1.8

AIM: Where did life originate from?

AIM: Where did life originate from?

“…sparked by just the right combination of physical events & chemical processes…”

Bacteria Archae-bacteria

AnimaliaFungiProtista Plantae

4500

4000

3500

3000

2500

2000

500

1500

0

1000

Formation of earth

Molten-hot surface ofearth becomes cooler

Oldest definite fossilsof prokaryotes

Appearance of oxygenin atmosphere

Oldest definite fossilsof eukaryotes

First multicellularorganisms

Appearance of animalsand land plants

Colonization of landby animalsPaleozoic

Mesozoic

Cenozoic

Mill

ion

s o

f ye

ars

ago

AR

CH

EA

N PR

EC

AM

BR

IAN

PR

OT

ER

OZ

OIC

Bacteria Archae-bacteria

AnimaliaFungiProtista Plantae

4500

4000

3500

3000

2500

2000

500

1500

0

1000

Formation of earth

Molten-hot surface ofearth becomes cooler

Oldest definite fossilsof prokaryotes

Appearance of oxygenin atmosphere

Oldest definite fossilsof eukaryotes

First multicellularorganisms

Appearance of animalsand land plants

Colonization of landby animalsPaleozoic

Mesozoic

Cenozoic

Mill

ion

s o

f ye

ars

ago

AR

CH

EA

N PR

EC

AM

BR

IAN

PR

OT

ER

OZ

OIC

The evolutionary tree of life can be documented with evidence.The Origin of Life on Earth is another story…

What is Life?

What is Life?§ First we have to define LIFE…

What is Life?§ First we have to define LIFE…

u organized as cells

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuli

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

u develop

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

u develop § change & mature

within lifetime

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

u develop § change & mature

within lifetime

u reproduce

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

u develop § change & mature

within lifetime

u reproduce§ heredity

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

u develop § change & mature

within lifetime

u reproduce§ heredity

wDNA / RNA

What is Life?§ First we have to define LIFE…

u organized as cellsu respond to stimuliu regulate internal processes

§ homeostasis

u use energy to grow§ metabolism

u develop § change & mature

within lifetime

u reproduce§ heredity

wDNA / RNA

§ adaptation & evolution

The Origin of Life is Hypothesis

The Origin of Life is Hypothesis

The Origin of Life is Hypothesis§ Special Creation

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

u Was the original source of organic (carbon) materials comets & meteorites striking early Earth?

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

u Was the original source of organic (carbon) materials comets & meteorites striking early Earth?

u Heavy bombardment 4bya may have delivered organic compound and water to Earth

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

u Was the original source of organic (carbon) materials comets & meteorites striking early Earth?

u Heavy bombardment 4bya may have delivered organic compound and water to Earth

u testable

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

u Was the original source of organic (carbon) materials comets & meteorites striking early Earth?

u Heavy bombardment 4bya may have delivered organic compound and water to Earth

u testable§ Spontaneous Abiotic Origin

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

u Was the original source of organic (carbon) materials comets & meteorites striking early Earth?

u Heavy bombardment 4bya may have delivered organic compound and water to Earth

u testable§ Spontaneous Abiotic Origin

u Did life evolve spontaneously from inorganic molecules?

The Origin of Life is Hypothesis§ Special Creation

u Was life created by a supernatural or divine force?

u not testable§ Extraterrestrial Origin

u Was the original source of organic (carbon) materials comets & meteorites striking early Earth?

u Heavy bombardment 4bya may have delivered organic compound and water to Earth

u testable§ Spontaneous Abiotic Origin

u Did life evolve spontaneously from inorganic molecules?

u testable

Origin of Organic Compounds

Origin of Organic Compounds

Possible locations that would have allowed the synthesis of organic compounds:

Origin of Organic Compounds

Possible locations that would have allowed the synthesis of organic compounds:

§ Hydrothermal vents deep in the ocean release chemicals, creating unusual chemical conditions

Origin of Organic Compounds

Possible locations that would have allowed the synthesis of organic compounds:

§ Hydrothermal vents deep in the ocean release chemicals, creating unusual chemical conditions

§ Extraterrestrial origin: Scientists have shown that organic compounds could have formed in cold interstellar space and then delivered to Earth by meteors or comets

Origin of Organic Compounds

Possible locations that would have allowed the synthesis of organic compounds:

§ Hydrothermal vents deep in the ocean release chemicals, creating unusual chemical conditions

§ Extraterrestrial origin: Scientists have shown that organic compounds could have formed in cold interstellar space and then delivered to Earth by meteors or comets

§ Chemical reactions in the atmosphere and in water, on the surface of the Earth

Spontaneous Origin of Life

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed for

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

2. Assembly of these organic molecules into polymers (ex. polypeptides)

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

2. Assembly of these organic molecules into polymers (ex. polypeptides)

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

2. Assembly of these organic molecules into polymers (ex. polypeptides)

3. Formation of polymers that can self replicate to allow for the inheritance of characteristics

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

2. Assembly of these organic molecules into polymers (ex. polypeptides)

3. Formation of polymers that can self replicate to allow for the inheritance of characteristics

Spontaneous Origin of LifePasteur disproved “spontaneous generation”

Oldest bacterial fossil date back to 1.9 bya

Processes that would have been needed forthe first cells to form include:

1. Chemical reactions to produce simple organic molecules (ex. amino acids) from inorganic

molecules (ex. water, carbon dioxide)

2. Assembly of these organic molecules into polymers (ex. polypeptides)

3. Formation of polymers that can self replicate to allow for the inheritance of characteristics

4. Packaging of these molecules into membranes with an internal chemistry different from the

Conditions on early Earth

Conditions on early Earth

§ Reducing atmosphere

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

What’s missingfrom that

atmosphere?

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

u lots of available H & its electron

What’s missingfrom that

atmosphere?

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

u lots of available H & its electronlow O2 =

organic molecules do not breakdown as quickly

What’s missingfrom that

atmosphere?

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

u lots of available H & its electronu no free oxygen low O2 =

organic molecules do not breakdown as quickly

What’s missingfrom that

atmosphere?

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

u lots of available H & its electronu no free oxygen

§ Energy source

low O2 =

organic molecules do not breakdown as quickly

What’s missingfrom that

atmosphere?

Conditions on early Earth

§ Reducing atmosphereu water vapor (H2O), CO2, N2, NOx, H2, NH3,

CH4, H2S

u lots of available H & its electronu no free oxygen

§ Energy sourceu lightning, UV radiation,

volcanic

low O2 =

organic molecules do not breakdown as quickly

What’s missingfrom that

atmosphere?

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

CH4

NH3

H2

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

§ Abiotic synthesisCH4

NH3

H2

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

§ Abiotic synthesisu 1920

Oparin & Haldane propose reducing atmosphere hypothesis

CH4

NH3

H2

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

§ Abiotic synthesisu 1920

Oparin & Haldane propose reducing atmosphere hypothesis

u 1953Miller & Urey test hypothesis

CH4

NH3

H2

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

§ Abiotic synthesisu 1920

Oparin & Haldane propose reducing atmosphere hypothesis

u 1953Miller & Urey test hypothesis§ formed organic

compounds

CH4

NH3

H2

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

§ Abiotic synthesisu 1920

Oparin & Haldane propose reducing atmosphere hypothesis

u 1953Miller & Urey test hypothesis§ formed organic

compoundswamino acids

CH4

NH3

H2

Water vapor

Condensed liquid with complex, organicmolecules

CondenserMixture of gases("primitiveatmosphere")

Heated water("ocean")

Electrodes discharge sparks

(lightning simulation)

Water

Origin of Organic Molecules

§ Abiotic synthesisu 1920

Oparin & Haldane propose reducing atmosphere hypothesis

u 1953Miller & Urey test hypothesis§ formed organic

compoundswamino acidswadenine

CH4

NH3

H2

Stanley Miller

University of Chicago

produced-amino acids

-hydrocarbons-nitrogen bases-other organics

It’s ALIVE!

Phospholipids

Phospholipids

§ Hydrophobic or hydrophilic?u fatty acid tails = hydrophobicu PO4 = hydrophilic head

u dual “personality”

Phospholipids

§ Hydrophobic or hydrophilic?u fatty acid tails = hydrophobicu PO4 = hydrophilic head

u dual “personality”

interaction with H2O is complex & very important!

Phospholipids

§ Hydrophobic or hydrophilic?u fatty acid tails = hydrophobicu PO4 = hydrophilic head

u dual “personality”

interaction with H2O is complex & very important!

It likes water & also pushes

it away!

Phospholipids in water

Phospholipids in water

§ Hydrophilic heads attracted to H2O

Phospholipids in water

§ Hydrophilic heads attracted to H2O

§ Hydrophobic tails “hide” from H2O

Phospholipids in water

§ Hydrophilic heads attracted to H2O

§ Hydrophobic tails “hide” from H2Ou can self-assemble into “bubbles”

Phospholipids in water

§ Hydrophilic heads attracted to H2O

§ Hydrophobic tails “hide” from H2Ou can self-assemble into “bubbles”

§ can also form bilayer

Phospholipids in water

§ Hydrophilic heads attracted to H2O

§ Hydrophobic tails “hide” from H2Ou can self-assemble into “bubbles”

§ can also form bilayer

bilayer

Phospholipids in water

§ Hydrophilic heads attracted to H2O

§ Hydrophobic tails “hide” from H2Ou can self-assemble into “bubbles”

§ can also form bilayer

§ early evolutionary stage of cell?

bilayer

Origin of Cells (Protobionts)§ Bubbles → separate inside from outside → metabolism & reproduction

Bubbles…Tiny bubbles…

Origin of Cells (Protobionts)§ Bubbles → separate inside from outside → metabolism & reproduction

Origin of GeneticsDawn of natural selection

Origin of Genetics

§ RNA is likely first genetic material

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functional

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

§ self-replicating molecule

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

§ self-replicating molecule

§makes inheritance possible

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

§ self-replicating molecule

§makes inheritance possible

§ natural selection & evolution

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

§ self-replicating molecule

§makes inheritance possible

§ natural selection & evolutionu enzyme functions

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

§ self-replicating molecule

§makes inheritance possible

§ natural selection & evolutionu enzyme functionsu transport molecule

Dawn of natural selection

Origin of Genetics

§ RNA is likely first genetic materialu multi-functionalu codes information

§ self-replicating molecule

§makes inheritance possible

§ natural selection & evolutionu enzyme functionsu transport molecule

§ tRNA & mRNA

Dawn of natural selection

Key Events in Origin of Life

Key Events in Origin of Life

§ Key events in evolutionary history of life on Earth

Key Events in Origin of Life

§ Key events in evolutionary history of life on Earthu life originated

3.5–4.0 bya

Prokaryotes

§ Prokaryotes dominated life on Earth from 3.5–2.0 bya

Prokaryotes

§ Prokaryotes dominated life on Earth from 3.5–2.0 bya

Prokaryotes

§ Prokaryotes dominated life on Earth from 3.5–2.0 bya

3.5 billion year old fossil of bacteria

Prokaryotes

§ Prokaryotes dominated life on Earth from 3.5–2.0 bya

3.5 billion year old fossil of bacteria modern bacteria

chains of one-celledcyanobacteria

StromatolitesFossilized mats of prokaryotes resemble modern microbial colonies

StromatolitesFossilized mats of prokaryotes resemble modern microbial colonies

StromatolitesFossilized mats of prokaryotes resemble modern microbial colonies

StromatolitesFossilized mats of prokaryotes resemble modern microbial colonies

Oxygen atmosphere

Oxygen atmosphere

Oxygen atmosphere

§Oxygen begins to accumulate 2.7 bya

Oxygen atmosphere

§Oxygen begins to accumulate 2.7 byau reducing → oxidizing atmosphere

Oxygen atmosphere

§Oxygen begins to accumulate 2.7 byau reducing → oxidizing atmosphere

§ evidence in banded iron in rocks = rusting

Oxygen atmosphere

§Oxygen begins to accumulate 2.7 byau reducing → oxidizing atmosphere

§ evidence in banded iron in rocks = rusting§makes aerobic respiration possible

Oxygen atmosphere

§Oxygen begins to accumulate 2.7 byau reducing → oxidizing atmosphere

§ evidence in banded iron in rocks = rusting§makes aerobic respiration possible

u photosynthetic

Oxygen atmosphere

§Oxygen begins to accumulate 2.7 byau reducing → oxidizing atmosphere

§ evidence in banded iron in rocks = rusting§makes aerobic respiration possible

u photosynthetic u algae)

First Eukaryotes

DNA

cell wall

plasmamembrane

nuclear envelope

plasma membrane

~2 bya

First Eukaryotes

DNA

cell wall

plasmamembrane

Prokaryoticcell

nuclear envelope

plasma membrane

~2 bya

First Eukaryotes

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

nuclear envelope

plasma membrane

~2 bya

First Eukaryotes

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

nuclear envelope

plasma membrane

~2 bya

First Eukaryotes

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

endoplasmicreticulum (ER)

nuclear envelope

plasma membrane

~2 bya

First Eukaryotes

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

endoplasmicreticulum (ER)

nuclear envelope

nucleus

plasma membrane

~2 bya

First Eukaryotes

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

Eukaryoticcell

endoplasmicreticulum (ER)

nuclear envelope

nucleus

plasma membrane

~2 bya

First Eukaryotes

§ Development of internal membranes

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

Eukaryoticcell

endoplasmicreticulum (ER)

nuclear envelope

nucleus

plasma membrane

~2 bya

First Eukaryotes

§ Development of internal membranesu create internal micro-environments

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

Eukaryoticcell

endoplasmicreticulum (ER)

nuclear envelope

nucleus

plasma membrane

~2 bya

First Eukaryotes

§ Development of internal membranesu create internal micro-environmentsu advantage: specialization = increase efficiency

infolding of theplasma membrane

DNA

cell wall

plasmamembrane

Prokaryoticcell

Prokaryotic ancestor of eukaryotic

cells

Eukaryoticcell

endoplasmicreticulum (ER)

nuclear envelope

nucleus

plasma membrane

~2 bya

Endosymbiosis

internal membrane system

Endosymbiosis

Endosymbiosis

internal membrane system

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotes

internal membrane system

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotes

Ancestral eukaryotic cell

internal membrane system

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of mitochondria

Ancestral eukaryotic cell

internal membrane system

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of mitochondria

Ancestral eukaryotic cell

internal membrane system

aerobic bacterium

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of mitochondriau engulfed aerobic bacteria,

but did not digest them

Ancestral eukaryotic cell

internal membrane system

aerobic bacterium

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of mitochondriau engulfed aerobic bacteria,

but did not digest themu mutually beneficial relationship

Ancestral eukaryotic cell

internal membrane system

aerobic bacterium

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of mitochondriau engulfed aerobic bacteria,

but did not digest themu mutually beneficial relationship

Ancestral eukaryotic cell

internal membrane system

aerobic bacterium mitochondrion

Endosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of mitochondriau engulfed aerobic bacteria,

but did not digest themu mutually beneficial relationship

Ancestral eukaryotic cell

Eukaryotic cellwith mitochondrion

internal membrane system

aerobic bacterium mitochondrion

Endosymbiosis

mitochondrionEndosymbiosis

Endosymbiosis

mitochondrionEndosymbiosis

Endosymbiosis

§ Evolution of eukaryotes

mitochondrionEndosymbiosis

Endosymbiosis

§ Evolution of eukaryotes

Eukaryoticcell with

mitochondrion

mitochondrionEndosymbiosis

Endosymbiosis

§ Evolution of eukaryotesu origin of chloroplasts

Eukaryoticcell with

mitochondrion

mitochondrionEndosymbiosis

photosyntheticbacterium

Endosymbiosis

§ Evolution of eukaryotesu origin of chloroplasts

Eukaryoticcell with

mitochondrion

mitochondrionEndosymbiosis

photosyntheticbacterium

Endosymbiosis

§ Evolution of eukaryotesu origin of chloroplasts u engulfed photosynthetic bacteria,

but did not digest them

Eukaryoticcell with

mitochondrion

mitochondrionEndosymbiosis

photosyntheticbacterium

Endosymbiosis

§ Evolution of eukaryotesu origin of chloroplasts u engulfed photosynthetic bacteria,

but did not digest themu mutually beneficial relationship

Eukaryoticcell with

mitochondrion

mitochondrion

chloroplast

Endosymbiosis

photosyntheticbacterium

Endosymbiosis

§ Evolution of eukaryotesu origin of chloroplasts u engulfed photosynthetic bacteria,

but did not digest themu mutually beneficial relationship

Eukaryoticcell with

mitochondrion

mitochondrion

chloroplast

Eukaryotic cell withchloroplast & mitochondrion

Endosymbiosis

photosyntheticbacterium

Endosymbiosis

§ Evolution of eukaryotesu origin of chloroplasts u engulfed photosynthetic bacteria,

but did not digest themu mutually beneficial relationship

Eukaryoticcell with

mitochondrion

Theory of Endosymbiosis

Theory of Endosymbiosis

Lynn Margulis

§ Evidence

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

§mitochondria & chloroplasts resemble bacterial structure

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

§mitochondria & chloroplasts resemble bacterial structure

u genetic

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

§mitochondria & chloroplasts resemble bacterial structure

u genetic§mitochondria & chloroplasts

have their own circular DNA, like bacteria

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

§mitochondria & chloroplasts resemble bacterial structure

u genetic§mitochondria & chloroplasts

have their own circular DNA, like bacteriau functional

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

§mitochondria & chloroplasts resemble bacterial structure

u genetic§mitochondria & chloroplasts

have their own circular DNA, like bacteriau functional

§mitochondria & chloroplasts move freely within the cell

Theory of Endosymbiosis

Lynn Margulis

§ Evidenceu structural

§mitochondria & chloroplasts resemble bacterial structure

u genetic§mitochondria & chloroplasts

have their own circular DNA, like bacteriau functional

§mitochondria & chloroplasts move freely within the cell

§mitochondria & chloroplasts reproduce independently from the cell

Theory of Endosymbiosis

Lynn Margulis