Chapter 22 - Phylogeny. Fossils, and the History of Life

Question 1

phylogeny

Answer 1

The evolutionary history and relatedness of a group of organisms

Question 2

Phylogenetic tree

Answer 2

A hypothisis about the evolutionary relationships amoung a group of organisms in the form of a branching tree

Question 3

nodes

Answer 3

The fork in the tree were the branch splits

Question 4

Sister groups

Answer 4

A group of species that are more closely related than other groups

Question 5

taxa

Answer 5

the more techincal word for group

Question 6

monphyletic

Answer 6

when all memebers of a grouping share a common ancestor

Question 7

paraphyletic

Answer 7

grouping that includes some but not all of the descendants of a common ancestor

Question 8

polyphyletic

Answer 8

Grouping that does not include the common ancestors of all members

Question 9

Domain

Answer 9

one of the three largest groups of the tree of life: bacteria, archaea, eukarya

Question 10

Kingdom

Answer 10

A group of closely related phyla

Question 11

Phylum

Answer 11

A group of closely related classes

Question 12

Class

Answer 12

A group of closely related orders

Question 13

Order

Answer 13

A group of closely related families

Question 14

family

Answer 14

A group of closely related genera

Question 15

Genus

Answer 15

A group of closely related species

Question 16

analogous

Answer 16

Trait that is found in different species but is not a result of a common ancestor

Question 17

synapormophies

Answer 17

A sharied derived character trait in two or more taxa

Question 18

outgroup

Answer 18

A group of organisms that has an older common ancestor than the common ancestor of the rest of the taxa

Question 19

Parsimony

Answer 19

choosing the simpler evolutionary explination

Question 20

homology

Answer 20

a shared trait as a result of common ancestor

Question 21

homoplasy

Answer 21

a shared trait asa result of independent evolution

Question 22

Trace fossil

Answer 22

A trace of a trail left by an animal as it moves or burrows into sediments

Question 23

molecular fossils

Answer 23

sterol, bacterial lipid, or some pigment molecule that is relativley resistant to decomposition that document organisms that rarely form conventional fossils

Question 24

Geological timescale

Answer 24

the series of time divisions that mark earths long history

Question 25

radiometric dating

Answer 25

Dating acient materials using the decay of radioisotopes as a yard stick

Question 26

Half-life

Answer 26

the time it takes for half of atoms in a given sample of a substance to decay

Question 27

Mass extinction

Answer 27

A catastrophic drop in the recorded diversity

Question 28

Cambrian explosion

Answer 28

A phase of rapid animal diversification that took place 541 mya. most major phyla of animals appeared during this time

Question 29

Fossil

Answer 29

physical evidence from an organism that lived in the past

Question 30

Habitat bias

Answer 30

Fossils tend to be found more in beaches and swamps (high sedimentation)

Question 31

Tissue bias

Answer 31

Fossils of hard parts are more likely to be found

Question 32

temporal bias

Answer 32

more recent fossils are more likely to be found

Question 33

Abundance bias

Answer 33

the more time and numbers a species had the more likely they would leave fossils behind