Evolution

Question 1

what is macroevolution?

Answer 1

the study of change over time at the level of species or higher

Question 2

what is micro evolution?

Answer 2

the study of change over time in populations

-change in allele frequency in a population over generations

Question 3

what were darwins 3 key observations about life?

Answer 3

1. Organisms are suited for life in their environments
2. Many shared characteristics among living organisms
3. Rich diversity of life

Question 4

what were darwins 2 ideas in the origins of species?

Answer 4

1. descent with modification

2. natural selection

Question 5

what is descent with modification?

Answer 5

Darwin proposed that unity of life due to descent of all organisms from a common ancestor in the distant past
-ancestral species were different from present-day species
-Descendants of ancestral organism lived in various
habitats and over millions of years accumulated
diverse adaptations to fit those specific environment

Question 6

what is natural selection?

Answer 6

• Process in which individuals with certain traits leave more offspring than individuals with other traits
• mechanism of evolution
• Genetic variation in the population over time

-Proposed mechanism by which adaptations emerge
in a population
-over time leads to adaptation

Question 7

through which interactions does natural selection occur? when does the impact of these interactions become noticeable?

Answer 7

-through interactions between individual organisms and their environment
-Impact of natural selection apparent in changes in a
population over time

Question 8

do individual organisms adapt to their environment and evolve?

Answer 8

-no individual organisms do not
-Populations adapt to their environment, Populations
evolve over time

Question 9

what does natural selection change the frequency of?

Answer 9

-changes the frequency of heritable traits in a population
-An organism’s combination of traits affects its
survival and reproductive success

Question 10

what determines if a phenotype is favorable? are they favorable for all individual organisms?

Answer 10

environmental factors

-not necessarily. favorable to individuals of same population, but in another population or time potentially not.

Question 11

what is evolution?

Answer 11

gradual changes in the inherited characteristics of organisms, which are passed from one generation to the next

Question 12

what are 4 evidences for evolution?

Answer 12

1. Direct observation
2. Homology
3. Biogeography
4. Fossil record

Question 13

what is homology? what are the two types?

Answer 13

similarities between organisms resulting from common ancestry
1. anatomical homology –> closely related species
share similar features
-eg. forelimbs of all mammals show same arrangement of bones although appendages have very different functions –> Represent variations on a structure that was present in their common ancestor
2. molecular homology –> similarity among organisms
at molecular level

Question 14

what are 3 examples of molecular homology?

Answer 14

1. All organisms use DNA and RNA
2. Genetic code essential the same for all organisms
3. Organisms have common genes

Question 15

what is biogeography? what does this explain about islands?

Answer 15

closely related species tend to be found in the same geographical area
-Explains why islands with similar environments in
different parts of the world are populated by species
that are not closely related - species resemble those
of nearest mainland

Question 16

how does the fossil record provide evidence for evolution?

Answer 16

-shows past organisms differed from present-day organisms
-Shows evolutionary change occurred over time in
many groups of organisms