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Question 1

The idea of biological evolution was long in coming. Explain.

Question 2

Who was Aristotle?

Answer 2

A Greek Naturalist and great thinker for made keen observations about the world around him. To him nature was organized in a continuous fashion from lifeless matter through complex life forms.

Question 3

What is the scale of nature

Answer 3

Essentially, each life form or species was a separate link in this chain with the “ lowest” life forms at the beginning of the chain extending onward to humans.

Question 4

What is the biogeography? What questions were raised concerning this dicisplin?

Answer 4

A discipline in which the world distribution of plants and animals is studied. The question it raised is “ How did so many species get from the “ center of creation” to islands and other isolated places?

Question 5

What is comparative anatomy? What questions were raised in this disipline?

Answer 5

comparisons of the similarities and differences in the body plans of various groups ( mammals, reptiles, birds, amphibians, fish) are made. Raises many questions about how organisms were made and their body parts and how they don’t have a function. ( ex appendix)

Question 6

What are fossils and how did fossil evidence confuse the issue of evolution?

Answer 6

Fossils are physical evidence of organisms that have lived in the past. It confused the issue of evolution because perhaps species became modified overtime.

Question 7

What is catastrophism? What is associated with this idea?

Answer 7

a geological theory that proposes Earth’s features were primarily shaped by sudden, violent, and short-lived events like massive floods or asteroid impacts, causing significant changes to the landscape and often leading to mass extinctions; this idea is most strongly associated with the French scientist Georges Cuvier, who used fossil evidence to support the theory of catastrophic events shaping Earth’s history.

Question 8

What is gradualism?

Answer 8

the idea that slow but continues processes can eventually add up to big changes. James Hutton.

Question 9

What is uniformitarianism?

Answer 9

refers to Charles lylells idea that geologic processes occurring today are the same processes that occurred in the past, and that these processes happen at the same uniform rate.

Question 10

What is the theory of acquired characteristics? Who is associated with this theory?

Answer 10

Jean-Baptiste Lamarck, If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring. ( ex. the giraffes growing their necks)

Question 11

How do the prevailing beliefs of society influence the interpretation of natural porcesses?

Answer 11

Pre Darwinian: believed the earth was relatively new, species dont changes and the number of species remains constant, adaptation to the environment of the work of a creator. Observations are supposed to support the prevailing world view.
Post Darwinian: The earth is relatively old, species are related by dedendents, adaptation to the environment involves the interplay of random genetic variations and environmental conditions. Observation and experimentation are used to test hypotheses about evolution.

Question 12

Who was Charles Darwin and what was his background?

Answer 12

Set out as a naturalist on a ship. Darwin grew up in a family of doctors and he didn’t care for schooling. Charles dropped out of medical school and instead went to divinity school to try and become a clergy.

Question 13

What are allele frequencies?

Answer 13

the abundance of each kind of allele in a population as a whole. These are usually written in decimal form.

Question 14

Who was Alfred Wallace?

Answer 14

A naturalist and explore who also came up with the idea of evolution individually from Darwin.

Question 15

What are “ missing links”?

Answer 15

a hypothetical animal that is thought to have existed and shared characteristics with both a group of animals and their ancestors, but has not been found in the fossil record

Question 16

What is artificial Selection?

Answer 16

a process where humans choose specific traits in organisms and breed them to pass those traits on to future generations

Question 17

genetic drift

Answer 17

Random change in allele frequencies over the generations as a result of chance. Drift occurs most often in small populations because they have smaller gene pools in the first place.

Question 18

Founder Effect

Answer 18

Occurs when a few individuals break away from a larger population and establish a new population. The gene pool of the new founder population may be quite different from that of a larger population left behind. ( Ex. The Amish and dwarfism)

Question 19

Population Bottleneck

Answer 19

Occurs when disease starvation or some other stressful event wipes out most of a large population. Those few individuals left have a smaller gene pool probably with less variation. These few individuals breed with one another. Alles can be lost during bottleneck events.

Question 20

Directional Selection

Answer 20

allele frequencies shift away from the “ average” and go in one direction. Result is that a trail or traits at one end of the range of variation become more common.

Question 21

Stabilizing selection

Answer 21

Selection in which the most common form of the trai is favored and individuals possessing the extreme traits at each end of the spectrum of variation become fewer in number and may disappear altogether. ( ex. human birth weight)

Question 22

Disruptive Selection:

Answer 22

selection in which both extreme forms in the range of variation are
favored and the intermediate (“average”) forms are selected against. Example: Bird bill size
as related to cracking seeds

Question 23

Balanced Polymorphism

Answer 23

occurs when natural selection maintains two or more alleles over
the generations at frequencies greater than one percent (q = at least 0.01). Ex. Rh- factor,
sickle cell anemia allele.

Question 24

Sexual Dimorphism

Answer 24

ccurrence of phenotypic differences between males and females of a
given species. This is just a complicated way of saying that males and females look different
and are easy to tell apart. Sexual selection is selection in which a trait gives an individual an
advantage in reproductive success. Sexual dimorphism is one outcome of sexual selection.
For example, the fanciest male birds attract the most female mates so there is selection for
having fancy plumage if you are a male bird.

Question 25

Speciation

Answer 25

changes in allele frequencies that are significant enough to mark formation of
daughter species from a parental species

Question 26

Biological Species

Answer 26

one or more populations of individuals that can interbreed under natural
conditions and produce fertile offspring, and that are reproductively isolated from other such
populations

Question 27

Genetic Divergence

Answer 27

buildup of differences in the gene pools of two or more separated
populations (by way of genetic drift, natural selection, mutations, etc.).

Question 28

Isolating Mechanism

Answer 28

any heritable aspect of body form, physiology or behavior that
prevents interbreeding (gene flow) between genetically divergent populations

Question 29

Prezygotic Isolation

Answer 29

Mating is prevented or zygote formation is prevented
a) Temporal isolation: (time) Organisms breed at different times of year (seasons).
b) Behavioral isolation: Organisms have different courtship behaviors.
c) Mechanical isolation: Copulatory (sex) organs don’t fit or are incompatible.
d) Gametic Mortality: gametes of different species are often incompatible and won’t fuse
e) Ecological isolation: potential mates live in different local habitats within some area
and it is unlikely that they would come in contact with one another for mating

Question 30

Postzygotic Isolation

Answer 30

the hybrids formed are infertile or sterile.
a) Zygote mortality: egg is fertilized by the sperm but the zygote or embryo dies
b) Hybrid inviability: hybrid organism is produced but has low fitness (sickly)
c) Hybrid offspring: hybrids are sterile or partially so

Question 31

allopatric Speciation:

Answer 31

other country” This is the most common form of speciation.
Speciation can occur because there is absolutely NO gene flow between populations. The
populations are separated by a geographic barrier such as a canyon, mountain range, ocean or
even something as simple as a freeway or highway. A road is a formidable barrier if you are a
snail for example. Mutations occur in the populations and without gene flow to mix the
alleles among populations, each population can become different through time, possibly so
different that when the populations are brought back together the populations no longer
interbreed. Then they are considered two separate species

Question 32

Sympatric Speciation

Answer 32

“same country” Speciation which occurs rapidly or suddenly
from a small proportion of individuals within an existing population. Usually this type of
speciation is rare, but it is seen among plants that become polyploid (i.e. many complete sets
of chromosomes - more than the usual two sets of chromosomes). When a plant becomes
polyploid (This can happen in one generation.), then the gametes it forms are no longer
compatible with nonpolyploid plant gametes. Effectively, the plants are now two separate
species because they can no longer interbreed.

Question 33

Parapatric Speciation

Answer 33

beside country” Speciation that occurs where populations share a
common border. (Key phrases are: fringe, border, edge, zone of overlap and little gene flow
or almost no gene flow.) Typically, there is a hybrid zone where individuals living in the
zone of overlap breed and produce hybrids. For the most part though, the two populations
don’t mate or interbreed except at the fringe or border areas. Eventually these two
populations may not interbreed at all, not even at the borders or fringes of population overlap.
Then they would be considered two different species rather than two populations of the same
species.

Question 34

Gradualist model of speciation:

Answer 34

peciation occurs gradually as many small changes in form
(via mutations for example) build up over time

Question 35

Punctuated model of speciation

Answer 35

speciation occurs abruptly. There are long periods of no
change that are “punctuated” by short periods of very rapid change. Might see this in relation
to the founder effect and population bottlenecks where there is reduced variation in the gene
pools and therefore the potential for drastic changes.

Question 36

Adaptive Radiation

Answer 36

bursts of microevolutionary (small changes) activity within a lineage.
The result is formation of many new species in a wide range of habitats. Adaptive radiation
occurs when there is an area with many unfilled niches or opportunities for particular “ways
of life.” It’s like being able to exploit brand new territories. The three means of access that
may result in adaptive radiation are
physical access - a lineage of organisms is present when an adaptive zone opens up.
b) evolutionary access - if some body structure or function is modified (via mutation), this
may allow a lineage to exploit the environment in improved or novel ways. Example:
when the 5-toed forelimbs of vertebrates evolved into wings, these vertebrates could now
exploit the skies for flight.
c) ecological access - a lineage can enter an unoccupied adaptive zone or outcompete the
resident species

Question 37

Background Extinction:

Answer 37

expected rate of the inevitable disappearance of species as local
conditions change.

Question 38

Mass Extinction:

Answer 38

an abrupt rise in extinction rates above the background level. These
extinctions are catastrophic global events in which family levels (including all the genera and
species in those families) are wiped out simultaneously

Question 39

Stratification

Answer 39

the layering of sedimentary deposits. (Strata = layers.) As one examines the
fossils contained in the layers, one can develop a picture of what life was like on earth during
a given time period. The oldest layers containing more ancient fossils are at the bottom and
the newest layers containing more recent fossils are on the top

Question 40

Homology

Answer 40

similarity in one or more body parts in different organisms that is attributable
to descent from a common ancestor.

Question 41

Morphological convergence

Answer 41

when two or more unrelated groups develop similar patterns of
body structures because of similar environmental pressures on those groups.

Question 42

Analogy r

Answer 42

refers to the similarity in body parts among distantly related organisms because of
similar environmental pressures.

Question 43

Systematics

Answer 43

a branch of biology that deals with patterns of diversity in an evolutionary
context. Systematics approaches the patterns in three ways: