Chapter 20

Question 1

Study of evolutionary relationships. The evolutionary history of a species or group of related species. The evolutionary history and relationship of an organism or a group of organisms it may have evolved, or to which species it is most closely related. Provide information on shared ancestry but not necessarily on how organisms are similar or different.

Answer 1

Phylogeny

Question 2

How we classify organisms or put them into groups. Classifies organisms and determines their evolutionary relationship.
ex.) data from fossils, body part structures, molecules from organisms, and DNA analysis.

Answer 2

Systematics

Question 3

Is the ordered division and naming of organisms. Science of naming and dividing organisms. “arranged law.” Th science of classifying organisms to construct internationally shared classification systems with each organism placed into increasingly more indusive grouping.
Ex.) grocery store organization. On large space is divided into departments, then each department further divides into isles, then each aisle into categories and brands, and then finally into a single product.

Answer 3

taxonomy

Question 4

The two-part scientific name of a species is called a what? How scientists refer to an organism by its genus and species.

Answer 4

binomial

Question 5

What are the three options of domains in a hierarchical classification system?

Answer 5

Domain: Eukarya, Bacteria, and Archaea

Question 6

What is the correct order of the taxonomic groups of hierarchical classification system?
What are the names at each level known as?

Answer 6

Domain –> Kingdom–> Phylum–> Class–> Order–> Family –> Species
( Do Kids Prefer Candy Over Fresh Green Spinach)

-Taxons

Question 7

Systematics depict evolutionary relationships in branching these. Show the evolutionary pathways and connections among organisms. A diagram used to reflect evolutionary relationships among organisms or groups of organisms. “tree of life” to illustrate when different organisms evolved and to show the relationship among different organisms. These will continue to change as researchers discover new types of life and learn new info.

Answer 7

phylogenetic trees

Question 8

Phenotypic and genetic similarities due too ancestry. Organisms with similar morphologies or DNA sequences are likely to be more closely related. Features that overlap morphologically (in form) and genetically as this. Stem from developmental similarities that are based on evolution.
ex.) bones in bats and bid wings have these.
More grouped bones arranged in a similar way. The more complex, the more likely an overlap due to common evolutionary past.

Answer 8

Homologies

Question 9

These are determined based on the degree of similarity in nucleotide sequence between taxa

Answer 9

Homologies

Question 10

When similar characteristics occur because of environmental constraints and not due to a close evolutionary relationship.
ex.) insects use wings to fly like bats and birds, but the wing structure and embryonic origin is completely different. the bird and bat wings are homologous because the bones are inherited from a common ancestor, while the wings themselves are these as they evolve independently.

Answer 10

analogous (homoplasy)

Question 11

Homologous and Analogous.
- Homologous: shared by similar embryonic origin.
- Analogous: have a similar function
ex.) the bones in a whale’s front flipper are homologous to the bones in the human arm. These structures are not analogous. A butterfly or bird’s wings are analogous but not homologous.

Question 12

Limitations of Phylogenetic Trees:

Answer 12

• It is possible for the 2 groups to appear more different than the other groups that are not closely related.
• Only show the order in which things took place. Branches do not account for length of time, only evolutionary order
• New branches from a tree form.. groups that are not closely related, but evolve under similar conditions, may appear more phenotypically similar to each other than to close relative

Question 12

Occurs when similar environmental pressures and natural selection produce similar (analogous) adaptations in organisms from different evolutionary lineages.

Answer 12

Convergent Evolution

Question 13

After scientists sort the homologous and analogous traits, they often organize the homologous traits using this. Classifies organisms by common descent.

Answer 13

Cladistics

Question 14

A group of species that includes an ancestral species and all its descendants. Groups of organisms that descended from a single ancestor.

Answer 14

Clade

Question 15

A characteristic found in the ancestor of a group. All of the organisms in the taxon or clade have that trait. A character that originated in an ancestor of the taxon.

Answer 15

Shared ancestral character

Question 16

This trait is derived at some point but does not include all of the ancestors in the tree. An evolutionary novelty unique to a particular clade.

Answer 16

Shared derived character

Question 17

Uses constant rates of evolution in some genes to estimate the absolute time of evolutionary change. The number of nucleotide substitutions in related genes is assumed to be proportional to the time since they last shared a common ancestor.

Answer 17

Molecular Clock

Question 18

The movement of genes from one genome to another. Ex.) mrsa or antibiotic resistance.. don’t want this transfer to good bacteria

Answer 18

Horizontal gene transfer

Question 19

Reveals changes in the history of life on Earth. The relative ages of fossils can be determined by their sequence in the rock strata. The absolute ages of fossils can be determined by radiometric dating. Each isotope has a known half-life (the time required for half the parent isotope to decay)

Answer 19

Fossil Record

Question 20

The oldest known fossils. Rocks formed by the accumulation of sedimentary layers on bacterial mats. Date back to 3.5 billion years ago.

Answer 20

Stromatolites

Question 21

Earth’s apparent age is what?

Answer 21

4 billion years

Question 22

How old is eukaryotes?

Answer 22

1.8 billion years old

Question 23

How old are prokaryotes? Prokaryotes were Earth’s sole inhabitants for more than 1.5 billion years.

Answer 23

3.5 billion years old

Question 24

Scientists believe there were how many mass extinctions? Which one are we in right now?

Answer 24

There were 5, we are in the 6th now
- In each of the 5 mass extinction events, 50% or more of MARINE species became extinct

Question 25

Early prokaryotes released oxygen into the atmosphere through the process of photosynthesis. The increase in atmospheric oxygen that began 2.4 billion yrs ago led to the extinction of many organisms. The eukaryotes flourished in the oxygen-rich atmosphere and gave rise to multicellular organisms.

Answer 25

Origin of Eukaryotes

Question 26

The Origin of New Groups of Organisms

Mammals belong to the group of animals called what?
- The evolution of unique mammalian features can be traced through gradual changes over time.

Answer 26

tetrapod

Question 27

The history of life on Earth has seen a rise and fall of many groups of organisms. The rise and fall of groups depend on what 2 rates within the group?

Answer 27

speciation and extinction

Question 28

Is a Six Mass Extinction Under Way?

Answer 28

Scientists estimate that the current rate of extinction is 100-1,000 times the typical background rate. Extinction rates tend to increase when global temperatures increase. Data suggest that a sixth, human-caused mass extinction is likely to occur unless dramatic action is taken.

Question 29

The fossil record shows that most species that have ever lived are now what?

Answer 29

extinct

Question 30

Can be caused by changes to a species’ environment. It is a process in which new forms arise by the slight modification of existing forms.

Answer 30

extinction

Question 31

At times, the rate of this has increased dramatically and caused this. It is the result of disruptive global environmental changes.

Answer 31

Mass Extinction

Question 32

Can alter ecological communities and the niches available to organisms. It can take 5-100 million years for diversity t recover following a mass extinction. The type of organisms residing in a community can change with this.

Answer 32

Mass Extinction

Question 33

The evolution of many diversely adapted species from a common ancestor.

Answer 33

Adaptive Radiations

Question 34

Adaptive Radiations may follow:

Answer 34

• Mass Extinctions
• The evolution of novel characteristics
• Colonization of new regions

Question 35

An evolutionary change in the rate or timing of developmental events. it can have a significant impact on body shape.

Answer 35

Heterochrony

Question 36

What is used to determine phylogeny?
a.) mutations
b.) DNA
c.) evolutionary history
d.) organisms on earth

Answer 36

c.) evolutionary history

Question 37

What do scientists in the field of systematics accomplish?
a.) discover new fossil sites
b.) organize and classify organisms
c.) name new species
d.) communicate among field biologists

Answer 37

b.) organize and classify organisms

Question 38

Which statement about the taxonomic classification system is correct?
a.) There are more domains than kingdoms.
b.) Kingdoms are the top category of classification.
c.) Classes are divisions of orders.
d.) Subspecies are the most specific category of classification.

Answer 38

d.) Subspecies are the most specific category of classification.

Question 39

Which statement about analogies is correct?
a.) They occur only as errors.
b.) They are synonymous with homologous traits.
c.) They are derived by similar environmental constraints.
d.) They are a form of mutation.

Answer 39

c.) They are derived by similar environmental constraints.

Question 40

What do scientists use to apply cladistics?
a.) homologous traits
b.) homoplasies
c.) analogous traits
d.) monophyletic groups

Answer 40

a.) homologous traits

Question 41

What is true about organisms that are a part of the same clade?
a.) They all share the same basic characteristics.
b.) They evolved from a shared ancestor.
c.) They usually fall into the same classification taxa.
d.) They have identical phylogenies.

Answer 41

b.) They evolved from a shared ancestor.

Question 42

The transfer of genes by a mechanism not involving asexual reproduction is called:
a.) meiosis
b.) web of life
c.) horizontal gene transfer
d.) gene fusion

Answer 42

c.) horizontal gene transfer

Question 43

What does the trunk of the classic phylogenetic tree represent?
a.) single common ancestor
b.) pool of ancestral organisms
c.) new species
d.) old species

Answer 43

a.) single common ancestor