Evolution

Question 1

Facts about the theory of evolution by natural selection

Answer 1

1. reproductive rates
2. all organisms are variable

Question 2

Theory of Evolution

Answer 2

The differences among individuals influence how well those individuals survive and reproduce. Traits that increase the probability that their bearers will reproduce successfully are more likely to be passed on to their offspring and to subsequent generations.

Question 3

Evidence in support of the theory of evolution

Answer 3

1. fossil records
2. artificial selection
3. phylogenetic similarities

Question 4

Fossil Record

Answer 4

1. gradualism
2. gaps
3. punctuated equilibrium

Question 5

gradualism

Answer 5

rate of evolution has been constant

Question 6

gaps

Answer 6

gaps in the fossil record; example: cetaceans > remedied by fossil records showing several stages in transition of cetaceans from land to sea and DNA evidence shows that existing non-cetaceans to which cetaceans are most closely related are hippopotami.

Question 7

punctuated equilibrium

Answer 7

new adaptations > exploit new niches > adaptive radiations
example: bats

Question 8

Dating methods

Answer 8

1. radiometric dating (carbon 14)
2. potassium 40 : argon 40

Question 9

Potassium-argon dating

Answer 9

Potassium-40 decays to Argon-40 w/ a half-life of about 1.26x10^9 years. This makes it very useful for dating older fossils sandwiched between layers of volcanic rock. When Argon-40 is trapped in volcanic rock and the rock is hated, the argon gas is driven off but potassium remains. This resets the “clock” for potassium-40 decay to zero. The current ratio of K:Ar in a layer of volcanic rock gives an estimate of when that layer was formed.

Question 10

artificial selection

Answer 10

Examples: dogs bred from wolves, varieties of pigeons, chicken combs (increasing), veggies from wild cabbage (broccoli, brussels sprouts, kale, etc.), resistance of bacteria to antibiotics, etc.

Question 11

Phylogenetic Similarities

Answer 11

1. morphology/anatomy
2. vestigial organs
3. comparative embryology
4. comparative genetics

Question 12

morphology/anatomy

Answer 12

homologous limbs, a common ancestor with the same bones (but different shapes)

Question 13

vestigial organs/structures

Answer 13

a feature of an organism that is a historical remnant of a structure that served a function in the organism’s ancestor
ex: humans’ appendix and tailbone, Panda’s thumb, etc.

Question 14

comparative embryology

Answer 14

early embryos: similar morphologies
late embryos: different morphologies
evolution acted upon the development of a common ancestor to regulate the later stages of development into species-specific forms

Question 15

comparative genetics

Answer 15

genetic code was the same from bacteria to humans > sequences of conserved genes became progressively more different with evolutionary time

Question 16

Differences in coding regions of globin gene?

Answer 16

0.08% among humans
1.1% between humans and chimps
1.5% between humans and gorillas
1.6% between chimps and gorillas
humans and chimps are more closely related than chimps and gorillas

Question 17

Random processes in adaptive evolution

Answer 17

mutation and sexual recombination

Question 18

non-random processes in adaptive evolution

Answer 18

natural selection (most reproductively fit individuals)