Topic 1

Question 1

How old is the earth

Answer 1

~4.6 billion years old

Question 2

Original state of the earth (oxygen)

Answer 2

Little to no atmospheric oxygen. In a reduced state

Question 3

Urey-Miller experiment

Answer 3

Simulated early earth conditions and tested chemical origin of life. 2% of carbon was in amino acids, 13 of 22 used in living cells

Question 4

Where can we still find original earth conditions?

Answer 4

In deep oceans there are still some reducing environments

Question 5

First prokaryotes

Answer 5

Oldest known specimens 3.2-3.4 billion years old. Many found in stromatolites

Question 6

Stromatolites

Answer 6

Cyanobacteria form a biofilm that traps layers of sediment. Layers build up into rocks. Appear in fossils 2.7 billion years ago and decline in abundance 500 million years ago

Question 7

Archaean-Proterozoic Era

Answer 7

4 billion - 510 million years ago

Question 8

Cyanobacteria

Answer 8

Obtain energy through photosynthesis, which produces gaseous oxygen. Converted reducing atmosphere to oxidizing (“rusted” the earth). Stimulated biodiversity, led to extinction of oxygen-intolerant organisms

Question 9

Great oxygenation event

Answer 9

Free oxygen accumulates in the atmosphere ~2.5 billion years ago with a big increase ~850 million years ago. Evidence includes banded iron formations (abundant 2.5-1.8 billion years ago then declined) and formation of hydrated and oxidized minerals

Question 10

Why the gap before an oxygenated atmosphere?

Answer 10

Possibly a long period of anoxygenic photosynthesis. Free O2 reacted with ocean chemistry, not immediately released into atmosphere.

Question 11

Cambrian oxygen levels

Answer 11

15-30%

Question 12

Carboniferous oxygen levels

Answer 12

Up to 35%

Question 13

First eukaryotes

Answer 13

Originated from endosymbiosis (archaea + bacteria) ~1.5 billion years ago

Question 14

Paleozoic era

Answer 14

Cambrian explosion, invasion of land, appearance of gymnosperms, major groups of tetrapods

Question 15

Cambrian explosion

Answer 15

~530 million years ago. Rapid appearance of many groups of organisms. Preceded by small shall parts. Appearance of heads, mouths, eyes, legs, etc. Evolution of grazing and reduced algal mats opened new niches

Question 16

Mass extinction

Answer 16

Rate of extinction greatly exceeds rate of speciation. >75% of known species go extinct in a short interval. Clear niches and provide ecological opportunities

Question 17

T/F: evolution is the theory for the origin of life

Answer 17

False. Evolution describes how life has changes since it originated

Question 18

T/F: evolution gives rise to traits that species need for survival

Answer 18

False. Selection can only act on existing variation within a population

Question 19

T/F: Disease genes are retained for evolutionary processes

Answer 19

True. Disadvantageous genes can be maintained by mutation, gene flow, or by being late onset

Question 20

T/F: humans are still evolving by natural selection

Answer 20

True. Continuous adaption to environmental conditions and selection of mating partners

Question 21

T/F: evolution represents a gradual improvement of a species

Answer 21

False. Adaption to one particular set of traits often occurs at the cost of other traits

Question 22

T/F: evolution is slow and gradual

Answer 22

Both. Usually very slow but can be punctuated by rapid bursts or short reproductive lifespans

Question 23

How many known species are alive today?

Answer 23

~2.2 million extant species have been described , ~20% of estimated number

Question 24

For every extant species, how many have gone extinct since the beginning of life?

Answer 24

~100. ~1 billion total species

Question 25

Biological diversity represents…

Answer 25

Reflects an interaction between the forms that preceded them and an ongoing process of change

Question 26

BIOL 213 definition of evolution

Answer 26

Change in allele frequencies in a population over time

Question 27

How do we study evolution?

Answer 27

Genetics (inheritance), population and qualitative genetics (how do allele frequencies change), paleobiology (effects of large scale evolutionary changes), genetics and morphology (developmental patterns)

Question 28

Erasmus Darwin

Answer 28

Wrote about evolution in 1794 (first?)

Question 29

Patrick Matthew

Answer 29

Wrote about evolution in 1831

Question 30

Robert Chambers

Answer 30

Wrote about evolution in 1844

Question 31

Cuvier’s idea

Answer 31

Some species survive while others go extinct. Evidenced by fossils from extinct species

Question 32

Lyell’s idea

Answer 32

The earth must be much older than believed and undergoing change. Landforms form gradually from geological processes

Question 33

Lamarck’s idea

Answer 33

Species themselves must be capable of changing. Proposed “transmutation”, a mechanism of inheritance of acquired traits which was dismissed

Question 34

Malthus’ idea

Answer 34

There must be a pressure to force adaption, for example competition for resources. Fittest individuals survive

Question 35

How long did Darwin wait to publish?

Answer 35

20 years

Question 36

Did Darwin come up with the idea of change due to selection?

Answer 36

No. Artificial selection was well understood from domestication of crops, livestock, dogs, etc. Darwin though if humans can select for desired traits why can’t it occur naturally?

Question 37

Alfred Russell Wallace

Answer 37

Came up with natural selection independently of Darwin but later. Spurred Darwin to publish his own work

Question 38

Darwin’s major conclusions

Answer 38

1. Individuals within a species vary 2. Some variation is inherited 3. More offspring are produced than can survive and reproduce 4. Survival and reproduction is not random but related to phenotypic variation

Question 39

Adaptive radiation

Answer 39

A process in which many organisms diversify rapidly from an ancestral species into many new forms

Question 40

Can natural selection occur without heritability?

Answer 40

Yes but evolution by natural selection cannot

Question 41

Evolution by natural selection is inevitable if:

Answer 41

There is variation in a trait, variation is heritable, and some variants survive and reproduce more than others

Question 42

Doe the environment effect natural selection?

Answer 42

Yes, some environmental features can generate natural selection on a trait