Natural Selection

Question 1

Primary sources of evidence supporting evolution:

Answer 1

1. The fossil record
2. Comparative morphology
3. Biogeography

Question 2

Fossils and the fossil record

Answer 2

-Traces of past organisms that give a visual of evolutionary change over time
-Can be dated by examining of carbon 14 decay

Question 3

Comparative morphology

Answer 3

Analysis of structures of living and extinct organisms

Question 4

Homology

Answer 4

Characteristics in related species that have similarities even if the functions differ

Question 5

Embryonic homology

Answer 5

Many species have similar embryonic development

Question 6

Vestigial Structures

Answer 6

Structures that are conserved even though they no longer have a use

Question 7

Molecular homology

Answer 7

Many species share similar genetic information

Question 8

Homologous structures

Answer 8

Characteristics that are similar in two species because they share a common ancestor
ex. Arm bones of many species

Question 9

Convergent evolution

Answer 9

Similar adaptations that have evolved in distantly related organisms due to similar environments

Question 10

Analogous structures

Answer 10

Structures that are similar but have separate evolutionary origins
Ex. Wings in birds vs bats vs bees

Question 11

Common ancestry evidence

Answer 11

1. Membrane bound-organelles
2. Linear chromosomes
3. Introns in genes

Question 12

Biogeography

Answer 12

The distribution of animals and plants geographically

Question 13

Systematics

Answer 13

Classification of organisms and determining their evolutionary relationships

Question 14

Taxonomy

Answer 14

Naming and classifying species

Question 15

Phylogenetics

Answer 15

Hypothesis of evolutionary history
-Use phylogenetic trees to show evolution

Question 16

To determine evolutionary relationships, scientists use

Answer 16

-Fossil records
-DNA, proteins
-Homologous structures

Question 17

Phylogenetic trees

Answer 17

diagrams that represent the evolutionary history of a group of organisms, similar to cladograms except trees show the amount of time

Question 18

Cladograms

Answer 18

-Each line represents a lineage
-Each branching point is a node
-Root is the common ancestor of all the species

Question 19

Sister taxa

Answer 19

Two clades that emerge from the same node
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Question 20

Basal Taxon

Answer 20

Lineage that evolved from the root and remains unbranched -

Question 21

Synapomorphy

Answer 21

A derived character shared by clade members
Derived characteristics: similarly inherited from the most recent common ancestor of an entire group
Ancestral characteristics: Similarity that arose prior to the common ancestor

Question 22

Monophyletic group

Answer 22

Includes the most recent common ancestor of the group and all of it’s descendants

Question 23

Paraphyletic group

Answer 23

Includes the most recent common ancestor of the group, but not all of it’s descendants

Question 24

Polyphyletic group

Answer 24

Doesn’t include the most recent common ancestor of all members of the group

Question 25

Species

Answer 25

Group able to interbred and produce viable, fertile offspring

Question 26

Speciation

Answer 26

Formation of a new species

Question 27

Allopatric speciation

Answer 27

-Physical barrier divides pop. or a small pop. is separated from main pop. -Populations are geographically isolated *prevents gene flow *Often caused by natural disasters

Question 28

Sympatric

Answer 28

-New species evolves while still inhabiting the same geographic region as the ancestral species *usually due to the exploitation of a new duty within the population

Question 29

Speciation occurs due to

Answer 29

1. Prezygotic 2. Postzygotic

Question 30

Prezygotic barriers

Answer 30

1. Habitat isolation 2. Temporal isolation 3. Behavorial isolation 4. Mechanical isolation 5. Gametic isolation

Question 31

Habitat isolation

Answer 31

Species live in different areas or they occupy different habitats within the same area

Question 32

Temporal isolation

Answer 32

Species breed at different times

Question 33

Behavioral isolation

Answer 33

Unique behavioral patterns and rituals separate species

Question 34

Mechanical isolation

Answer 34

Reproductive anatomy of one species doesn't work with the anatomy of another species

Question 35

Genetic isolation

Answer 35

Proteins on the surface of the gametes don't allow for sperm and egg to fuse

Question 36

Postzygotic-reduced hybrid viability

Answer 36

genes of different parent species may interact that impair hybrids development or survival

Question 37

Reduced hybrid fertility

Answer 37

Hybrid can develop into a healthy adult, but is sterile

Question 38

Hybrid breakdown

Answer 38

The hybrid of the first generation may be fertile, but when they mate again or with another species offspring will be sterile

Question 39

Microevolution

Answer 39

Change in allele frequencies within a single species or pop

Question 40

Macroevolution

Answer 40

Large evolutionary patterns

Question 41

Punctuated equilibrium

Answer 41

Rapid evolution

Question 42

Gradualism

Answer 42

Slow evolution over hundreds, thousands of years

Question 43

Divergent evolution

Answer 43

Groups with the same common ancestor evolve and accumulate differences resulting in the formation of a new species

Question 44

Adaptive radiation

Answer 44

If a new habitat or niche becomes available, species diversifies rapidly

Question 45

Convergent evolution

Answer 45

Two different species develop similar traits despite having different ancestors

Question 46

Origins of life

Answer 46

-Earth formed 4.6 billion years ago -Life suitable 3.9, fossils found 3.6 *cyanobacteria

Question 47

How did life arise?

Answer 47

Early life contained inorganic molecules, these could have synthesized organic molecules due to free energy and abundant oxygen

Question 48

Miller and Urey hypothesized

Answer 48

Organic molecules served as building blocks for macromolecules

Question 49

RNA world hypothesis

Answer 49

Proposes that RNA could have been the earliest genetic material