Biology 122 > Unit 4 (Evolution- History, Mechanisms, Speciation, Origin of Life, Macroevolution)🧡 > Flashcards

Unit 4 (Evolution- History, Mechanisms, Speciation, Origin of Life, Macroevolution)🧡 Flashcards

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1
Q

Define Evolution.

A

Change of allele frequencies over time.

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2
Q

What is the #1 mechanism by which Evolution occurs?

A

Natural Selection

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3
Q

How old is the Earth today?

A

4.6 Billion Years Old

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4
Q

How old are the….
1. Oldest bacterial fossils
2. Oldest multicellular fossils
3. Oldest Vertebrate fossils
4. Dinosaurs

A
  1. 3.6 Billion
  2. 2 Billion
  3. 500 Million
  4. 200-65 Million
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5
Q

How old are the…
1. First campfires
2. First modern Humans
3. First cities

A
  1. 1 Million
  2. 250 Thousand
  3. 10 Thousand
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6
Q

What were two incorrect views of those in the 19th century, regarding evolution?

A
  1. They believed the Earth was about 6000 years old.
  2. The Earth/it’s creatures don’t change or go extinct.
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7
Q

Around the mid 19th century new evidence arose to challenge existing belief. What are the four new bits of evidence?

A
  1. Geological evidence=Earth changes
  2. Fossil evidence of extinct organisms were found consistently in similar layers of rock.
  3. Diversity yet consistency in organisms
  4. Over population is inevitable mathematically
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8
Q

What are the five types of organism fossils we find in the strata? In order from oldest to newest.

A
  1. Prokaryotes (single cells)
  2. Multicellular
  3. Inverters (no spine)
  4. Vertebrates (spine)
  5. Humans
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9
Q

What are two patterns scientists in the 19th century noticed across species?

A
  1. Anatomy
  2. Embryos
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10
Q

What is Comparative Anatomy? What did they find?

A
  1. This is the study of comparing the skeletal features of different organisms.
  2. All vertebrates share skeletal similarities.
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11
Q

What is a Vestigial Structure?

A

An anatomical structure that has since lost it’s function, but remained during the process the evolution.

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12
Q

What are five examples of vestigial structures?

A
  1. Leg/hip bones in whales and snakes
  2. Auditory canals in whales
  3. Airfoil shaped wings in flightless birds
  4. Functionless eyes in cave animals
  5. Molars in vampire bats
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13
Q

What is Comparative Embryology? What patterns have we noticed?

A
  1. The comparing of embryos of different species.
  2. Many embryos show similarities, but many are lost before birth.
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14
Q

List the three examples of embryos with traits that show evolutionary change.

A
  1. Baleen Whales- embryos have teeth
  2. Whales- embryos have hair, leg buds, pinnae
  3. Humans- embryos have tails, gils
    (These traits are lost before birth)
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15
Q

Who is Thomas Malthus and why is he important?

A

Malthus is a 19th century scientist who published a book discussing that overpopulation is inevitable.
Why?- (not enough food for the growing populace)

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16
Q

When did Charles Darwin live?

A

1809-1882

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17
Q

What was the title of the book Darwin published? What year was it published?

A
  1. On the Origin of Species
  2. 1859
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18
Q

What did Darwin propose and discuss in “The Origin of Species?”

A
  1. Gave tons of evidence for Evolution
  2. Proposed “Natural Selection” as the mechanism that causes evolution.
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19
Q

Somebody else proposed the “Natural Selection” theory alongside Charles Darwin? Who was it?

A

A.R Wallace

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20
Q

What is Selective Breeding?

A

Breeding an animal in order to pick for a specific wanted trait. (Done by humans)

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21
Q

What are the four Mechanisms of Evolution?

A
  1. Mutation
  2. Immigration & Emigration
  3. Genetic Drift
  4. Natural Selection
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22
Q

What is Mutation?

A

When the sequence of DNA changes

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23
Q

What is an Allele?

A

A variant of a gene

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24
Q

What is Gene Flow?

A

Movement in genetic material from one population to another.

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25
What is Genetic Drift?
Change in allele frequencies due to chance. (Like a freak fire, leaving only some rats alive) -Also known as the "Bottleneck Effect"
26
Why do smaller populations have a LARGER chance of genetic drift?
In larger populations, if 1/4 is killed, then odds are there is enough genetic variation in the other 3/4 to prevent any drastic genetic drift.
27
What is Natural Selection?
Change in allele frequencies due to a change in their fitness. (Red rats don't live to maturity-they can't pass on their genes)
28
What does it mean by biological "Fitness?"
The ability to produce successful offspring (pass on your genes)
29
Walk yourself through how natural selection works.
-More offspring are born than survive, and offspring vary genetically. -Some variations increase survivability (fitness), and then are passed on to the next generation. -So on.
30
What is Differential Reproductive Success?
The case in which some groups have more surviving offspring than others. (They succeeded in reproducing a positive difference.)
31
Who is Lamark and when did he live?
1. Lamark was a scientist that proposed a theory of evolution before Darwin. 2. (1744-1829)
32
What did Lamark propose? What was his theory called?
1. He argued that organisms gained or lost characteristics during their life, and then passed these characteristics (or lack thereof) to their offspring. 2. "Use or disuse"
33
What is Speciation?
The forming of new species.
34
What is a "Species."
Defined as a population that is reproductively isolated from other groups. They only interbreed within their own group. (owls with owls-no other birds)
35
What the problem with our defintion of "Species?"
It's not good for organisms that reproduce asexually.
36
How are some ways speciation occurs?
1. Allopatric Speciation 2. Sympatric Speciation
37
What is Allopatric Speciation?
Speciation caused by geographic isolation.
38
What is Sympatric Speciation? What organisms do this?
This is when one species turns into two distinct species without geographic isolation. 2. Common in plants, but rare in animals
39
What did Stanley Miller do? When?
1. He proved (and showed) that you can make organic molecules from inorganic molecules if energy is supplied. 2. 1953
40
What was Stanley Miller's process to create life?
1. Gather inorganic molecules (water, methane, ammonia, hydrogen) 2. Add energy (heat/electricity) 3. Tada (amino acids, nucleotides, ATP, lipids)
41
How did DNA form?
Monomers will sometimes spontaneously turn into polymers and polymers of nucleotides=DNA.
42
Give four types of evidence for macroevolution. (General)
1. DNA Evidence 2. Comparative Anatomy 3. Comparative Embryology 4. The Fossil Record
43
Give three types of evidence for evolution, regarding DNA.
1. Universal conservation of the genetic code 2. Conservation of gene and protein sequence ❤️ 3. Shared functionless DNA
44
What does it mean when we say there is "Universal Conservation of the Genetic Code?"
-We all share a similar genetic code -It would be more advantageous for us to all have different codes. Sicknesses wouldn't cross over species.
45
What do we mean when we say there is "Conservation of Gene & Protein Sequences?"
The more similar two species are, the more similar their DNA and protein sequences are as well. (huh? ❤️)
46
What is Shared Functionless DNA?
DNA that has no current function for an organism, yet remains.
47
What are two examples of Shared Functionless DNA?
1. Pseudogene for Vitamin C Synthesis 2. Shared Endogenous Retroviruses
48
What is a Pseudogene?
A mutated gene shared by all members of a species.
49
In what organisms can the pseudogene for vitamin c-synthesis be found?
All primates (monkey, humans, lemurs, etc)
50
What is a Retrovirus?
A virus that inserts their DNA into their host's DNA at a specific location.
51
What is an Endogenous Retrovirus?
These are viruses that infected the DNA of reproductive cells of human ancestors, and are now in the DNA of all humans.
52
How do Endogenous Retroviruses help us dictate genetic closeness between species?
Some genetic mutations are shared by some species-but not others. (We can map them out by similarity and disimilarity.)
53
What are the two of methods of dating fossils?
1. Absolute Dating (specific time period) 2. Relative Dating (before x, but after y)
54
What did Relative Dating look like?
Fossils found in deeper sediments were deemed older than ones found in more surface sediment.
55
What are the three types of Absolute Dating?
1. Tree Ring Data 2. Ice core data 3. Radiometric dating
56
How was the gene for Vitamin C synthesis rendered unable to function?
A mutation occurred in which a single nucleotide was deleted from a codon. [ACG] *mutation* [AG]
57
What is Tree Ring Dating? How far in the past can we observe using this kind of data?
1. The study of the past through the analysis of tree rings. 2. We can see back about 12,000 years.
58
What is Dendrochronology?
Tree Ring Dating
59
What is Ice Core Data? How far in the past can we observe using this kind of data?
1. The study of the past through the analysis of extracted layers of ice. 2. Up to a million years ago.
60
What is an Isotope?
Variations of the same element. -Atoms with the same amount of protons, but a slightly different number of neutrons.
61
What is a radioisotope?
An isotope that is radioactive.
62
Why do radioisotopes "decay?"
Radioisotopes are volatile, and are constantly giving off/getting rid of excess energy.
63
What is Potassium-Argon Dating?
A form of radiometric dating.
64
Potassium 40 1. Notation 2. Volatile or stable 3. Form of matter
1. 40K 2. A radioisotope (volatile) 3. Solid
65
Argon-40 1. Notation 2. Volatile or stable 3. Form of matter
1. 40Ar 2. Stable 3. A gas
66
What does Potassium 40 decay into? How long is it's half life?
1. Argon 40 2. 1.3 billion years (It decays by shedding neutrons-so how does it become another element? Does it shed protons too?❤️)
67
What is a half life? Give an example of how this works.
How long it takes for an isotope to reach half-decay of it's original mass. (beginning=100%) *1.3 billion* (50%) *1.3 billion* (25%) *1.3 billion* (12.5%) (Are all isotopes constantly decaying? Is it just radioisotopes? ❤️)
68
What do we use Potassium-Argon dating to figure out the age of?
Rocks?
69
How do we use Potassium-Argon dating to figure out the age of rocks?
We measure the ratios of Potassium and Argon in rocks. Potassium decays to become Argon. Argon (a gas) becomes trapped in solid rocks.
70
Does lava contain Potassium 40? Argon 40?
1. Yes. There is always a quantity of potassium in lava. 2. No because liquids cannot contain gas.
71
What is the general ratio of K/Ar in old rock vs. new rock?
1. Old rock has a low ratio because most of the Potassium has converted to Argon. (1:30) 2. New rock has mostly potassium as it hasn't begun to convert to argon. (30:1)
72
What kind of rock can we use potassium-argon dating to measure?
Igneous rock (solidified lava)
73
What kind of rocks are fossils found in?
Sedimentary rocks
74
How do we use Potassium-Argon dating on fossils?
Igneous rocks are usually found near sedimentary rocks. So we can get a general vibe of their age. (Is this true?❤️)
75
What do we mean when we say a "High Degree of Confidence?"
This is what we say when multiple scientific methods lead to the same conclusion.
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