Chapter 9

Question 1

Ancestor versus Cousin

Answer 1

An ancestor is a direct predecessor in a lineage (e.g., a grandparent).
A cousin is a relative descended from a common ancestor, but not in a direct line (e.g., the child of your parent’s sibling)

Question 2

Ancestral Trait

Answer 2

A trait shared by two or more taxa that was inherited from their common ancestor. It is a trait that was present in the past

Question 3

Conserved Trait

Answer 3

A trait that remains relatively unchanged over long periods of evolutionary time. This indicates that the trait is likely essential for survival or function

Question 4

Derived Trait

Answer 4

A trait that is a new variation of an ancestral trait. It is a trait that evolved after the common ancestor of the group being considered.

Question 5

Descendant:

Answer 5

An organism that is related to an ancestor, either directly or indirectly.

Question 6

Molecular Clock

Answer 6

A technique that uses the rate of accumulation of genetic mutations to estimate the time of divergence between two lineages. It relies on the assumption that mutations occur at a relatively constant rate

Question 7

Monophyletic

Answer 7

A group of taxa that includes a common ancestor and all of its descendants. It represents a single branch on the tree of life

Question 8

MRCA (Most Recent Common Ancestor)

Answer 8

The most recent individual or population from which all organisms in a group are directly descended.

Question 9

Neutral Substitution Mutations

Answer 9

Mutations in DNA that do not significantly affect an organism’s fitness. These mutations accumulate at a relatively constant rate, which is the basis for the molecular clock

Question 10

Parsimony:

Answer 10

The principle that the simplest explanation is usually the best.

Question 11

Parsimonious

Answer 11

Characterized by simplicity.

Question 12

Maximum Parsimony:

Answer 12

A method for reconstructing phylogenetic trees that assumes the tree with the fewest evolutionary changes is the most likely.

Question 13

Ockham’s Razor:

Answer 13

The philosophical principle that, among competing hypotheses, the one with the fewest assumptions should be selected.

Question 14

PubMed:

Answer 14

A free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics.

Question 15

Rate

Answer 15

A measure of how quickly something changes over time

Question 16

Shared Derived Character

Answer 16

A derived trait that is shared by two or more taxa. These traits are used to infer evolutionary relationships.

Question 17

Analogy

Answer 17

Similarity of function and/or appearance of structures that are not from common decent. (convergent evolution)

Question 18

Ancestor, Ancestral

Answer 18

A predecessor; relating to a predecessor.

Question 19

Archaea

Answer 19

One of the three domains of life; prokaryotic organisms often found in extreme environments.

Question 20

Bacteria:

Answer 20

One of the three domains of life; prokaryotic organisms.

Question 21

Billions:

Answer 21

A very large number (1,000,000,000).

Question 22

Changes

Answer 22

Alterations or modifications.

Question 23

cdc.gov (Centers for Disease Control and Prevention):

Answer 23

U.S. public health agency.

Question 24

Changes in DNA or RNA bases or in amino acids or proteins or traits:

Answer 24

Mutations, variations

Question 25

Common Ancestry:

Answer 25

The idea that all living organisms share a common ancestor.

Question 26

Conserved

Answer 26

Preserved or unchanged.

Question 27

Constant

Answer 27

Remaining the same over time.

Question 28

Convergent Evolution:

Answer 28

The independent evolution of similar traits in unrelated lineages.

Question 29

DNA → RNA → Amino Acids → Protein → Trait

Answer 29

The central dogma of molecular biology.

Question 30

Domain

Answer 30

The highest level of biological classification (Archaea, Bacteria, Eukarya)

Question 31

Eukarya:

Answer 31

One of the three domains of life; organisms with cells containing a nucleus.

Question 32

Evidence:

Answer 32

Data or information that supports or refutes a claim

Question 33

Extant

Answer 33

Currently living.

Question 34

Extinct

Answer 34

No longer living.

Question 35

Fitness

Answer 35

The ability of an organism to survive and reproduce.

Question 36

GenBank

Answer 36

A public database of genetic sequences.

Question 37

Gene Flow

Answer 37

The movement of genes between populations.

Question 38

Homology

Answer 38

Similarity of structures due to common ancestry.

Question 39

KPCOFGS Classification (Kingdom, Phylum, Class, Order, Family, Genus, Species

Answer 39

The hierarchical system for classifying living organisms. Sub- and super- are used to add more specific classification levels.

Question 40

Line

Answer 40

A lineage or evolutionary pathway

Question 41

Mitochondria:

Answer 41

Organelles within Eukaryotic cells that produce energy.

Question 42

Most Simple:

Answer 42

The least complex.

Question 43

Mutations:

Answer 43

Changes in DNA sequence.

Question 44

Natural Selection:

Answer 44

The process by which organisms with advantageous traits survive and reproduce more successfully.

Question 45

Nonrandom Mating:

Answer 45

When individuals choose mates based on specific traits

Question 46

Nucleotides

Answer 46

The building blocks of DNA and RNA

Question 47

Phenotype:

Answer 47

The observable characteristics of an organism.

Question 48

Phylogeny

Answer 48

The evolutionary history of a group of organisms.

Question 49

Speciation

Answer 49

The process by which new species arise.

Question 50

Taxon

Answer 50

A group of organisms in a classification system.