Chapter 25/26 Flashcards Preview

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Flashcards in Chapter 25/26 Deck (88):
1

Phylogeny 

an evololutionary tree

2

How is evolutionary history reconstructed?

  1. fossil record
  2. comparison of living species
  3. homologous traits
  4. analogous traits
  5. molecular comparisons
  6. geological time

3

homologous traits

similar because they wer inherited from a common ancestor

4

analogous traits

similar, but evolved independently

5

clade

a grouping that includes a common ancestor and its descendents on a phylogeny tree

forms a nested hierarchy

6

Eras

Paleozoic, Mesozoic, Cenozoic

7

Precambrian Era

life arose sometime in this area - 3.5 bya oldest fossils

 

8

What is the earliest fossil?

prokaryote

9

What were the first cells?

protocells

have not been produced in a lab

they are droplets with membranes that have a different internal chemistry than their environment

clay greatly increases the rate of vesicle self-assembly

10

endosymbiotic theory

explains mitochondria and chloroplasts

eukarote engulfing photosynthetic prokaryote. 

11

Key evidence for endosymbiotic theory

  • inner membranes are similar to plasma membranes of prokaryotes
  • division is binary fission
  • thiese organelles have their own DNA (circular) and transcribe and translate it
  • their ribosomes are more similar to prokaryotic than eukaryotic ribosomes

12

cyanobacteria

photosynthesis adds oxygen to asmosphere

first organism to add oxygen to atmosphere

13

Eukaryotes

have a cytoskeleton 

allows them to change shpae and engulf other cells (get food and digestion)

14

Horizontal gene transfer

sharing of genes from one cell to another

  1. most recent common ancestor of all living things
  2. between mitochondrial ancestor and ancestor of eukaryotes
  3. chlooplast ancestor and ancestor of green algae

happened a few times with different plastids

15

advantages of multicellularity

escape from predation, specialization of cells for increased efficiency

single-celled organisms stick together to form colonies

16

choanoflagellate colony

share common ancestor with animals, but didn't become animals

17

unicellular choanoflagellates have the genes for:

collagen, structural proteins in animals

cell adhesion proteins hold cells together

cell communication proteins

 

18

Burgess Shale Fossils: Ediacaran Fauna (aquatic)

all common animals started here

(animals in the pre-cambrian period)

19

Paleozoic Era

Cambrian Period

Evolutionary innovations

gut with 2 openings (allows specialization, can take in more food)

complex nervious system (cephalization - development of head)

shells and exoskeletons (start to see armor)

fish (500mya), amphibians (450mya), reptiles (250mya)

ended with major extinction (90% of all species disappear

Pangea forms

20

Mesozoic period

"Age of Reptiles"

cone-bearing and flower-bearing plants co-evolved with insects

dinosaurs

homeothermy

vertebrate flight (convergent evolution)

ends with major extinction (50% of all species disappear)

21

Extinction of Mesozoic

meteorite 10 km across under water

iridium common in meteorites, but not on earth

extinction because a layer cloud of debris blocked sunlight and disrupted climate for several months

volcanic acitivity of Deccan Traps in India

spew lava and ash

CO2 warms the global climate

temp dif between poles and equator slow mixing of ocean water

drop in O2 levels in oceans

select for anaerobic bacteria that prodcue H2S

H2S is toxic and destroys ozone shield

22

Cenazoic 

65mya-today

"Age of Mammals"

adaptive radiation

macroevolutionary changes

23

Adaptive radiation occurs when:

many vacant niches

major evolutionary innovation

colonized regions with little competition

24

Macroevolution

a pattern of evolution above the species level

big changes

ex: emergence of terrestrial vertebrates through a series of speciation events, impact of mass extinctions of the diversity of life, and the origin of key adaptatios (like flight in birds)

25

Mechanisms of Macroevolutionary change

mutations that change the sequence and regulation of developmental genes

Hox genes

26

Heterochrony

change the relative growth rate or time of different body parts during development

can cause paedomorphosis

27

paedomorphosis

the sexually mature stage retains juvenile structures of an ancestral species

28

Evolution is not goal oriented

random mutations cause genetic diversity

complex structures have evoved in increments from simpler versions that were of use to the organism (sometimes for the same function and sometimes for different functions)

29

exaptation

first used for a different purpose

ex. feathers

30

Formation of eye

gradual changes can result in complex structureEach stage must provide advantage to organism

31

The Hox Genes

duplicate the gene

use gene that controls spatial organization of body parts

Homeotic (Hox) genes control identity of appendages by regulating other genes

Idea: major changes in body form can be made by mutations in the regulation of developmental genes not their sequences

32

each branch point

represents the divergence of 2 species

33

sister taxa

groups that share an immediate common ancestor

34

outgroup

outlier of a common ancestor. relative. 

used to describe evolutionary relationships

characters shared by the outgroup and ingroup are ancestral characters that predate the divergence of both groups froma common ancestor

35

stromatolites

3.5bya, still around

layered rocks that from when certain prokaryotes bind think layers of sediment together

36

Miller-Urey type experiments

demonstrate abiotic synthesis of organic molecules is possible under various assumptions about the composition of the early earth

37

Nature of first genetic material and why

catalytic reactions of ribozymes formed RNA

RNA molecules with certain base sequences are more stable and replicate with fewer errors than other sequences

38

Sedimentary rocks

formed from sand and mud that settled at the bottom of aquatic habitiats and are the richest source of fossils

39

How does radiometric dating work?

Isotypes of radioactive elecments slowly decay into other isotopes.  The rate is measured in half-lives, which is the amount of time it takes for half of the parent isotope to decay.  The amount of these elements remaining in a fossil can be used to determine how old the fossil is.  

40

When did oxygen begin to accumulate in the atomosphere, what molecule produced it, what process?

2.7-2.3 bya gradually increased, water, photosynthesis

41

Cambrian Explosion

535-525 mya

When many present-day animal phyla suddenly appeared in fossil form

42

What adaptations allowed plants to colonize

adaptations that made it possible to reproduce on land and prevent dehydration

for plants, they have a vascular system for transporting materials internally and a waterproof coating of wax on their leaves to slow loss of water

43

What was the first group of animals to colonize land?

anthropods

44

What causes continental drift, when was the last supercontinent?

The continents are throught to float on the mantle, so when the mantle moves, it causes continental drift.

about 250mya Pangea

45

an evololutionary tree

Phylogeny 

46

  1. fossil record
  2. comparison of living species
  3. homologous traits
  4. analogous traits
  5. molecular comparisons
  6. geological time

How is evolutionary history reconstructed?

47

similar because they wer inherited from a common ancestor

homologous traits

48

similar, but evolved independently

analogous traits

49

a grouping that includes a common ancestor and its descendents on a phylogeny tree

forms a nested hierarchy

clade

50

Paleozoic, Mesozoic, Cenozoic

Eras

51

life arose sometime in this area - 3.5 bya oldest fossils

 

Precambrian Era

52

prokaryote

What is the earliest fossil?

53

protocells

have not been produced in a lab

they are droplets with membranes that have a different internal chemistry than their environment

clay greatly increases the rate of vesicle self-assembly

What were the first cells?

54

explains mitochondria and chloroplasts

eukarote engulfing photosynthetic prokaryote. 

endosymbiotic theory

55

  • inner membranes are similar to plasma membranes of prokaryotes
  • division is binary fission
  • thiese organelles have their own DNA (circular) and transcribe and translate it
  • their ribosomes are more similar to prokaryotic than eukaryotic ribosomes

Key evidence for endosymbiotic theory

56

photosynthesis adds oxygen to asmosphere

first organism to add oxygen to atmosphere

cyanobacteria

57

have a cytoskeleton 

allows them to change shpae and engulf other cells (get food and digestion)

Eukaryotes

58

sharing of genes from one cell to another

  1. most recent common ancestor of all living things
  2. between mitochondrial ancestor and ancestor of eukaryotes
  3. chlooplast ancestor and ancestor of green algae

happened a few times with different plastids

Horizontal gene transfer

59

escape from predation, specialization of cells for increased efficiency

single-celled organisms stick together to form colonies

advantages of multicellularity

60

share common ancestor with animals, but didn't become animals

choanoflagellate colony

61

collagen, structural proteins in animals

cell adhesion proteins hold cells together

cell communication proteins

 

unicellular choanoflagellates have the genes for:

62

all common animals started here

(animals in the pre-cambrian period)

Burgess Shale Fossils: Ediacaran Fauna (aquatic)

63

Evolutionary innovations

gut with 2 openings (allows specialization, can take in more food)

complex nervious system (cephalization - development of head)

shells and exoskeletons (start to see armor)

fish (500mya), amphibians (450mya), reptiles (250mya)

ended with major extinction (90% of all species disappear

Pangea forms

Paleozoic Era

Cambrian Period

64

"Age of Reptiles"

cone-bearing and flower-bearing plants co-evolved with insects

dinosaurs

homeothermy

vertebrate flight (convergent evolution)

ends with major extinction (50% of all species disappear)

Mesozoic period

65

meteorite 10 km across under water

iridium common in meteorites, but not on earth

extinction because a layer cloud of debris blocked sunlight and disrupted climate for several months

volcanic acitivity of Deccan Traps in India

spew lava and ash

CO2 warms the global climate

temp dif between poles and equator slow mixing of ocean water

drop in O2 levels in oceans

select for anaerobic bacteria that prodcue H2S

H2S is toxic and destroys ozone shield

Extinction of Mesozoic

66

65mya-today

"Age of Mammals"

adaptive radiation

macroevolutionary changes

Cenazoic 

67

many vacant niches

major evolutionary innovation

colonized regions with little competition

Adaptive radiation occurs when:

68

a pattern of evolution above the species level

big changes

ex: emergence of terrestrial vertebrates through a series of speciation events, impact of mass extinctions of the diversity of life, and the origin of key adaptatios (like flight in birds)

Macroevolution

69

mutations that change the sequence and regulation of developmental genes

Hox genes

Mechanisms of Macroevolutionary change

70

change the relative growth rate or time of different body parts during development

can cause paedomorphosis

Heterochrony

71

the sexually mature stage retains juvenile structures of an ancestral species

paedomorphosis

72

random mutations cause genetic diversity

complex structures have evoved in increments from simpler versions that were of use to the organism (sometimes for the same function and sometimes for different functions)

Evolution is not goal oriented

73

first used for a different purpose

ex. feathers

exaptation

74

gradual changes can result in complex structureEach stage must provide advantage to organism

Formation of eye

75

duplicate the gene

use gene that controls spatial organization of body parts

Homeotic (Hox) genes control identity of appendages by regulating other genes

Idea: major changes in body form can be made by mutations in the regulation of developmental genes not their sequences

The Hox Genes

76

represents the divergence of 2 species

each branch point

77

groups that share an immediate common ancestor

sister taxa

78

outlier of a common ancestor. relative. 

used to describe evolutionary relationships

characters shared by the outgroup and ingroup are ancestral characters that predate the divergence of both groups froma common ancestor

outgroup

79

3.5bya, still around

layered rocks that from when certain prokaryotes bind think layers of sediment together

stromatolites

80

demonstrate abiotic synthesis of organic molecules is possible under various assumptions about the composition of the early earth

Miller-Urey type experiments

81

catalytic reactions of ribozymes formed RNA

RNA molecules with certain base sequences are more stable and replicate with fewer errors than other sequences

Nature of first genetic material and why

82

formed from sand and mud that settled at the bottom of aquatic habitiats and are the richest source of fossils

Sedimentary rocks

83

Isotypes of radioactive elecments slowly decay into other isotopes.  The rate is measured in half-lives, which is the amount of time it takes for half of the parent isotope to decay.  The amount of these elements remaining in a fossil can be used to determine how old the fossil is.  

How does radiometric dating work?

84

2.7-2.3 bya gradually increased, water, photosynthesis

When did oxygen begin to accumulate in the atomosphere, what molecule produced it, what process?

85

535-525 mya

When many present-day animal phyla suddenly appeared in fossil form

Cambrian Explosion

86

adaptations that made it possible to reproduce on land and prevent dehydration

for plants, they have a vascular system for transporting materials internally and a waterproof coating of wax on their leaves to slow loss of water

What adaptations allowed plants to colonize

87

anthropods

What was the first group of animals to colonize land?

88

The continents are throught to float on the mantle, so when the mantle moves, it causes continental drift.

about 250mya Pangea

What causes continental drift, when was the last supercontinent?