do now 1. grab weekly 2. grab chapter 12 packet. ch. 12 history of life on earth

DO NOW1. Grab Weekly

2. Grab Chapter 12 Packet

DO NOW1. Grab Weekly

2. Grab Chapter 12 Packet

Ch. 12 History of Life on Earth

Ch. 12 History of Life on Earth

Age of Earth

1. 4.5 billion years ago Earth was a fiery ball of rock

2. Surface of Earth cooled

3. Water vapor in air condensed to form ocean water where life first evolved

How did Life Begin?How did Life Begin?

Measuring the Age of Earth


Scientist have measured the age of the rocks found on Earth using radiometric dating

The age of the rock is measured based on how much it has broken down throughout the years called radioactive decay

Scientist have measured the age of the rocks found on Earth using radiometric dating

The age of the rock is measured based on how much it has broken down throughout the years called radioactive decay




Radioactive Decay of a rock’s content of certain “isotopes” is measured in Half-Lives

Half Life Time it takes for one half of a

certain amount of radioisotope to decay

By measuring this, scientists can calculate how many half lives have passed since a rock was formed

Radioactive Decay of a rock’s content of certain “isotopes” is measured in Half-Lives

Half Life Time it takes for one half of a

certain amount of radioisotope to decay

By measuring this, scientists can calculate how many half lives have passed since a rock was formed

The Theories – How Life BeganThe Theories – How Life Began

1. Formation of Life’s Chemicals

1. Formation of Life’s Chemicals

Nonliving matter was energized by sun and volcanic heat

Caused chemical reaction to produce simple organic molecules

Organics became more complex

First cells developed

Nonliving matter was energized by sun and volcanic heat

Caused chemical reaction to produce simple organic molecules

Organics became more complex

First cells developed


Primordial Soup Model


Hypothesized that Earth’s oceans were once filled with organic molecules (“soup”)

But, there was no oxygen in the air: only nitrogen, hydrogen, water, ammonia, methane

Hypothesized that Earth’s oceans were once filled with organic molecules (“soup”)

But, there was no oxygen in the air: only nitrogen, hydrogen, water, ammonia, methane




Solar radiation, volcanic eruptions, lightning excited electrons in gases

Electrons reacted with Hydrogen in the air to form organic molecules

This hypothesis was actually tested and SUPPORTED!

Solar radiation, volcanic eruptions, lightning excited electrons in gases

Electrons reacted with Hydrogen in the air to form organic molecules

This hypothesis was actually tested and SUPPORTED!

Results – found a complex collection of organic molecules! Compounds included life’s building blocks – amino acids, fatty acids – Hypothesis Supported!

The Theories – How Life Began The Theories – How Life Began

Bubble Model

Bubble Model

Scientists Louis Lerman hypothesized that the key processes that formed the chemicals needed for life took place within bubbles on the oceans surface

The bubbles contained the gases needed to make organic molecules

Chemical reactions took place inside the bubbles and UV radiation made this process occur quickly

Lerman suggested this theory occurred much more quickly than the Primordial Soup Model

Scientists Louis Lerman hypothesized that the key processes that formed the chemicals needed for life took place within bubbles on the oceans surface

The bubbles contained the gases needed to make organic molecules

Chemical reactions took place inside the bubbles and UV radiation made this process occur quickly

Lerman suggested this theory occurred much more quickly than the Primordial Soup Model

Whiteboard – Quick QuestionsWhiteboard – Quick Questions

According to scientists how old is the Earth?

After three half-lives of a radioisotope have passed, how much of the original isotope is undecayed?

(1)1/8 (2) ¾ (3) ½ (4) 7/8

What is “Primordial Soup”?

According to scientists how old is the Earth?

After three half-lives of a radioisotope have passed, how much of the original isotope is undecayed?

(1)1/8 (2) ¾ (3) ½ (4) 7/8

What is “Primordial Soup”?

When did the 1st Organisms Form? When did the 1st Organisms Form?

Evolution of Pro-karyotes


The best evidence we have to study early life are fossils

Fossil- preserved remains (bone, tooth, shell) or imprint of an organism from long ago

The best evidence we have to study early life are fossils

Fossil- preserved remains (bone, tooth, shell) or imprint of an organism from long ago




Oldest fossils - photosynthetic prokaryotes (cyanobacteria) 2.5 billion years old Released oxygen into oceans Oxygen eventually escaped

into air as more and more was produced

Oldest fossils - photosynthetic prokaryotes (cyanobacteria) 2.5 billion years old Released oxygen into oceans Oxygen eventually escaped

into air as more and more was produced

Quick Check - ProkaryotesQuick Check - Prokaryotes



Hold up 1 finger if prokaryotes do have a nucleus

Hold up 2 fingers if they do not

Hold up 1 finger if they are unicellular

Hold up 2 fingers if they are multicellular

Hold up 1 finger if prokaryotes do have a nucleus

Hold up 2 fingers if they do not

Hold up 1 finger if they are unicellular

Hold up 2 fingers if they are multicellular

Two Groups of ProkaryotesTwo Groups of Prokaryotes



Eubacteria Cell walls contain peptidoglycan Cause disease and decay Ex: E.Coli

Archaebacteria Cell walls lack peptidoglycan Unique lipid cell membranes The 1st eukaryotic cells evolved

from archaebacteria

Eubacteria Cell walls contain peptidoglycan Cause disease and decay Ex: E.Coli

Archaebacteria Cell walls lack peptidoglycan Unique lipid cell membranes The 1st eukaryotic cells evolved

from archaebacteria

The Evolution of EukaryotesThe Evolution of Eukaryotes

Evolution of Eu-karyotes


About 1.5 million years ago the first eukaryotes appeared

With your shoulder partner try to come up with 3 characteristics of Eukaryotes

Eukaryotes Larger More Complex Internal Membranes DNA in a nucleus Mitochondria Chloroplasts

About 1.5 million years ago the first eukaryotes appeared

With your shoulder partner try to come up with 3 characteristics of Eukaryotes

Eukaryotes Larger More Complex Internal Membranes DNA in a nucleus Mitochondria Chloroplasts

The KingdomsThe Kingdoms



Biologist group all living things into six kingdoms.

The first two kingdoms are Eubacteria and Archaebacteria

TRY THIS Name the other four kingdoms Circle the kingdom you believe came

first before all the rest

Protists – Fungi – Plants - Animals

Biologist group all living things into six kingdoms.

The first two kingdoms are Eubacteria and Archaebacteria

TRY THIS Name the other four kingdoms Circle the kingdom you believe came

first before all the rest

Protists – Fungi – Plants - Animals

The 1st EukaryotesThe 1st Eukaryotes

The first Eukaryotic Kingdom were Protists

Includes both multi and unicellular organisms

Single celled organisms STILL carry out all of activities for life’s processes (ex: metabolism, homeostasis)

Multicellular protists include Algae

The first Eukaryotic Kingdom were Protists

Includes both multi and unicellular organisms

Single celled organisms STILL carry out all of activities for life’s processes (ex: metabolism, homeostasis)

Multicellular protists include Algae

ExtinctionExtinction

Mass Extinctions

Mass Extinctions

Extinction- Death of all members of a species

Mass Extinction- Episode during which large numbers of species become extinct

The fossil records show large percentages of the Earth’s organisms were becoming extinct

A total of 5 have occurred

Extinction- Death of all members of a species

Mass Extinction- Episode during which large numbers of species become extinct

The fossil records show large percentages of the Earth’s organisms were becoming extinct

A total of 5 have occurred


Mass Extinctions

Mass Extinctions

Most devastating- end of Permian period 245 million years ago 96% of all species became

extinct Cause may have been

worldwide geological and weather changes

Most devastating- end of Permian period 245 million years ago 96% of all species became

extinct Cause may have been

worldwide geological and weather changes


Mass Extinctions

Mass Extinctions

Fifth mass extinction 2/3 of all land species

(including dinosaurs) become extinct

Fifth mass extinction 2/3 of all land species

(including dinosaurs) become extinct


Mass Extinctions

Mass Extinctions

A sixth mass extinction event? May be currently occurring due

to destruction of tropical rain forests by human activity

Can you name the most recent extinction or a species?

A sixth mass extinction event? May be currently occurring due

to destruction of tropical rain forests by human activity

Can you name the most recent extinction or a species?

The Ozone LayerThe Ozone Layer

Ozone Layer

Ozone Layer

Life began in the oceans, why did life suddenly form on land?

UV radiation from the sun is harmful

As cyanobacteria began supplying the air with oxygen, chemical reactions in the atmosphere created the ozone

The Ozone layer blocked the UV radiation and made the Earth’s land a safe place to live

Life began in the oceans, why did life suddenly form on land?

UV radiation from the sun is harmful

As cyanobacteria began supplying the air with oxygen, chemical reactions in the atmosphere created the ozone

The Ozone layer blocked the UV radiation and made the Earth’s land a safe place to live

Whiteboard – Quick QuestionsWhiteboard – Quick Questions

Name the kingdom that includes single and multicellular organisms

Yes or No would today’s organisms exist if the mass extinctions did not occur? Think – Why or why not

How did cyanobacteria contribute to the beginning of more complex life on Earth?

Name the kingdom that includes single and multicellular organisms

Yes or No would today’s organisms exist if the mass extinctions did not occur? Think – Why or why not

How did cyanobacteria contribute to the beginning of more complex life on Earth?

Do NowDo Now

Grab a textbook

Turn in Chapter 11 Take home Exam

p. 8 Wednesday DoNow

**Don’t forget – Weekly Due Friday

Grab a textbook

Turn in Chapter 11 Take home Exam

p. 8 Wednesday DoNow

**Don’t forget – Weekly Due Friday

Section 3 – Gallery WalkSection 3 – Gallery Walk

Each group will be assigned a section from Pages 265 – 268

Make a poster of your section in 15 minutes

Make sure you can answer your questions

We will walk around to each groups poster and have 5 minutes to review and discuss each





Section 3 – Gallery WalkSection 3 – Gallery Walk Each group will be assigned

a section from Pages 265 – 268

Sections: Plants & Fungi on Land – p.265 Arthropods – p. 266 Fish – p.267 Amphibians – p.267 Reptiles – p.268 Mammals & Birds – p.268


Sections: Plants & Fungi on Land – p.265 Arthropods – p. 266 Fish – p.267 Amphibians – p.267 Reptiles – p.268 Mammals & Birds – p.268

Section 3 – Gallery WalkSection 3 – Gallery Walk

Each group will be assigned a section




Each group will be assigned a section





Plants and Fungi on Land


Plants evolved from photo. bacteria Use sunlight to generate

nutrients Cannot harvest materials from

bare rock

Plants evolved from photo. bacteria Use sunlight to generate

nutrients Cannot harvest materials from

bare rock




Fungi Can harvest materials from

bare rock Cannot use sunlight to

generate nutrients

Fungi Can harvest materials from

bare rock Cannot use sunlight to

generate nutrients




Together, they form a mutualistic relationship (both benefit) Mycorrhizae- fungus provides

minerals to plant, and plant provides nutrients to fungi

Together, they form a mutualistic relationship (both benefit) Mycorrhizae- fungus provides

minerals to plant, and plant provides nutrients to fungi


Arthropods

Arthropods

First animals to successfully invade land (first most likely scorpion)

Hard, outer skeleton Segmented body Paired, jointed limbs Lobsters, crabs, insects,

spiders

First animals to successfully invade land (first most likely scorpion)

Hard, outer skeleton Segmented body Paired, jointed limbs Lobsters, crabs, insects,

spiders


Arthropods

Arthropods

Insects Most plentiful, diverse group on

Earth First to have wings and fly Efficient at searching for food,

mates and nesting sites

Insects Most plentiful, diverse group on

Earth First to have wings and fly Efficient at searching for food,

mates and nesting sites


Vertebrates (animals with a backbone)


A. Fishes First vertebrates- small jawless

fishes Jawed fish evolved- allowed

predation Most successful of living

vertebrates Developed into land dwellers

A. Fishes First vertebrates- small jawless

fishes Jawed fish evolved- allowed

predation Most successful of living

vertebrates Developed into land dwellers




B. Amphibians First land vertebrates (to come out

of sea) Smooth skinned, four legged Frogs, toads, salamanders Developed lungs for absorbing

oxygen from air Limbs derived from bones in fish

fins Strong, flexible internal skeleton for

walking Lay eggs in moist areas

B. Amphibians First land vertebrates (to come out

of sea) Smooth skinned, four legged Frogs, toads, salamanders Developed lungs for absorbing

oxygen from air Limbs derived from bones in fish

fins Strong, flexible internal skeleton for

walking Lay eggs in moist areas




C. Reptiles Evolved from amphibians Snakes, lizards, turtles,

crocodiles Watertight skin locks moisture

in while living on land Can lay eggs on dry land

C. Reptiles Evolved from amphibians Snakes, lizards, turtles,

crocodiles Watertight skin locks moisture

in while living on land Can lay eggs on dry land




D. Mammals and Birds Evolved from reptiles 5th mass extinction: only

dinosaurs that were ancestors to birds, small reptiles and small mammals survived

D. Mammals and Birds Evolved from reptiles 5th mass extinction: only

dinosaurs that were ancestors to birds, small reptiles and small mammals survived


Continental Drift

Continental Drift

Movement of land masses over Earth’s surface through geologic time Explains why there are

Marsupials in both Australia and South America although they are extremely far apart

Movement of land masses over Earth’s surface through geologic time Explains why there are

Marsupials in both Australia and South America although they are extremely far apart

Assessment ThreeAssessment Three

Summarize how ozone was important in enabling organisms to live on land

Name the first multicellular organisms that colonized land

Identify the first kinds of animals to live on land Describe the first kinds of vertebrates that inhabited

land Defend the argument that invasion of land could not

have happened until well after the evolution of cyanobacteria

Mycorrhizae are mutualistic relationships between the roots of plants and what other type of organisms?

Summarize how ozone was important in enabling organisms to live on land

Name the first multicellular organisms that colonized land

Identify the first kinds of animals to live on land Describe the first kinds of vertebrates that inhabited

land Defend the argument that invasion of land could not

have happened until well after the evolution of cyanobacteria

Mycorrhizae are mutualistic relationships between the roots of plants and what other type of organisms?

do now 1. grab weekly 2. grab chapter 12 packet. ch. 12 history of life on earth

Documents

early life

life began1

history of life

age of earththe theories

age of earthscientist

organic molecules soupbut

methanethe theories

radiometric datingthe