Life’s Diversitythrough Evolution

Science vs. ReligionScience vs. Religion What is science based on? What is science based on? Science is based on OBSERVABLE Science is based on OBSERVABLE

evidence. evidence. What is religion based on?What is religion based on? Religion is based on FAITH. Religion is based on FAITH.

– By definition, faith is something that is By definition, faith is something that is not observable. not observable.

Since they are 2 different “fields,” they Since they are 2 different “fields,” they are not competing with each otherare not competing with each other

Religious Scientists?Religious Scientists? ““My religion consists of a humble My religion consists of a humble

admiration of the illimitable superior admiration of the illimitable superior spirit who reveals himself in the spirit who reveals himself in the slight details we are able to perceive slight details we are able to perceive with our frail and feeble mind.” with our frail and feeble mind.” – Albert Einstein (1879 - 1955)Albert Einstein (1879 - 1955)

““Science without religion is lame, Science without religion is lame, religion without science is blind.”religion without science is blind.”– Albert Einstein (1879 - 1955), "Science, Albert Einstein (1879 - 1955), "Science,

Philosophy and Religion: a Symposium", Philosophy and Religion: a Symposium", 19411941

Religious Scientists?Religious Scientists? ““Not only does God play dice, but... he Not only does God play dice, but... he

sometimes throws them where they cannot sometimes throws them where they cannot be seen.”be seen.”– Stephen HawkingStephen Hawking

““In my view, there is no conflict in being a In my view, there is no conflict in being a rigorous scientist and a person who believes rigorous scientist and a person who believes in a God who takes a personal interest in in a God who takes a personal interest in each one of us. Science’s domain is to each one of us. Science’s domain is to explore nature. God’s domain is in the explore nature. God’s domain is in the spiritual world, a realm not possible to spiritual world, a realm not possible to explore with the tools and language of explore with the tools and language of science. It must be examined with the science. It must be examined with the heart, mind and soul.”heart, mind and soul.”– Francis Collins, Director of Human Genome Francis Collins, Director of Human Genome

ProjectProject

Evolution is a TheoryEvolution is a Theory Theory Defined: “scientific principle to Theory Defined: “scientific principle to

explain phenomena: a set of facts, explain phenomena: a set of facts, propositions, or principles analyzed in propositions, or principles analyzed in their relation to one another and their relation to one another and used, especially in science, to explain used, especially in science, to explain phenomena”phenomena”– MSN Encarta, http://encarta.msn.com/dictionary_/theory.htmlMSN Encarta, http://encarta.msn.com/dictionary_/theory.html

Evolution is as much a theory as…Evolution is as much a theory as…– Cell theory: biology– Atomic theory: chemistry– Plate tectonic theory: geology

A Final QuoteA Final Quote

““Be Be opinionated, opinionated, just not just not ignorant.”ignorant.”

EvolutionEvolution

The theory that organisms on Earth have changed over time is known as evolution.

Charles Darwin (1809-1882) is the man who contributed more to our understanding of evolution than any other individual.

Charles Darwin Charles Darwin English naturalist (1809-1882)English naturalist (1809-1882) 1831, Darwin took a job as a 1831, Darwin took a job as a

naturalist on the HMS naturalist on the HMS BeagleBeagle– Went on a 5-year scientific Went on a 5-year scientific

journey around the worldjourney around the world He collected many biological and He collected many biological and

fossil specimensfossil specimens– Combined with his previous and Combined with his previous and

subsequent observationssubsequent observations Published Published On the Origin of Species On the Origin of Species

by Natural Selectionby Natural Selection in 1859 in 1859– These ideas are a basic unifying These ideas are a basic unifying

theme of biology todaytheme of biology today– Without evolution, biology Without evolution, biology

doesn’t make as much sensedoesn’t make as much sense

He realized that he had never seen many of these organisms and the diversity of life on Earth was enormous!

Darwin questioned “Where did all of these different life forms come from?”

EX: Darwin collected 68 species of beetles from Brazil in just a few hours while on shore.

Darwin also discovered many fossils of organisms that no longer existed today. This lead to other questions,

“Where did all these organisms go? And why did they disappear?”

FitnessFitness Darwin observed that many plants and

animals had parts and displayed behaviors that helped them survive.

Traits and behaviors that will help organisms survive and reproduce in their environment give those organisms greater fitness (ability to survive and reproduce).

Those organisms that are most fit will survive and reproduce more often than those organisms who are “less” fit.

Became known as “survival of the fittest.”– Darwin did not use this phrase, it came about

later & may cause misconceptions…

FitnessFitness Darwin argued that increased

fitness arises from adaptations.

Certain adaptations allow organisms to become better suited to their environment, and thus better able to survive and reproduce.

Adaptations can be physical or behavioral

Does “struggle for existence” mean only the biggest, strongest animals survive?  

What types of characteristics increases an organisms chance

of surviving?

Summary of Darwin’s IdeaSummary of Darwin’s Idea

There is variation between individuals.

Summary of Darwin’s IdeaSummary of Darwin’s Idea

Organisms tend to have more offspring than can possibly survive, so there is competition among the offspring for a limited amount of resources

Summary of Darwin’s IdeaSummary of Darwin’s Idea

Organisms compete for limited Organisms compete for limited resourcesresources

There is a struggle for existenceThere is a struggle for existence

Summary of Darwin’s IdeaSummary of Darwin’s Idea

Those organisms that are best suited for their environment (most fit) will survive and pass on their genes.

Darwin’s Theory of Darwin’s Theory of EvolutionEvolution

Darwin developed evolution by natural selection

Compared the process of natural selection in nature vs. artificial selection used by people. He used this comparison to develop a hypothesis to explain how evolution occurs.

Using artificial selection a breeder can produce plants and animals that look very different from their ancestors. Artificial selection uses the variation nature provides.

How does horse racing relate to selective breeding?

Darwin’s Origin of SpeciesDarwin’s Origin of Species He filled notebooks with

ideas about species diversity & the process of evolution.

His beliefs challenged the fundamental ideas of that time (species don’t change).

Darwin was very reluctant to publish his book due to his fear of what the public would think.

Are their any scientific topics today that are controversial?

Origin of SpeciesOrigin of Species

1858, a naturalist name Alfred Wallace sent him a letter describing evolution. He had been working in Malaysia and come to the same conclusions Darwin did.

Darwin had been working on his theory and the evidence to support it for 20 years. Darwin published the Origin of Species in 1859, 23 years after his trip.

Why do you think Darwin waited to publish his book?

Origin of SpeciesOrigin of Species

His book did two things:1. Proposed a mechanism for evolution (natural selection) 2. Evidence showing it had been taking place for millions of years and continues to take place

Descent with ModificationDescent with Modification

Over long periods of time, natural selection will start to produce organisms with different structures or organisms that occupy different niches or habitats. Because of this, species today look different from their ancestors.  

Geological EvolutionGeological Evolution– James Hutton (1788) proposed that rain, James Hutton (1788) proposed that rain,

wind, temperature, and natural disasters wind, temperature, and natural disasters shaped the valleys, mountains, and rocks shaped the valleys, mountains, and rocks over extremely long periods of timeover extremely long periods of time

– Charles Lyell (1830) contributed to this Charles Lyell (1830) contributed to this by adding that current observations of by adding that current observations of volcanic eruptions and other natural volcanic eruptions and other natural disasters shows that Hutton was correct disasters shows that Hutton was correct in assuming the Earth was older than in assuming the Earth was older than originally predictedoriginally predicted

Acceptance of Geological Acceptance of Geological Evolution Evolution

Important to Darwin because it Important to Darwin because it established an OLD Earthestablished an OLD Earth

Darwin’s theory of evolution required Darwin’s theory of evolution required lots of timelots of time

Another important influence: Thomas Another important influence: Thomas MalthusMalthus– Observed that humans were being born Observed that humans were being born

at a faster rate than they were dyingat a faster rate than they were dying– War, famine, and disease control War, famine, and disease control

populationspopulations– These observations provided enough These observations provided enough

curiosity for Darwin to delve deep into his curiosity for Darwin to delve deep into his theory of Natural Selectiontheory of Natural Selection

humans evolve

First placental mammals

Flowering plants dominant

First birds1st dinosaurs

First reptiles

First seed plantsFirst amphibians

First vertebrates

First invertebrates

Life evolves

prokaryoteseukaryotes

Dating TechniquesDating Techniques Geologic Record Geologic Record

– Hypothetical library of all the known geological Hypothetical library of all the known geological processes on Earthprocesses on Earth

– Determined through inference and dating methodsDetermined through inference and dating methods Relative Dating (hee hee) Relative Dating (hee hee)

– Sediments are constantly being laid down.Sediments are constantly being laid down.– Over time, many layers formOver time, many layers form– If a fossil is in a layer below a different fossil, it is If a fossil is in a layer below a different fossil, it is

older than that fossilolder than that fossil

Radiometric DatingRadiometric Dating Radiometric DatingRadiometric Dating

– Radioactive isotopes decay and form new Radioactive isotopes decay and form new isotopes - the rate this happens is called isotopes - the rate this happens is called the isotope’s half lifethe isotope’s half life

– Ex: Potassium-40 decays to argon-40 and Ex: Potassium-40 decays to argon-40 and has a half life of 1.3 billion yearshas a half life of 1.3 billion years Half a sample will decay to argon-40 in Half a sample will decay to argon-40 in

1.3 billion years1.3 billion years So if there are equal amounts of So if there are equal amounts of

potassium-40 and argon-40 in an area, potassium-40 and argon-40 in an area, the sample has been in place 1.3 billion the sample has been in place 1.3 billion yearsyears

– Carbon 14 has a half life of only 70,000 Carbon 14 has a half life of only 70,000 years for more recent sample datingyears for more recent sample dating

Review Review

1.1. How does the geologic record help How does the geologic record help us?us?

2.2. What use is relative dating?What use is relative dating?

3.3. What is radiometric dating?What is radiometric dating?

4.4. Why are different isotopes used in Why are different isotopes used in radiometric dating?radiometric dating?

Evidence for EvolutionEvidence for Evolution Fossil RecordFossil Record

– A hypothetical “library” A hypothetical “library” of all the fossils of all the fossils collected around the collected around the worldworld

Fossils show changes Fossils show changes throughout timethroughout time– 99 percent of all 99 percent of all

animals are now animals are now extinctextinct

– Fossil record shows Fossil record shows ancestors with similar ancestors with similar characteristics characteristics

EmbryologEmbryologyy

Study of embryos and the Study of embryos and the relationships that exist relationships that exist between different speciesbetween different species

Evidence for Evolution: Evidence for Evolution: EmbryologyEmbryology

Many species share features in the Many species share features in the young embryos young embryos – Ex: Mammals, reptiles, birds and fish all Ex: Mammals, reptiles, birds and fish all

have a tail and pharyngeal pouches have a tail and pharyngeal pouches (develop into different respiratory (develop into different respiratory systems)systems)

Evidence For Evolution: Evidence For Evolution: AnatomyAnatomy

Homologous Structures are structural Homologous Structures are structural features with a common evolutionary originfeatures with a common evolutionary origin– Ex: whale forelimb, crocodile forelimb, bird wing, Ex: whale forelimb, crocodile forelimb, bird wing,

human forelimb all look the samehuman forelimb all look the same– Can you think of other examples?Can you think of other examples?

Analogous Structures are body parts or Analogous Structures are body parts or organisms that do not have a common organisms that do not have a common evolutionary origin but are similar in functionevolutionary origin but are similar in function– Bird, bat and butterfly wingsBird, bat and butterfly wings– Show how organisms adapt to different ways of Show how organisms adapt to different ways of

life and different conditions life and different conditions

Homologous Structures

Structure and function between species is the same

Analogous Structures

Functions are the same between species; structures are different

http://evolution.berkeley.edu/evolibrary/article/similarity_hs_01

Evidence for EvolutionEvidence for Evolution

Vestigial Structures Vestigial Structures are body structures are body structures that no longer serve that no longer serve their original purpose, their original purpose, but was probably but was probably useful to an ancestoruseful to an ancestor– Ex: human appendix, Ex: human appendix,

pelvic bone in baleen pelvic bone in baleen whale, “tail” in whale, “tail” in humans, some humans, some human’s ability to human’s ability to wiggle their earswiggle their ears

Vestigial Structures

Evidence shows the organ was once used, but not any longer

Evidence for EvolutionEvidence for Evolution BiochemistryBiochemistry Nearly all organisms Nearly all organisms

share DNA, ATP, and share DNA, ATP, and many enzymes many enzymes among their among their biochemical biochemical moleculesmolecules

Organisms that share Organisms that share more similar more similar enzymes, DNA enzymes, DNA sequences, etc. are sequences, etc. are more closely relatedmore closely related

Review Review 1.1. How did Darwin come up with his ides for natural How did Darwin come up with his ides for natural

selection?selection?2.2. Some snakes have vestigial legs. Why is this Some snakes have vestigial legs. Why is this

considered evidence for evolution?considered evidence for evolution?3.3. Explain how adaptations such as camouflage Explain how adaptations such as camouflage

help species survive.help species survive.4.4. How do homologous structures provide evidence How do homologous structures provide evidence

for evolution?for evolution?5.5. Why did birds and bats both get wings?Why did birds and bats both get wings?6.6. A parasite that lives in red blood cells causes the A parasite that lives in red blood cells causes the

disease called malaria. In recent years, new disease called malaria. In recent years, new strains of the parasite have appeared that are strains of the parasite have appeared that are resistant to the drugs used to treat the disease. resistant to the drugs used to treat the disease. Explain how this could be an example of natural Explain how this could be an example of natural selection occurring. selection occurring.