Unit 3 Test Review - Evolution

Question 1

3.8-3.5 billion years ago

Answer 1

Prokaryotic cells first appear in the fossil record

Question 2

3.5 billion years ago

Answer 2

Fossils of primitive cyanobacteria first appear in the fossil record

Question 3

2.5-2.0 billion years ago

Answer 3

Eukaryotic cells first appear in the fossil record (these were the cells that made organisms more complex)

Question 4

1.5 billion years ago

Answer 4

Multicellular eukaryotic organisms first appear in the fossil record

Question 5

590 million years ago

Answer 5

Bilateral invertebrate animals first appear in the fossil record

Question 6

543 million years ago

Answer 6

Shelled animals first appear in the fossil record

Question 7

533-525 million years ago

Answer 7

Cambrian explosion creates diverse animal life

Question 8

520 million years ago

Answer 8

First vertebrates; first land plants

Question 9

450 million years ago

Answer 9

Large terrestrial colonization by plants and animals

Question 10

400 million years ago

Answer 10

Seed plants first appear in the fossil record; tetrapods and insects first appear in the fossil record

Question 11

300 million years ago

Answer 11

Reptiles first appear in the fossil record

Question 12

225 million years ago

Answer 12

Dinosaurs and mammals first appear in the fossil record

Question 13

160 million years ago

Answer 13

Birds first appear in the fossil record

Question 14

135 million years ago

Answer 14

Flowering plants first appear in the fossil record

Question 15

7 million years ago

Answer 15

Hominids first appear in the fossil record

Question 16

Explain Aristotle’s theory of evolution

Answer 16

-Believed that all organisms that ever would exist were already created
-These organisms were permanent and perfect, thus would not change
-Creator who formed the entire universe

Question 17

Explain Hutton’s theory of evolution

Answer 17

-Geologist, one of the first people to challenge the notion that Earth was young
-Proposed that rock formations are continually formed by molten material being forced up to the Earth’s surface to form rock, where it is eroded away
-The sediment from the erosion is washed into the sea and eventually compacts to form sedimentary rock
-Studied the rates of present-day erosion and sedimentation and the thickness of bands of sedimentary rock
-Concluded that it must have taken millions of years, not thousands, to form the current landscapes

Question 18

Explain Leclerc/Buffon’s theory of evolution

Answer 18

-Noted similarities between humans and apes and speculates that they might have a common ancestor, suggesting species change over time

Question 19

Explain Cuvier’s theory of evolution

Answer 19

-Largely credited with developing the science of paleontology (the study of ancient life through examination of fossils)
-Found that each stratum (layer of rock) is characterized by a unique group of fossil species, the deeper (older) the stratum, the more dissimilar the plant and animal life are from modern life
-He found evidence that new species appeared and others disappeared over time
-CATASTROPHISM: Cuvier proposed the idea that Earth experienced many destructive natural events in the past, where these events (revolutions) were violent enough to have killed species each time they occurred, and species from a nearby area would repopulate these areas - he used this to explain the appearance of new species in the fossil records of a region

Question 20

Explain Lyell’s theory of evolution

Answer 20

-Principles of Geology, rejected catastrophism
-He proposed, based on the work of Hutton, that geological processes operated at the same rates in the past as they do today in a process called UNIFORMITARIANISM
-Slow, continuous, subtle processes could happen over a long period and could result in substantial changes

Question 21

Explain Lamarck’s theory of evolution

Answer 21

-Species increased in complexity over time, until they achieved a level of perfection
-Organisms would become progressively better adapted to their environment
-Body parts that were used extensively to cope with conditions in the environment would become larger and stronger (USE&DISUSE)
-Proposed that characteristics acquired during an organism’s lifetime (such as short hair, and large muscles) could be passed to offspring (INHERITANCE OF ACQUIRED CHARACTERISTICS)
-Though incorrect, visionary because it suggests that adaptation to the environment plays a role in evolution (giraffes stretched necks to reach higher foliage, long necks passed down)

Question 22

Explain Malthus’ theory of evolution

Answer 22

-All living organisms could increase exponentially if allowed to reproduce unchecked (population checks exist), however eventually a population is reduced due to starvation, disease..
-Populations grow faster than their food supply

Question 23

What are the four parts of Darwin’s theory of evolution:

Answer 23

1) Genetic Variation: desirable characteristics must be passed
2) Overproduction of Offspring: individuals produce more than can survive
3) Struggle for existence: excess results in competition for space and food
4) Differential survival and reproduction: individuals with traits best suited to the environment will survive over time and reproduce to pass on these valuable traits (leads to gradual adaptation over time)

Question 24

Artificial Selection

Answer 24

Directed breeding in which individuals that exhibit a particular trait are chosen as parents of the next generation; it is used to produce new breeds or varieties of plants and animals

Question 25

What are the evidences of evolution?

Answer 25

-fossil record & vestigial structures -biogeography -anatomy (homologous and analogous structures) -embryology -molecular biology (DNA)

Question 26

Explain fossil records and vestigial structures *evidence for evolution

Answer 26

-Fossils in younger (closer to surface) rock are more similar to current species than those in deeper strata -Fossils appear in chronological order, and probable ancestors of a species are found in older rocks -Not all organisms appear in the fossil record at the same time, showing the successive evolution of groups (kingdoms of species) -Transitional fossils show an intermediary link between past and present groups of organisms VESTIGIAL STRUCTURES: reduced versions of what were once functional structures in an ancestral species. A key piece of evidence of a fossil record that shows the once functional use of a present-day vestigial structure.

Question 27

Explain biogeography *evidence for evolution

Answer 27

-The study of the past and present geographical distribution of organisms, Darwin and Wallace supported their theories with biogeographical evidence showing that species evolved in one location and spread out to other regions. -Geographically close environments are more likely to be populated by related species -Animals found on islands often closely resemble animals on the nearest continent -Fossils of the same species can be found on the coastlines of neighbouring continents

Question 28

Explain anatomy (homologous and analogous structures) *evidence for evolution

Answer 28

-The study of anatomy provides the evidence of homologous and analogous structures Homologous structures: those that have similar structural elements and origin but may have a different function. They originate from a common ancestor. Analogous structures: do not have common evolutionary origins but perform similar functions. These provide evidence for adaptation to suit the environment.

Question 29

Explain embryology *evidence for evolution

Answer 29

-The study of pre-birth stages of an organism's development. It has been used to determine evolutionary relationships between animals. -Generally, related species share common embryological stages and timings of structural development

Question 30

Explain molecular biology (DNA) *evidence for evolution

Answer 30

-Evolutionary relationships are reflected in DNA since DNA carries genetic information from generation to generation -Species that have similar DNA share a common ancestor -DNA evidence supports conclusions about relationships and common ancestry provided by other areas of evidence

Question 31

Macroevolution / Speciation

Answer 31

The formation of new species from existing species. Two populations become reproductively isolated over time if there is little or no gene flow between them. Without gene flow, the populations may become different species.

Question 32

Microevolution

Answer 32

The change in percentages or frequencies of alleles within populations. These are the small events that lead to evolution within a population.

Question 33

What are the six processes in which allele frequencies in a population change within microevolution?

Answer 33

-mutation -gene flow (migration) -non-random mating -genetic drift (including founder effect and bottleneck effect) -natural selection (directional, stabilizing, or disruptive selection) -sexual selection

Question 34

What are mutations? *microevolution allele frequencies changing in population

Answer 34

-Permanent change in a cell's DNA, ranging from changes in a single base pair to deletions of large sections of chromosomes, can be beneficial, neutral, or harmful -The more genetic variation there is in a population, the greater the genetic diversity of the population and the greater the chance of a selective advantage to some individuals in a changing environment -Mutations are the source of genetic variation, and thus the evolutionary factor

Question 35

What is gene flow (migration)? *microevolution allele frequencies changing in population

Answer 35

-Movement of genes across two different populations, migration -Gene flow describes the net movement of alleles from one population to another as a result of the migration of individuals

Question 36

What is non-random mating? *microevolution allele frequencies changing in population

Answer 36

-Mating among individuals based on a particular phenotype or due to inbreeding. In animals, individuals may choose mates based on their physical or behavioural characteristics. This will affect the alleles in the gene pool of the next generation. -Inbreeding occurs when closely related individuals breed. This can occur naturally or by human-led breeding programs. -In nature, plants self-fertilize, this increases the expression of harmful recessive alleles -Breeding programs attempt to select for a particular desirable trait, this pure-breeding often results in health problems in animals

Question 37

What is genetic drift? *microevolution allele frequencies changing in population

Answer 37

-The change in frequencies of alleles due to random events in a small breeding population, the smaller the population the less likely it is that the parent gene pool will be reflected in the next generation -The change in a population can be regarded in many situations (bottleneck effect, founder effect, variations, endangered species, natural disaster)

Question 38

What is the founder effect, within genetic drift? *microevolution allele frequencies changing in population

Answer 38

-New populations in areas like islands are formed by only a few individuals or founders. These founders carry some but not all of the alleles from the original population's gene pool. They may also not be typical of the population they came from. The gene pool is reduced.

Question 39

What is the bottleneck effect, within genetic drift? *microevolution allele frequencies changing in population

Answer 39

-If a population is reduced by starvation, disease, or a natural catastrophe, the surviving population likely only has a fraction of the alleles that were present before the population decline -The gene pool will have lost its diversity and the allele frequencies will have changed.

Question 40

What is natural selection? *microevolution allele frequencies changing in population

Answer 40

-Selective forces such as competition and predation affect populations. Some individuals are more likely to survive and reproduce than others. Alleles that are selected for by environmental conditions will increase in frequency over time.

Question 41

What are the three types of natural selections regarding allele frequencies changing over time in microevolution?

Answer 41

-Stabilizing selection: favours an intermediate phenotype and acts against extreme variants of this phenotype. This improves the adaptation of the population to aspects of the environment that remain fairly constant. (distribution gets narrow) -Directional selection: favours the phenotypes at one extreme over the other. This selection is common during times of environmental change or when a population migrates to a new habitat. (peak shifts) -Disruptive selection: favours two extremes of a population, and as a result intermediate phenotypes can be eliminated from the population. (two peaks form)

Question 42

What is sexual selection? *microevolution allele frequencies changing in population

Answer 42

-Involves the competition between males through combat or visual displays. It also includes the choices females make in mates. -Some animal species are sexually dimorphic, where the males and females look markedly different and this also contributes to competition and choice -Sexual selection changes the allele frequencies of the population

Question 43

What are the outcomes of sexual selection? *microevolution allele frequencies changing in population

Answer 43

-Speciation through adaptive radiation after geographical isolation -Speciation through genetic drift after a bottleneck effect -Species endangerment and/or extinction due to insufficient genetic diversity from population isolation

Question 44

What are the two reproductive isolating mechanisms within macroevolution?

Answer 44

Pre-zygotic and Post-zygotic

Question 45

What are pre-zygotic isolating mechanisms within macroevolution?

Answer 45

-These mechanisms either impede mating between species or prevent fertilization of the eggs if individuals from different species do mate The mechanisms can prevent mating: -Behavioural isolation -Temporal isolation -Ecological/habitat isolation The mechanisms can prevent fertilization: -Mechanical Isolation -Gametic Isolation

Question 46

Explain each of the pre-zygotic isolating mechanisms within macroevolution

Answer 46

Prevent mating: Behavioural isolation: any signals/behaviours that are species-specific prevent interbreeding with closely related species Temporal isolation: two species occupy the same habitat and have timing barriers Habitat/ecological isolation: two species live in the same general region but in different habitats, so rarely encounter one another Prevent fertilization: Mechanical isolation: two closely related species may attempt to mate but are unsuccessful due to anatomical incompatibility Gametic isolation: gametes from two different species may meet but do not fuse to form a zygote

Question 47

What are post-zygotic isolating mechanisms within macroevolution?

Answer 47

-In rare cases, the sperm and egg of different species produce a zygote. Post-zygotic isolating mechanisms prevent such hybrids from developing into viable, fertile individuals. Thus, the original parental species are proven to be separate species, according to the definition of species. Prevents hybrids: -Zygotic mortality -Hybrid inviability -Hybrid infertility

Question 48

Explain each of the post-zygotic isolating mechanisms within macroevolution

Answer 48

Prevent hybrids: Zygotic mortality: mating and fertilization are possible, but genetic differences result in a zygote that is unable to develop properly Hybrid inviability: a hybrid individual develops but either dies before birth or, if born alive, cannot survive to maturity Hybrid infertility (sterility): The hybrid offspring remain healthy and viable but are sterile, representing a reproductive barrier

Question 49

How does speciaiton occur?

Answer 49

Once an isolating mechanism has prevented gene flow, populations must remain genetically isolated from each other for speciation to occur.

Question 50

What are the two types of speciation, explain them

Answer 50

Sympatric speciation: -occurs when populations that live in the same habitat diverge genetically and become reproductively isolated -more common in plants than animals, chromosomal changes in plants or non-random mating in animals alters gene flow -this result is reproductive incompatibility without geographical isolation Allopatric speciation: -occurs when populations are separated by a geographical barrier and diverge genetically -this speciation occurs when a population is split into two or more isolated groups by a geographical barrier -Eventually, the gene pool of the split population becomes so distinct that the two groups are unable to interbreed when re-introduced

Question 51

What is polyploidy

Answer 51

This can lead to the formation of new species through sympatric speciation

Question 52

What is adaptive radiation (geographic isolating mechanism)

Answer 52

Occurs when a single species evolves into a number of distinct but closely related species, and each new species fills a variety of formerly empty ecological niches

Question 53

What is divergent evolution?

Answer 53

A pattern of evolution in which species that were once similar to ancestral species diverge, or become increasingly distinct. In other words, as a population they adapt, and they become less and less alike

Question 54

What is convergent evolution?

Answer 54

A pattern of evolution in which similar traits arise because different species independently adapted to similar environmental conditions

Question 55

What is mimicry?

Answer 55

Another type of species adaptation that occurs when a harmless species resembles a harmful species in colouration or structure

Question 56

What are the two models that have been proposed to explain the speed at which evolution occurs?

Answer 56

-Gradualism -Punctuated Equilibrium

Question 57

Explain gradualism according to evolutionary change

Answer 57

-view evolutionary change as slow and steady before and after a divergence -supported since Darwin's time

Question 58

Explain punctuated equilibrium according to evolutionary change

Answer 58

-views evolutionary history as long periods of stasis, or equilibrium that are interrupted by periods of divergence -proposed in 1972 by Niles Eldredge and Stephen Jay Gould

Question 59

Explain the impact of human activities on evolution

Answer 59

-have had a great impact on speciation, population decline, and extinction as human activities essentially isolate populations -some human-made barriers are resulting in allopatric speciation such as the conversion of wilderness into cropland, the development of areas for tourism, and the building of urban subdivisions/ roads

Question 60

Where did life emerge from according to evolution?

Answer 60

Chemistry

Question 61

What were the two things needed for early life according to evolution?

Answer 61

a cell membrane, and genetic material

Question 62

What is RNA made up of?

Answer 62

a sugar, a base, and a phosphate

Question 63

What did John Sutherland figure out?

Answer 63

-the intermediate step was needed to form the basics of nucleotides, he used a hybrid (sugar and half a base that came together by evaporation and precipitate from the sky to meet the other,and needed to combine in a warm pond environment, making a ribonucleotide C, exposing this to sunlight helped scientists find the natural pathway to make ribonucleotide U's bringing steps closer to making RNA, and essential component of life.

Question 64

How long did life exist on Earth before anything remotely resembling human beings showed up?

Answer 64

4 billion years

Question 65

When did humans start wearing clothes?

Answer 65

170 thousand years ago

Question 66

When did humans start living in dwellings?

Answer 66

500 thousand years ago

Question 67

When did humans start using fires?

Answer 67

800 thousand years ago

Question 68

When did humans lose body hair?

Answer 68

3 million years ago

Question 69

When did humans start tool-making?

Answer 69

3.3 million years ago

Question 70

Explain mass extinctions

Answer 70

The environment has a strong influence on extinction, selective pressure of the environment produces new species, but they can also cause extinction. The general trend is usually an increase, but in total, it has caused 5 mass extinctions. Mass extinctions decrease the number of species, however, they can also allow for adaptive radiation of surviving species that evolve into new species. The general trend is overall an increase in species throughout Earth's history.

Question 71

Species (Evolution)

Answer 71

a group of organisms that can interbreed and produce fertile offspring

Question 72

Cladistics

Answer 72

a method of classifying organisms by the characteristics they have in common

Question 73

Clade

Answer 73

a group that includes a common ancestor and all the descendants (living and extinct) of that ancestor

Question 74

Cladogram

Answer 74

- a diagram showing evolutionary relationships -it is assumed that the more characteristics the two organisms share, the more recently they diverged from a common ancestor - we use cladograms to examine the relationships between different species

Question 75

Primate

Answer 75

a group of relatively large-brained, mostly arboreal mammals that includes prosimians, monkeys, apes, and humans

Question 76

Anthropoid

Answer 76

the group of primates that includes monkeys, apes, and humans

Question 77

Hominid

Answer 77

all species descended from the most recent common ancestor of chimpanzees and humans that are on the human side of the lineage

Question 78

Alfred Russel Wallace

Answer 78

Outlined his theory of evolution identical to Darwins, but Darwins released his first

Question 79

Natural Selection

Answer 79

the way in which nature favours the reproductive success of some individuals within a population over others

Question 80

Adaption

Answer 80

a characteristic or feature of a species that makes it well-suited for survival or reproductive success in its environments

Question 81

Four parts of a theory

Answer 81

Observations, laws, hypotheses, inferences

Question 82

Evolution

Answer 82

the scientific theory that describes changes in species over time and their shared ancestry

Question 83

Fact vs Theory vs Hypothesis

Answer 83

A fact is proven to be true, supported by evidence, and has been verified through observation and experiments Theory is an explanation of a collection of facts and observations, supported by a large body of evidence and is comprehensive enough to explain them A hypothesis is an educated and proposed explanation that is tentative to prior limited knowledge

Question 84

Neutral mutation

Answer 84

mutation that doesn't result in a selective advantage or disadvantage

Question 85

Harmful mutation

Answer 85

a mutation that reduces the reproductive success of an individual, does not accumulate over time, it is selected against

Question 86

Beneficial mutation

Answer 86

a mutation that increases the reproductive success of an individual, beneficial mutations are favoured by natural selection and accumulate over time

Question 87

Artificial selection

Answer 87

directed breeding in which individuals that exhibit a particular trait are chosen as parents of the next generation, used to produce new breeds of plants and animals