Evidence of Change Evolution

“Evolve” Means to Change Over Time The belief that life on Earth has changed over time is quite old To be considered science, this belief requires a great deal of evidence Evolution

The belief that life on Earth has changed over time is quite old

To be considered science, this belief requires a great deal of evidence

The Development of Evolutionary Theory Naturalists have always wondered at the diversity of living things……… Great varieties in shape, size, and ecological role Estimated 3 million to 20 million different living species Much of the natural world’s biodiversity has vanished through extinction 99% of all species that ever lived are now extinct Permian-Triassic Mass Extinction What Killed the Dinosaurs? Evolution

Naturalists have always wondered at the diversity of living things………

Great varieties in shape, size, and ecological role

Estimated 3 million to 20 million different living species

Much of the natural world’s biodiversity has vanished through extinction

99% of all species that ever lived are now extinct

Permian-Triassic Mass Extinction

What Killed the Dinosaurs?

Development of Evolutionary Theory What could cause such great diversity, and why have so many species died out? Charles Darwin offered an explanation based on careful observations Who was Charles Darwin? Evolution

What could cause such great diversity, and why have so many species died out?

Charles Darwin offered an explanation based on careful observations

Who was Charles Darwin?

Development of Evolutionary Theory Darwin Concluded: Physical traits and behaviors enable organisms to survive and reproduce (called Fitness ) Fitness results from adaptations Darwin reasoned that adaptations result from natural selection and result in evolution Evolution Evolution is the process by which living things change and diversify over time

Darwin Concluded:

Physical traits and behaviors enable organisms to survive and reproduce (called Fitness )

Fitness results from adaptations

Darwin reasoned that adaptations result from natural selection and result in evolution

Development of Evolutionary Theory These ideas were widely challenged until a tremendous amount of evidence was gathered to support evolution! Now…The Theory of Evolution is the Cornerstone of Biology Explore the Evolution Revolution Evolution

These ideas were widely challenged until a tremendous amount of evidence was gathered to support evolution!

Now…The Theory of Evolution is the Cornerstone of Biology

Explore the Evolution Revolution

Evolution Evidence to Support Evolution

The Origin of Life Geology The Fossil Record Comparative Embryology Comparative Biochemistry Comparative Anatomy Isn’t Evolution Just a Theory? Scientists from many disciplines including biology, chemistry, physics, geology, and paleontology have contributed to the case for evolution! Evidence to Support Evolution

The Origin of Life

Geology

The Fossil Record

Comparative Embryology

Comparative Biochemistry

Comparative Anatomy

Isn’t Evolution Just a Theory?

The Origin of Life Origin of the Universe Big Bang ( animation ) Early Earth Evolution Starts Up: Chemical Evolution Heterotroph Hypothesis: Molecules of life arose from inorganic building blocks Evidence to Support Evolution

Origin of the Universe

Big Bang ( animation )

Early Earth

Evolution Starts Up: Chemical Evolution

Heterotroph Hypothesis: Molecules of life arose from inorganic building blocks

The Miller-Urey Experiment Studied Molecules Present at Time of Early Earth Methane, Ammonia, Carbon Dioxide, Water Vapor Mixed Molecules in Reaction Chamber Sparked with Electricity to Simulate Lightning Exposed Mixture to UV Radiation to Simulate Cosmic Rays Produced Basic Amino Acids and Organic Molecules Evidence to Support Evolution

Studied Molecules Present at Time of Early Earth

Methane, Ammonia, Carbon Dioxide, Water Vapor

Mixed Molecules in Reaction Chamber

Sparked with Electricity to Simulate Lightning

Exposed Mixture to UV Radiation to Simulate Cosmic Rays

Produced Basic Amino Acids and Organic Molecules

Miller-Urey Apparatus Evidence to Support Evolution

Biological Evolution RNA as a information molecule and catalyst Endosymbiotic Theory Mitochondria and chloroplasts were originally free living prokaryotic cells Both have own DNA and ribosomes Joined together to cooperate

RNA as a information molecule and catalyst

Endosymbiotic Theory

Mitochondria and chloroplasts were originally free living prokaryotic cells

Both have own DNA and ribosomes

Joined together to cooperate

Geology The Study of the Earth and Rocks Early Ideas About Earth: People believed Earth was only a few thousand years old People believed that rocks and geological features were shaped by catastrophic events and rarely changed Evidence to Support Evolution

The Study of the Earth and Rocks

Early Ideas About Earth:

People believed Earth was only a few thousand years old

People believed that rocks and geological features were shaped by catastrophic events and rarely changed

Geology In the 18 th and 19 th Century Scientists Studied Geology in Great Detail Over millions of years 1 original continent Pangea drifted apart to make our modern continents Continental drift is gradual “gradualism” Evidence to Support Evolution

In the 18 th and 19 th Century Scientists Studied Geology in Great Detail

Over millions of years 1 original continent Pangea drifted apart to make our modern continents

Continental drift is gradual “gradualism”

Geology Hutton and Lyell: Earth is Changed by Weather and Natural Processes like Volcanoes and Erosion Takes a Very Long Time!

Hutton and Lyell: Earth is Changed by Weather and Natural Processes like Volcanoes and Erosion

Takes a Very Long Time!

Geology These ideas refute the idea that the Earth is only a few thousand years old Backed up by radiometric dating The Earth is approximately 4.6 Billion Years Old 4,600,000,000 years is a long time! Evidence to Support Evolution

These ideas refute the idea that the Earth is only a few thousand years old

Backed up by radiometric dating

The Earth is approximately 4.6 Billion Years Old

4,600,000,000 years is a long time!

The Fossil Record Fossils are the preserved remains of ancient organisms Provide information about past organisms Shows that many diverse organisms lived at different times in Earth’s History Evidence to Support Evolution

Fossils are the preserved remains of ancient organisms

Provide information about past organisms

Shows that many diverse organisms lived at different times in Earth’s History

The Fossil Record Taphonomy: The Formation of Fossils Fossils form in sedimentary rock Dead organisms covered by sand and silt Sediments are passed into bone by pressure from above (fossils form in sedimentary rock) Video Evidence to Support Evolution

Taphonomy: The Formation of Fossils

Fossils form in sedimentary rock

Dead organisms covered by sand and silt

Sediments are passed into bone by pressure from above (fossils form in sedimentary rock)

Video

Determining the Age of Fossils Relative Dating: Technique used by scientists to determine the age of fossils relative to fossils in other layers of rock Different layers represent different geologic periods Older fossils found in lower layers, newer fossils found in upper layers Cannot determine the actual age of the fossil! Evidence to Support Evolution

Relative Dating: Technique used by scientists to determine the age of fossils relative to fossils in other layers of rock

Different layers represent different geologic periods

Older fossils found in lower layers, newer fossils found in upper layers

Cannot determine the actual age of the fossil!

Determining the Age of Fossils Radioactive Dating: Process by which traces of radioactive elements are analyzed to calculate the actual age of a fossil Many radioactive elements can be used as geologic clocks. Each radioactive element decays at its own nearly constant rate. Once this rate is known, geologists can estimate the length of time over which decay has been occurring by measuring the amount of radioactive parent element and the amount of stable daughter elements Video Evidence to Support Evolution

Radioactive Dating: Process by which traces of radioactive elements are analyzed to calculate the actual age of a fossil

Many radioactive elements can be used as geologic clocks. Each radioactive element decays at its own nearly constant rate. Once this rate is known, geologists can estimate the length of time over which decay has been occurring by measuring the amount of radioactive parent element and the amount of stable daughter elements

Video

Radiometric Dating Evidence to Support Evolution Radioactive Parent Stable Daughter Half life Potassium 40 Argon 40 1.25 billion yrs Rubidium 87 Strontium 87 48.8 billion yrs Thorium 232 Lead 208 14 billion years Uranium 235 Lead 207 704 million years Uranium 238 Lead 206 4.47 billion years Carbon 14 Nitrogen 14 5730 years

The Geologic Time Scale Based on fossil and geologic evidence A record of the Earth’s past Divided into Era, Period, and Epoch Shows that life on Earth followed geologic change on Earth Deep Time Activity Interactive Time Scale Evidence to Support Evolution

Based on fossil and geologic evidence

A record of the Earth’s past

Divided into Era, Period, and Epoch

Shows that life on Earth followed geologic change on Earth

Deep Time Activity

Interactive Time Scale

Comparative Embryology Embryos are organisms at early stages of development Evidence to Support Evolution

Embryos are organisms at early stages of development

Comparative Embryology All vertebrate embryos, including humans, share features Eye spot (Evolution of the Human Eye) Gill pouches Notochord Shows similar genetic ancestry Video Evidence to Support Evolution

All vertebrate embryos, including humans, share features

Eye spot

(Evolution of the Human Eye)

Gill pouches

Notochord

Shows similar genetic ancestry

Video

Comparative Biochemistry All life is based on organic chemistry Carbon based compounds All life uses same molecule as blueprint DNA Similar chemical processes Bacteria, algae, and plants all do photosynthesis Similar organisms have similar genetic code Humans and chimpanzees share nearly identical genes (98.4% identical gene sequences) Video Evidence to Support Evolution

All life is based on organic chemistry

Carbon based compounds

All life uses same molecule as blueprint

DNA

Similar chemical processes

Bacteria, algae, and plants all do photosynthesis

Similar organisms have similar genetic code

Humans and chimpanzees share nearly identical genes (98.4% identical gene sequences) Video

Anatomy and Comparative Anatomy Vestigial Organs Organs inherited but not used by modern organisms Present but greatly reduced in modern organisms Hip bone in python Appendix in human Tail bone (cocyx) in human Evidence to Support Evolution

Vestigial Organs

Organs inherited but not used by modern organisms

Present but greatly reduced in modern organisms

Hip bone in python

Appendix in human

Tail bone (cocyx) in human

Anatomy: Homologous Structures Similar parts of different organisms, often quite dissimilar in purpose, that developed from the same ancestral body parts (Video) Divergent evolution Evidence to Support Evolution

Similar parts of different organisms, often quite dissimilar in purpose, that developed from the same ancestral body parts (Video)

Divergent evolution

Anatomy: Analogous Structures Similar in purpose, but not inherited from a recent common ancestor Environment selected for trait Wings of birds and insects Convergent evolution Evidence to Support Evolution

Similar in purpose, but not inherited from a recent common ancestor

Environment selected for trait

Wings of birds and insects

Convergent evolution

Summary There is overwhelming evidence to support the Theory of Evolution Evidence comes from disciplines as varied as biology, geology, chemistry, physics, astronomy, and paleontology Evolution has produced the great beauty and diversity of life on Earth over the last 4 billion years Evidence to Support Evolution

There is overwhelming evidence to support the Theory of Evolution

Evidence comes from disciplines as varied as biology, geology, chemistry, physics, astronomy, and paleontology

Evolution has produced the great beauty and diversity of life on Earth over the last 4 billion years

Natural Selection and Speciation

Charles Darwin Studied Medicine and Theology Excelled in Geology and Biology In 1831 Darwin joined the H.M.S. Beagle on a trip around the world to make maps He was the ship’s naturalist Darwin’s Diary

Studied Medicine and Theology

Excelled in Geology and Biology

In 1831 Darwin joined the H.M.S. Beagle on a trip around the world to make maps

He was the ship’s naturalist

Darwin’s Diary

The Voyage of the Beagle: Ports of Call Noted that populations of organisms were slightly different from place to place Each group was modified to their specific environment

The Galapagos Archipelago

Land Iguana Marine Iguana The Galapagos Iguanas

The Galapagos Tortoises

The Galapagos Tortoises

The Galapagos Finches

The Galapagos Finches The Origin of Species Interactive Exploration

Evolution Through Natural Selection There is variation in populations caused by genetics (Praying Mantis Camouflage) Many more offspring are produced than can survive. Many die through predation or starvation Some variations are favorable and help organisms compete to survive and reproduce Over time, the organisms with favorable variations become plentiful. The ones without favorable variations become rare or extinct Reluctantly published On the Origin of Species in 1859 Video

There is variation in populations caused by genetics (Praying Mantis Camouflage)

Many more offspring are produced than can survive. Many die through predation or starvation

Some variations are favorable and help organisms compete to survive and reproduce

Over time, the organisms with favorable variations become plentiful. The ones without favorable variations become rare or extinct

Reluctantly published On the Origin of Species in 1859

Video

Speciation Natural Selection modifies populations. Some evolutionary changes are so great that some organisms can no longer interbreed with the original population A new species results Species An interbreeding population of organisms that can produce healthy, fertile offspring

Natural Selection modifies populations. Some evolutionary changes are so great that some organisms can no longer interbreed with the original population

A new species results

Species

An interbreeding population of organisms that can produce healthy, fertile offspring

Reproductive Barriers and Speciation Prezygotic: gametes never meet and fuse Geographic isolation (allopatric speciation) Ecological isolation Behavioral isolation (lacewing songs) Mechanical isolation Seasonal isolation Postzygotic: genetic differences manifest Hybrid inviability Hybrid sterility ( tigons and ligers)

Prezygotic: gametes never meet and fuse

Geographic isolation (allopatric speciation)

Ecological isolation

Behavioral isolation (lacewing songs)

Mechanical isolation

Seasonal isolation

Postzygotic: genetic differences manifest

Hybrid inviability

Hybrid sterility ( tigons and ligers)

Patterns in Evolution Adaptive Radiation Development of numerous new species from a common ancestor in diverse environments Darwin’s Finches (Origin of Species Activity) Gradualism Punctuated Equilibrium

Adaptive Radiation

Development of numerous new species from a common ancestor in diverse environments

Darwin’s Finches (Origin of Species Activity)

Gradualism

Punctuated Equilibrium

Evolution Produces Diversity All living things are classified by characteristics into 5 kingdoms of life Monera: bacteria, unicellular prokaryotes Protista: single celled eukaryotes Fungi: multicellular, eukaryotic, nonmotile, heterotrophs Plantae: multicellular, eukaryotic, autotrophs Animalia: multicellular, eukaryotic, motile, heterotropohs

All living things are classified by characteristics into 5 kingdoms of life

Monera: bacteria, unicellular prokaryotes

Protista: single celled eukaryotes

Fungi: multicellular, eukaryotic, nonmotile, heterotrophs

Plantae: multicellular, eukaryotic, autotrophs

Animalia: multicellular, eukaryotic, motile, heterotropohs

Linnean Taxonomy Example: human classification Kingdom animalia Phylum chordata Class mammalia Order primate Family hominid Genus homo Species sapiens Binomial nomenclature uses genus and species to make the scientific name Homo sapiens Classification activity

Example: human classification

Kingdom animalia

Phylum chordata

Class mammalia

Order primate

Family hominid

Genus homo

Species sapiens

Binomial nomenclature uses genus and species to make the scientific name

Homo sapiens

Classification activity

Human Evolution

Explore Human Evolution View the Becoming Human broadband documentary As you view each segment, visit the related exhibits to further explore this topic Go to the Learning Center and select the “Calculating Cousins” activity Go to the Learning Center and select the “Chromosome Connection” activity Go to the Learning Center and select the “Building Bodies” activity

View the Becoming Human broadband documentary

As you view each segment, visit the related exhibits to further explore this topic

Go to the Learning Center and select the “Calculating Cousins” activity

Go to the Learning Center and select the “Chromosome Connection” activity

Go to the Learning Center and select the “Building Bodies” activity

The Order Primate Characteristics of Primates Strong hands and opposable thumbs Free-moving shoulder joint Forward facing eyes and stereoscopic vision Intelligence/larger brain Social complexity

Characteristics of Primates

Strong hands and opposable thumbs

Free-moving shoulder joint

Forward facing eyes and stereoscopic vision

Intelligence/larger brain

Social complexity

What Characteristics do Humans Have? All of those of primates, plus Upright posture and bipedal Use of tools and technology Advanced intelligence Complex communication and speech

All of those of primates, plus

Upright posture and bipedal

Use of tools and technology

Advanced intelligence

Complex communication and speech

The Steps to Human Evolution Terrestrialization Bipedal (Walking on all two’s) Increased Brain Size Civilization Take a look at the Human family tree

Terrestrialization

Bipedal (Walking on all two’s)

Increased Brain Size

Civilization

Take a look at the Human family tree

The Hominid Family Each year new fossils are found to add to the Hominid family tree Most fossils of early humans are found in Africa and lower Asia Most well understood members include genus Australopithecus (extinct) and genus Homo Solve the Riddle of the Bones

Each year new fossils are found to add to the Hominid family tree

Most fossils of early humans are found in Africa and lower Asia

Most well understood members include genus Australopithecus (extinct) and genus Homo

Solve the Riddle of the Bones

Genus Australopithecus First human ancestor to live on the ground and walk on two legs As evidenced by the Laetoli footprints Ape-like jaw Small brain Short stature Found only in South and East Africa

First human ancestor to live on the ground and walk on two legs

As evidenced by the Laetoli footprints

Ape-like jaw

Small brain

Short stature

Found only in South and East Africa

The Australopithecines A. anamesis 4 MYA A. afarensis 3.2 MYA (Finding “Lucy”) A. africanus 2.5 MYA A. robustus 2 MYA A. boisei 2 MYA

A. anamesis 4 MYA

A. afarensis 3.2 MYA (Finding “Lucy”)

A. africanus 2.5 MYA

A. robustus 2 MYA

A. boisei 2 MYA

Genus Homo More modern hominids that exhibited major evolutionary steps Increased brain size Use of tools Use of fire Use of shelter Religion Language and civilization

More modern hominids that exhibited major evolutionary steps

Increased brain size

Use of tools

Use of fire

Use of shelter

Religion

Language and civilization

Homo habilis “The Tool Man” Approx. 2.5 MYA Brain ½ size of modern human First to make and use stone tools and weapons

Approx. 2.5 MYA

Brain ½ size of modern human

First to make and use stone tools and weapons

Homo erectus “The Upright Man” Direct ancestor of modern humans Widespread in Africa and Asia by 1 MYA Evidence of use of shelter and fire

Direct ancestor of modern humans

Widespread in Africa and Asia by 1 MYA

Evidence of use of shelter and fire

Homo sapiens “The Wise Man” Most likely evolved from H. erectus as early as 400,000 years ago Greatly increased brain size Consisted of 2 groups Neanderthal Cro-Magnon/modern H. sapiens

Most likely evolved from H. erectus as early as 400,000 years ago

Greatly increased brain size

Consisted of 2 groups

Neanderthal

Cro-Magnon/modern H. sapiens

Neanderthals Found in Neander Valley in Germany Fossils found throughout Europe, Middle East, and Asia from 150,000-30,000 years ago Large bodies and brains Evidenced painting, religion, complex social structure “Cave man”

Found in Neander Valley in Germany

Fossils found throughout Europe, Middle East, and Asia from 150,000-30,000 years ago

Large bodies and brains

Evidenced painting, religion, complex social structure

“Cave man”

Cro Magnons and Fully Modern Humans First early modern H. sapiens appear about 130,000 years ago Thinner bones, smaller jaws, higher skull with little or no brow ridge, and larger brains Cave art shows complex religion and culture Lived alongside Neanderthal for several thousand years, but eventually out-competed them

First early modern H. sapiens appear about 130,000 years ago

Thinner bones, smaller jaws, higher skull with little or no brow ridge, and larger brains

Cave art shows complex religion and culture

Lived alongside Neanderthal for several thousand years, but eventually out-competed them