CHAPTER 3 Evolution and Natural Selection

Question 1

the “calendar” for events in Earth history.

descending order: eons, eras, periods, epochs, and ages

Answer 1

geologic time scale

Question 2

GTS

largest intervals of geologic time
hundreds of millions of years in duration

–the most recent and began more than 500 million years ago

Answer 2

Eons
Phanerozoic Eon

Question 3

GTS

the second longest portions of geological time
divided time intervals of eons
subdivided by periods

Answer 3

era

Question 4

The enumeration of those geologic time units is based on—-, which is thecorrelationand classification of rock strata

GTS is also divided using significant events in the history of the Earth (e.g. dominant life forms, extinction events, climate)

Answer 4

stratigraphy

Question 5

Impotance of GTS

• In exploration and —– (geologically date range specific).
• Study of fossils allows us to —- of organisms that lived billion years ago.

Answer 5

retrieval of fossil fuels
visualize the characteristics

Question 6

Evolution

In biology, EVOLUTION is the change in the characteristics of a species over several generations and relies on the process of natural selection.

EVOLUTION is a process that results in changes in the genetic make up (gene pool) of a population through successive generations.

Question 7

Evolution: a Product and Process

—-is genetic change that occurs over long time scales, resulting in large changes in heritable traits in a population; changes large enough that we consider this population a unique taxonomic group, or species
—is genetic change that occurs over small time scales and results in small changes in heritable traits

Answer 7

macroevolution
microevolution

Question 8

Evolution is a product of two opposing forces:

1. Processes that constantly introduce variation in traits
2. Processes that make particular variants become more common or rare.

Answer 8

P = G + E + (G X E)

Question 9

What causes variations?

Answer 9

Recombination
Mutation

Question 10

How does variations occurs?

During fertilization, sperm cell fuses with the ovum to create a —.

Each chromosome contains hundreds to thousands of genes

On each pair of chromosomes, there are two genes that determine that trait to be inherited. This gene pair is called —.

Answer 10

zygote
allele

Question 11

Mechanisms of Evolution

Change in the DNA sequence within a gene or chromosome of a living organism
It can be the result of viral infection, exposure to mutagens, or mistakes in DNA replication during cell division.

Answer 11

mutation

Question 12

Mutation

—- mutations can lead to the reproductive success and adaptability of an organism to its environment

—– mutations reduce the fitness of an organism and increase the susceptibility to several illnesses and disorders.

Answer 12

Beneficial
Deleterious

Question 13

Classifications of Mutations

Germ line mutationsoccur in gametes (eggs or sperm cells) and — to offspring.

Somatic mutationsoccur in non-reproductive cells and are not pass on to the following generation

Answer 13

can be pass on

Those mutations that occur in germ line are the most important to large-scale evolution because they can be transmitted to offspring.

Question 14

Mechanisms of Evolution

It leads to an evolutionary change when some individuals with certain traits in a population have a higher survival and reproductive rate than others and pass on these inheritable genetic features to their offspring.

Answer 14

natural selection

Question 15

Natural Selection

— is a process in which the individual is subjected to.

—is a measure of how well organismssurviveandreproduceduring this process of natural selection, with emphasis on “reproduction“. Survivalis one important component of fitness.

Answer 15

Selection
Fitness

Fitness also depends on the ability of the organism to attract a mate andreproduceto make fertile offspring. An organism that survived for many years, but never successfully attracted a mate or had offspring, would have very low (zero) fitness.

Question 16

— (1809–1882) and — (1823–1913) independently proposed the concept of natural selection as a mechanism for biological evolution.

Answer 16

Charles Darwin
Alfred Russel Wallace

Question 17

Categories of Natural Selection

occurs when the environment selects average against organisms of a population with extreme versions of a trait.

• favors an average phenotype by selecting against extreme variation.

Answer 17

stabilizing selection

Question 18

Categories of Natural Selection

the environment selects for an extreme characteristic

• single phenotype is favored, causing the allele frequency to continuously shift in one direction

Answer 18

directional selection

Predation
Human hunters or fishermen pursuing quarry most often kill the bigger individuals
Super bugs

Question 19

Categories of Natural Selection

the environment favors extreme traits in a population at the expense of intermediate forms, thereby splitting the population into two or more subpopulations.

- selection often drives speciation

Answer 19

disruptive selection

Disruptive selection happens in large populations with lots of pressure for the individuals to find advantages or niches as they compete with each other for food to survive and/or partners to pass on their lineage.

Question 20

Mechanisms of Evolution

The flow of alleles in and out of a population due to the migration of individuals or gametes.

This variable flow of individuals in and out of the group not only changes the gene structure of the population, but can also introduce new genetic variation to populations in different geological locations and habitats.

Answer 20

gene flow

Question 21

Mechanism of Evolution

It can occur when a small group of individuals leave in a population and establishes a new one in a geographically isolated region.

It is random as it occurs in a result of pure chance, however, it affects small populations significantly unlike large populations that are not susceptible to change due to chance.

Answer 21

genetic drift

bottle neck effect and founder effect

Question 22

genetic drift

A dramatic decrease in genetic diversity caused by the formation of isolated small colony of individuals.
The distance or obstacles between the two populations make interbreeding impossible, and the new populations become genetically distinct over time.
A mutation may cause a population of organisms to become reproductively isolated from the parent foundation. Without the ability to interbreed with the larger population, the small population becomes distinct. If successful it will grow into a new species.

Answer 22

founder effect

Endogamy (marrying within the religion)
Polygyny (the practice of taking several wives)

Question 23

genetic drift

A genetic drift resulting from the reduction of a population due to natural hazards (earthquakes, floods, fires)
When most members of a population die suddenly,genetic variationgoes down and the frequencies at which differentallelesare found in the population can change in a big way..

Answer 23

bottle neck effect

Question 24

How Do Geological Processes and Climate Change Affect Evolution?

First, the locations of continents and oceanic basins greatly influence the earth’s —- and thus help determine where plants and animals can —.

Second, the movement of continents has allowed species to —-, adapt to new environments, and form —- species through natural selection.

The long-term climate changes have a major effect on biological evolution by determining where different types of plants and animals can survive and thrive and by changing the — of different types of ecosystems

Answer 24

climate
live
move
new
locations

Question 25

is any heritable trait that enables an individual organism to survive through natural selection and to reproduce more than other individuals under prevailing environmental conditions.
The trait must also lead to differential reproduction, which enables individuals with the trait to leave more offspring than other members of the population leave.

Answer 25

adaptation/ adaptive trait

Question 26

Adaptation can be:

— (body covering, shape, defensive and offensive armaments)
— (making venom, secreting slime, phototropism)
— (searching for food, mating, vocalizations)

Answer 26

Structural
Physiological
Behavioral

Question 27

How does species richness affect an ecosystem?

According to the first hypothesis, the —. Because of greater variety of producer species, an ecosystem will produce more plant biomass, which in turn will support a greater variety of consumer species.

Answer 27

more diverse an ecosystem is, the more productive it will be

Question 28

Describes the role of anorganismplays in a community.

It is a species’ way of life in a community and includes everything that affects its survival and reproduction

Answer 28

ecological niche/ niche

Question 29

have broad niches.
They can live in many different places, eat a variety of foods, and often tolerate a wide range of environmental conditions.

Answer 29

generalist species

Question 30

occupy narrow niches.
They may be able to live in only one type of habitat, use one or a few types of food, or tolerate a narrow range of climatic and other environmental conditions.

Answer 30

specialist species

Question 31

— species are those species that normally live and thrive in a particular ecosystem.

— species are species that migrate into or are deliberately or accidentally introduced into an ecosystem.
-It is also referred to as invasive, alien, or exotic species

Answer 31

Native
Nonnative

Question 32

Species that provide early warnings of damage to a community or an ecosystem are called —

Answer 32

indicator species.

Question 33

complete disappearance of a species from Earth.
(geneticinbreeding, poorreproduction, decline inpopulationnumbers)

Endemic species are especially vulnerable to extinction

Answer 33

extinction