Ch 22

Question 1

3 key observations about life?

Answer 1

organisms are adapted for life in their biotic & abiotic envrionemnts, many shared characteristics (unity) of life, diversity of life

Question 2

evolution

Answer 2

the process by which species accumulate differences from their ancestors as they adapt to diff environments over time

Question 3

adaptations

Answer 3

inherited characteristics that enhance an organism’s survival & reproduction in specific environments

Question 4

natural selection

Answer 4

proccess in which individuals w/ certain inherited traits tend to survive & reproduce at higher rates b/c of those traits

Question 5

descents w/ modification by natural selection explains

Answer 5

unity of life, diversity of life, way organisms are suited to life in their environments

Question 6

artificial selection

Answer 6

breeding only individuals with desired traits

Question 7

Darwin described 2 observations of nature

Answer 7

1. members of a pop often vary in their inherited traits
2. all species can produce more offspring then the environment can support, & many of these offspring fail to survive & reproduce

Question 8

Important points about evolution through natural selection

Answer 8

1. individuals do not evolve; it’s the pop. that evolves over tme
2. natural selection can only inc or dec heritable traits that are variable in a pop
3. environment varies from place to place & over time; favorable traits vary with environment

Question 9

4 types of data that doc pattern of evolution

Answer 9

direct observation, homology, fossil record, biogeography

Question 10

homology

Answer 10

similarity resulting from common ancestry, another type of evidence for evolution

Question 11

homologous structures

Answer 11

anatomical resemblances that represent variations on a structureal theme present in a common ancestor - have same arrangement but different functions

Question 12

vestigial “left over” structures

Answer 12

remnants of features that served a function in organism’s ancestors

Question 13

evolutionary trees

Answer 13

diagrams that reflect hypotheses about the relationships among groups

Question 14

convergent evolution

Answer 14

independent evolution of similar, or analogous, festures in distantly related groups

Question 15

analogous features share

Answer 15

similar functions, but not common ancestry

Question 16

biogeography

Answer 16

scientific study of the geographic distribution of species and provides support for evolution