral imprinting at work
E.g., different species of fireflies have different flash patterns

Question 10

Mechanical Isolation

Answer 10

Incompatibility between genital systems of potential mates
E.g., Great Dane and Chihuahua

Question 11

Postmating Isolating Mechanisms

Answer 11

Gamete incompatibility
Zygote mortality
Hybrid inviability
Hybrid sterility

Question 12

Gamete incompatibility

Answer 12

E.g., marine invertebrates—lots of gametes dispersed into water

Question 13

Zygote mortality

Answer 13

E.g., Leopard frogs and wood frogs

Question 14

Hybrid inviability

Answer 14

E.g., cichlids mated in captivity, swallowtail butterflies

Question 15

Hybrid sterility

Answer 15

E.g., lions and tigers, horse and donkey

Question 16

Assumptions of Cladistics

Answer 16

1. Members of a group of organisms are related to one another by common ancestry
2. For mathematical simplicity, species diverge in a bifurcating fashion. This has resulted in patterns of diversity seen today.
   3.There are features of all organisms called characters (structural, behavioral, biochemical, genetic features) that change over time. We deduce evolutionary relationships by understanding the patterns of changes in the characters over time.

Question 17

Steps to create a cladogram

Answer 17

1.Choose the taxa (the groups) you want to compare. Include an “outgroup” to ‘root’ the tree.
2.Determine the characters to be used
3.Determine the “polarity” of the changes in the characters. This means you need to determine the likely ancestral and derived states of the characters involved.***
4.Use one of the mathematical techniques on a computer to generate ALL possible cladograms
5.Use the “Principle of Parsimony” to help decide which cladogram is the ‘best’ one