ch 22: evolution by natural selection

Question 1

what 2 components make up scientific theories?

Answer 1

pattern and process

Question 2

pattern

Answer 2

observations about natural world

Question 3

process

Answer 3

mechanism that produces the pattern

Question 4

revolutionary

Answer 4

theory of evolution by natural selection

Question 5

what did Plato claim?

Answer 5

every organism was an example of perfect essence, created by God
- typological thinking

Question 6

what did Aristotle believe?

Answer 6

great chain of being
- species were organized into a sequence based on increasing size and complexity

Question 7

what did Lamarck believe?

Answer 7

formal theory of evolution
- simple organisms originate at base of chain by spontaneous generation
- organisms evolve by moving up the chain over time

Question 8

inheritance of acquired characters - lamarck

Answer 8

as individuals develop, their phenotype changes in response to environmental challenges and phenotypic changes are passed to offspring

Question 9

what are Darwin’s beliefs?

Answer 9

species change over time and divergent species share a common ancestor
- natural selection and population thinking

Question 10

natural selection

Answer 10

reproduction and survival is determined by characteristics of an organism in relation to the environment

Question 11

what is natural selection based on?

Answer 11

variation among individuals in populations

Question 12

what do populations consist of?

Answer 12

individuals of the same species living in the same area at the same time

Question 13

how did darwin describe evolution?

Answer 13

descent with modification
- change over time produced modern, modified species from ancestral species

Question 14

how were fossils initially organized?

Answer 14

according to relative ages

Question 15

relative dates

Answer 15

determined by comparison among the sedimentary rock layers

Question 16

absolute dates

Answer 16

determined by tree rings, radiometric dating, and paleomagnetic dating

Question 17

how is extinction evidence for darwin’s beliefs?

Answer 17

species are dynamic and all species living on earth have changed over time

Question 18

transitional features

Answer 18

traits in fossil species that are intermediate between ancestral and derived species
- provide evidence for change over time

Question 19

law of succession

Answer 19

early scientists observed that fossil species are similar to living species in the same geographic areas

Question 20

vestigial trait

Answer 20

a reduced or incompletely developed structure in an organism that has no or reduced function
- similar to functioning organs or structures in closely related species

Question 21

homology

Answer 21

similarity due to descent from common ancestor

Question 22

what 3 levels is homology studied at?

Answer 22

1. genetic
2. development
3. structural

Question 23

genetic homolgy

Answer 23

similarity in DNA nucleotide sequences, RNA nucleotide sequences, or amino acid sequences

Question 24

genetic code

Answer 24

all organisms use the same rules for transferring information coded in DNA into proteins

Question 25

developmental homology

Answer 25

similarity in developmental structures or processes

Question 26

structural homology

Answer 26

similarity in adult morphology - most vertebrates have a common structural plan in limb bones

Question 27

speciation

Answer 27

process that results in one species splitting into two or more descendant species

Question 28

internal consistency

Answer 28

observation that data from independent sources agree in supporting predictions made by a theory

Question 29

artificial selection in pigeon breeding

Answer 29

darwin crossbred pigeons and observed how characteristics were passed on to offspring

Question 30

criteria for natural selection

Answer 30

evolution by natural selection occurs when heritable variation leads to differential reproductive success

Question 31

fitness

Answer 31

ability of an individual to produce surviving, fertile offspring relative to that ability in other individuals in population

Question 32

adaptation

Answer 32

heritable trait that increases an individual's fitness in particular environment relative to individuals lacking that trait

Question 33

selection

Answer 33

differential reproduction as a result of heritable variation