Module 7

Question 1

Classification

Answer 1

The ordering of organisms into categories, such as orders, families, and genera to show evolutionary relationships.

Question 2

Animalia

Answer 2

Any organism that moves about and ingests food.

Question 3

From Animalia to Mammalia

Answer 3

Kingdom Animalia
Subkingdom Metazoa
|
Phylum Chordata
|
Subphylum Vertebrata
|
Class Mammalia

Question 4

homologies

Answer 4

Traits that are shared by species on the basis of descent from a common ancestor.

Question 5

Analogies

Answer 5

Traits that are shared due to independent functional adaptation, not on shared evolutionary descent.

Question 6

Homoplasy

Answer 6

The process that leads to the development of analogies. Can also happen between groups that share some homologies but also share similar environments.

Question 7

Evolutionary systematics

Answer 7

A way of mapping evolutionary relationships based on similarity or difference of traits.

Question 8

Cladistics

Answer 8

A way of mapping evolutionary relationships based on kinds of homologies, in which some traits are given higher priority over others in determining relatedness.

Question 9

Ancestral Characters

Answer 9

Traits that show a very remote ancestry. If these characters are shared by two or more organisms it is because it is inherited from a distant ancestor. (For example: the 5-finger forelimb homology in vertebrates.

Question 10

Derived Characters

Answer 10

Traits that distinguish particular evolutionary lineages. In cladistics, these characters help make accurate interpretations of closer relationships. (example: the forelimb homology doesn’t allow differentiation between reptiles, birds, and mammals, but further modifications to the forelimb, such as a paw or wing or hand does.)

Question 11

Shared Derived Characters

Answer 11

Traits that distinguishes a particular group from any other group. (example: all mammals have fur, give birth to live babies, and feed them milk-no other vertebrates does this).

Question 12

Geographical Isolation

Answer 12

Due to physical barriers, the gene pool of a population is divided, preventing gene flow. Genetic differences accumulate overtime in each of the new populations (caused by mutation, genetic drift, or natural selection as a result of of different environmental selective pressures, all leading to new traits), until the populations are so different that even if the barrier were removed, they would no longer be able to breed and produce viable offspring. Thus new species result.

Question 13

Behavioral Isolation

Answer 13

When new traits that accumulate in segregated or isolated populations are behavioral and result in differences in courtship or mating practices. Although the two populations could still biologically interbreed, the cues for mating are off enough that they aren’t recognizable to each other and thus no reproduction occurs. Gene flow is cut off and the effect is similar to geographical isolation, resulting in new species.

Question 14

Cenozoic Era

Answer 14

65 million years ago - present

Question 15

Mesozoic Era

Answer 15

225 - millions of years ago ( a lot of reptiles and dinosaurs).

Question 16

Paleozoic Era

Answer 16

570 - 225 million years ago.

Question 17

Placental Mammals( Eutheria Mammals).

Answer 17

Mammals that are born inside the mother and develop within a placenta (versus monotremes and marsupials that have an external pouch).

Question 18

Increased capacity for learning

Answer 18

Mammals have larger brains than reptiles and more parts of the brain dedicated to higher brain functions.

Question 19

Internal fertilization & development

Answer 19

Longer, more intense period of growth for offspring, as well as protection. Mammals give birth do live young.

Question 20

Heterodont Dentition

Answer 20

Mammals have an array of different kinds of teeth, allowing them to process a wide variety of foods (reptiels are homodonts). Mammals can exploit more than one kind of niche - an adaptation to dynamic environments.

Question 21

Endothermic

Answer 21

“Warm-blooded” - maintain a constant internal mbody temperature, regardless of external environment. (reptiles are “cold-blooded must strictly regulate activity when sun isn’t available). Endothermy allows adaptation to many habitats and environmental changes.

Question 22

Adaptive Radiation

Answer 22

The process of large-scale expansion of species into new ecological niches, over a relatively short period of time.

Question 23

Definition of evolution (by adaptive radiation)

Answer 23

A species, or group of species, will diverge into as many variations as the following will allow:

1. It’s adaptive potential ( how much a species can adapt and how quickly, and…
2. The adaptive opportunities of the available niches (the availability and diversity of resources need for life such as food, water, shelter, and space).

Question 24

Gradualism

Answer 24

This view emphasizes that change accumulates gradually in which there would be finely graded transitional differences (intermediary steps) between each ancestor and its descendants.

Question 25

Punctuated Equilibrium

Answer 25

This view emphasizes that evolutionary changes isn’t always gradual. In some cases, species don’t change or change very little for long periods of time, and then within a relatively short period of time, there will be a “spurt” speciation. The fossil record more closely supports this perspective.