Chapter 18

Question 1

the change in organisms throughout earth’s history

Today’s life is different from and descended from earlier life

“Descent with modification”

Answer 1

Evolution

Question 2

Fixed ideal species

Scala Naturae (ladder of nature)

Answer 2

Aristotle

Question 3

Creation and young earth

Answer 3

Judeo-Christian bible

Question 4

Orderly, nested classification system

Binomial naming (ex: Homo sapiens; genus and species name. Genus is always capitalized and species is not; italicize or underline both)

Answer 4

Linnaeus

Question 5

Fossils are a record of change over time caused by catastrophic events; emphasized the layers as pieces of history (called strata)

Catastrophism

Studied rock strata that mark relative ages and concluded that species changed because of local extinction

Answer 5

Georges Curvier

Question 6

Slow, continuous processes –> geological features

Also called gradualism

Answer 6

James Hutton

Question 7

Father of geology

Uniformitarianism: Geological process in the past occur in the same way as today

Earth is extremely old!

Answer 7

Charles Lyell

Question 8

Physician and natural philosopher

“Natural Philosophy” on evolution

Wrote ideas that “forms minute” slowly acquired complexity over time

Answer 8

Erasmus Darwin

Question 9

Linked evolution to adaptation

Extinct species have been replaced by descendants with new features (adaptations)

First to propose a mechanism for evolution: “use and disuse”; (use it or lose it)

Ex: you’re smart because your parents studied hard

Thought you could inherit acquired characteristics

Ex: I tan in the sun and my child has darker skin

Answer 9

Lamarck

Question 10

Charles Darwin’s two theories

Answer 10

Descent with modification: all present life is related through “descent with modification” from a common ancestor in the past

Natural selection: is the mechanism for evolution and is not random

Question 11

Part 2 of Darwin’s theory

Answer 11

Farmers can enhance small heritable variations by artificial selection or breeding

Question 12

3 observations about the environment that support the concept of natural selection

Answer 12

1. All organisms produce more offspring than is needed
2. Most populations remain fairly stable in size
3. Resources for life are limited

Question 13

evidence in support of Darwin’s theory

Answer 13

direct observation, anti-biotic resistance, the fossil record, homology

Question 14

structures derived from a common ancestor (but may be modified for different functions)– common ancestor, different function (sometimes)

Answer 14

homologous structures

Question 15

examples of homology

Answer 15

vestigial structures, developmental, cellular & molecular

Question 16

remnants of ancestral or homologous structures, structures with no present adaptive function

Answer 16

vestigial structures

Question 17

things that are the same in embryos

Answer 17

developmental homologies

Question 18

similarity of cell structures, proteins and DNA, corresponds to relatedness

Answer 18

cellular and molecular homologies

Question 19

unrelated species have similar adaptations (analogous structures) under similar environmental conditions

Answer 19

convergence

Question 20

Explains both the diversity and unity of life

Accounts for much of form and function

Can predict outcome of environmental change

Answer 20

the theory of evolution by natural selection

Question 21

smallest set of organisms that look alike

Answer 21

morphological species

Question 22

a set of organisms adapted to a specific set of resources (utilize different organic food sources)

Answer 22

ecological species

Question 23

smallest distinct set of organisms that share a common ancestor

Answer 23

phylogenetic species

Question 24

set of populations whose members potentially interbreed in nature to produce fertile, viable, young and do not successfully with other such groups

Answer 24

biological species

Question 25

two individuals who can breed in nature and produce viable (living) fertile offspring

Answer 25

biological species concept

Question 26

they prevent fertilization so that the fertilized egg doesn’t happen

types: habitat (ecological) isolation, temporal isolation, and behavioral isolation, mechanical isolation, gametic isolation

Answer 26

prezygotic barriers

Question 27

they act after a hybrid zygote is formed

reduced hybrid variability, reduced hybrid fertility

Answer 27

post zygotic barriers

Question 28

_____ increases diversity of life

Answer 28

speciation

Question 29

a change in allele frequency over time. It does not make more species but leads to greater diversity with speciation

Answer 29

microevolution

Question 30

Physical barrier isolates one population

Hybrid zones may exist during allopatric speciation; post-zygotic barriers keep gene pools apart

Isolated population diverges genetically due to natural selection and/or genetic drift(happens when you have a small population)

Founder effect could reduce diversity and increase deleterious alleles

Biological reproductive barriers evolve, creating separate species

Answer 30

allopatric speciation