11

Wild Ride to EvolutionWild Ride to Evolution

Mark MayoMark Mayo

Cypress CollegeCypress College

Last update 8/27/13

22

AristotleAristotle He lived in 384-322 BCHe lived in 384-322 BC He employed descriptive He employed descriptive

visual examination – visual examination – early classification of early classification of plants and animalsplants and animals

Had problems with Had problems with sponges – looked like sponges – looked like plants, but did not make plants, but did not make food and were not greenfood and were not green

Mushrooms were also Mushrooms were also troublingtroubling

33

Science of Biogeography Science of Biogeography

Scientists of the time cataloged life Scientists of the time cataloged life across the planetacross the planet

As people traveled more we found As people traveled more we found more varied forms of lifemore varied forms of life

We communicated and wrote down We communicated and wrote down findingsfindings

We found more and more diversity We found more and more diversity across the planetacross the planet

44

Science of BiogeographyScience of Biogeography

55

Comparative Anatomists Comparative Anatomists They had a very systematic studyThey had a very systematic study Organisms were grouped by body Organisms were grouped by body

plans – plans – called the science of taxonomycalled the science of taxonomy (classification)(classification)**

Question came up – why are body Question came up – why are body plans so diverse? Why are some plans so diverse? Why are some similar?similar?

Body plans were thoughtBody plans were thoughtto be perfect to be perfect ((religious overtonesreligious overtones))

66

Comparative AnatomistsComparative Anatomists

Can you see the similarities?

77

Comparative Comparative AnatomistsAnatomists

88

Comparative AnatomistsComparative Anatomists

There were problems There were problems with with vestigial organsvestigial organs** (parts that no longer (parts that no longer function normally)function normally)**• tailbonetailbone• appendixappendix• pelvic girdle in snakes pelvic girdle in snakes

99

Geologists enter the picture Geologists enter the picture

They found They found that the earth that the earth had layers of had layers of rock and sand rock and sand even “solid” even “solid” rock rock appearedappearedto be to be constructed constructed of layers of layers

1010

GeologyGeology

Fossils are Fossils are preserved evidence preserved evidence of organismsof organisms

1111

GeologyGeology

Geologists Geologists found similar found similar rock layers rock layers around the around the worldworld

Beneath Beneath these top these top layers fossils layers fossils could be could be found found

1212

GeologyGeology

Fossils Fossils were were found only found only in certain in certain layers over layers over the earththe earth

Digs Digs around the around the world had world had similar similar fossilsfossils

1313

GeologyGeology

As they dug deeper fossils they found As they dug deeper fossils they found certain constantscertain constants• fossils got older as you dug deeper (usually)fossils got older as you dug deeper (usually)• fossils became simpler as you went back (more fossils became simpler as you went back (more

complex now)complex now)• certain fossils disappeared, some appearedcertain fossils disappeared, some appeared• older digs showed more marine organisms, older digs showed more marine organisms,

then completely marine!then completely marine!• at some point there are no more signs of lifeat some point there are no more signs of life• the fossil world had creatures that are now the fossil world had creatures that are now

extinctextinct

1414

GeologyGeology

More on the geologist’s viewsMore on the geologist’s views• Rocks come in a variety of compositionsRocks come in a variety of compositions• A great length of time is needed to wear A great length of time is needed to wear

away soft ones to sand or soil with away soft ones to sand or soil with various agents of erosionvarious agents of erosion

windwind rainrain surfsurf iceice

• Hard rocks take even longer to erodeHard rocks take even longer to erode

1515

GeologyGeology To form sedimentary rock takes time to To form sedimentary rock takes time to

both build up and then erodeboth build up and then erode It is likely that the time periods involved in It is likely that the time periods involved in

evolution are millions of years not evolution are millions of years not thousandsthousands

Catastrophes occur every year: Catastrophes occur every year: earthquakes, volcanoes, great storms, etc.earthquakes, volcanoes, great storms, etc.

Theory of uniformityTheory of uniformity – slow, gradual – slow, gradual change not just dramatic changes caused change not just dramatic changes caused by major geologic events makes sense, by major geologic events makes sense, but both theories used together is but both theories used together is commonly accepted nowcommonly accepted now

1616

GeologyGeology

Scientists were disturbed by obvious problems Scientists were disturbed by obvious problems between geology and the biblical story creationbetween geology and the biblical story creation• 6,000 – 10,000 year old earth6,000 – 10,000 year old earth• The event of all species created at same time in same The event of all species created at same time in same

place was not supported by fossil evidenceplace was not supported by fossil evidence• The thought that there could be NO new organisms since The thought that there could be NO new organisms since

creation could not be supportedcreation could not be supported• We find new species as we move to higher rock strataWe find new species as we move to higher rock strata• The extinction of organisms is regularly observedThe extinction of organisms is regularly observed

1717

Trouble Brews as science thinks Trouble Brews as science thinks about these facts in a religious light about these facts in a religious light

Religious (Biblical) beliefs were Religious (Biblical) beliefs were hard to reconcile with geologyhard to reconcile with geology

Fossils and elaborate rock Fossils and elaborate rock formations took great time periods formations took great time periods while the biblical account is 6 days while the biblical account is 6 days and one day of restand one day of rest

Biblical earth was thought to be Biblical earth was thought to be 6-10,000 years (too short for 6-10,000 years (too short for geologists)geologists)

It appeared as if multiple origin It appeared as if multiple origin sites were indicated by geology – sites were indicated by geology – not one location and one creationnot one location and one creation

Perhaps there was just too much Perhaps there was just too much evidence of evidence of change over timechange over time** (the definition of Evolution)(the definition of Evolution)**

1818

Fathers of Evolution Theory Before Fathers of Evolution Theory Before Darwin – Darwin – a mostly religious groupa mostly religious group

George Cuvier George Cuvier (1769-1832) – (1769-1832) –

The Theory of The Theory of CatastropismCatastropism• He did not believe He did not believe

in evolution in evolution • He was religious He was religious

person, a practicing person, a practicing ProtestantProtestant

1919

George CuvierGeorge Cuvier

He founded He founded vertebrate vertebrate paleontology paleontology (first real (first real practitioner)practitioner)

Vertebrate Vertebrate paleontology is paleontology is the study of the study of fossils with fossils with backbones. backbones.

2020

George CuvierGeorge Cuvier

He based his theories He based his theories on series of abrupt on series of abrupt changes in the earth changes in the earth which are seen in the which are seen in the fossil record caused fossil record caused by catastrophesby catastrophes

A catastrophe can A catastrophe can include: volcanic include: volcanic eruption, hurricane, eruption, hurricane, flood, meteor strikeflood, meteor strike

2121

George CuvierGeorge Cuvier The Theory of CatastropismThe Theory of Catastropism

Artist’s rendition of a meteor strike on earth

2222

George CuvierGeorge Cuvier He believed in a singular creation where He believed in a singular creation where

all life was made all life was made He believed that after a catastrophe the He believed that after a catastrophe the

population changed population changed When major catastrophes killed off many – When major catastrophes killed off many –

survivors repopulated the worldsurvivors repopulated the world We would see evidence in fossils after We would see evidence in fossils after

their numbers increased, they were always their numbers increased, they were always there (we just had not found them yet)there (we just had not found them yet)

With successive catastrophes we see more With successive catastrophes we see more “new” organisms “new” organisms

2323

Jean Baptise Lamarck Jean Baptise Lamarck **

Jesuit (a type of Jesuit (a type of Catholic) seminarian Catholic) seminarian

Theory of acquired Theory of acquired traitstraits**• if you need to have a if you need to have a

changed body part – changed body part – just grow itjust grow it

• offspring would keep offspring would keep the newly changed the newly changed body partbody part

• this theory worked well this theory worked well with creation with creation

2424

Jean Baptise LamarckJean Baptise Lamarck

The force to change was a “drive to The force to change was a “drive to perfection”perfection”

FluidaFluida was the substance housed in was the substance housed in our nerves that moved to the area our nerves that moved to the area where change was needed and where change was needed and caused the body part to changecaused the body part to change

2525

Jean Baptise LamarckJean Baptise Lamarck Classic giraffe neck Classic giraffe neck

explanation according to explanation according to LamarckLamarck• giraffes had short necks at giraffes had short necks at

startstart• as food supply dwindled as food supply dwindled

accessible to short necks accessible to short necks there was a need for a longer there was a need for a longer neck to reach higher on treesneck to reach higher on trees

• fluida caused the neck to fluida caused the neck to lengthenlengthen

• all offspring had longer and all offspring had longer and longer neckslonger necks

• the environment was the the environment was the causative agent of changecausative agent of change

The theory of acquired traits is no longer accepted **

2626

Jean Baptise LamarckJean Baptise Lamarck Darwin explains the giraffeDarwin explains the giraffe

• there is a diversity in giraffe there is a diversity in giraffe necks after millions of years of necks after millions of years of existenceexistence

• the leaves are eaten on the the leaves are eaten on the lower branches of the treeslower branches of the trees

• giraffes with longer necks eat giraffes with longer necks eat and are healthy enough to and are healthy enough to breedbreed

• short giraffes eat less, do not short giraffes eat less, do not have as much sex and die offhave as much sex and die off

• the surviving “taller” giraffe’s the surviving “taller” giraffe’s offspring inherit the trait for offspring inherit the trait for heightheight

• more giraffes are taller over more giraffes are taller over timetime

2727

Jean Baptise LamarckJean Baptise Lamarck

He caused He caused people to start people to start thinking, but thinking, but the theory of the theory of acquired traits acquired traits was a failure was a failure then and now then and now

2828

Charles Lyell Charles Lyell Theory of UniformityTheory of Uniformity 1797-1875 1797-1875 He started his career as a He started his career as a

lawyer – later turned to lawyer – later turned to geology and zoologygeology and zoology

Lyell rebelled against Lyell rebelled against geology based in biblical geology based in biblical timing and catastrophes as timing and catastrophes as the only causes for changethe only causes for change

He thought gradual change He thought gradual change of earth with much more of earth with much more time (billions vs. thousands time (billions vs. thousands of years) seemed more of years) seemed more logicallogical

2929

Charles LyellCharles Lyell

Gradual changes can cause major changes Gradual changes can cause major changes in the earth as shown in these photos of in the earth as shown in these photos of the Grand Canyonthe Grand Canyon

From earth From space

3030

Charles LyellCharles Lyell

His work led to the book – His work led to the book – Principles of GeologyPrinciples of Geology

Darwin read his bookDarwin read his book just before he just before he left for voyage of the Beagleleft for voyage of the Beagle

Another evolutionary scientist named Another evolutionary scientist named Wallace also read his bookWallace also read his book

3131

Thomas Malthus Thomas Malthus

Principle of populationPrinciple of population 1766-1834 1766-1834 ReligiousReligious He thought that He thought that

famine and poverty famine and poverty were divine were divine institutions to keep us institutions to keep us from being lazyfrom being lazy

3232

Thomas MalthusThomas Malthus Humans produce far more offspring than can Humans produce far more offspring than can

survivesurvive The larger the population, the more they would The larger the population, the more they would

reproducereproduce Living space, food supply and other resources Living space, food supply and other resources

could not support populationcould not support population Competition increasesCompetition increases People would starve, get sick and start warsPeople would starve, get sick and start wars He saw that conditions were deteriorating in He saw that conditions were deteriorating in

society society He thought that unless population was controlled He thought that unless population was controlled

that all life would ceasethat all life would cease

3333

Thomas MalthusThomas Malthus Almost anyone has seen overcrowding in Almost anyone has seen overcrowding in

cities, especially in third world citiescities, especially in third world cities

3434

Thomas MalthusThomas Malthus

He had a great influence on both great He had a great influence on both great evolutionists: evolutionists: Darwin and Wallace Darwin and Wallace

ZZ Top

3535

Charles Darwin (1809-1882) – Charles Darwin (1809-1882) – Father of Theory of Evolution Father of Theory of Evolution

3636

Charles DarwinCharles Darwin

His life before His life before BeagleBeagle• naturalist naturalist

at heartat heart• tried medicine – tried medicine –

quitquit• tried clergy, tried clergy,

earned a earned a degree in degree in theologytheology

• He was somewhat He was somewhat religiousreligious

3737

Charles DarwinCharles Darwin He sailed away on a 5 He sailed away on a 5

year voyage of Beagleyear voyage of Beagle**• no formal training as a no formal training as a

naturalist – but hired to naturalist – but hired to be ship’sbe ship’s** naturalist naturalist

• job of voyage was to map job of voyage was to map worldworld

• studied South America, studied South America, Australia, many islandsAustralia, many islands

• found unbelievable found unbelievable diversity in life formsdiversity in life forms

• found life forms never found life forms never before seen and found before seen and found nowhere else (Australia)nowhere else (Australia)

• after his return he after his return he devoted his life to study devoted his life to study of evolutionof evolution

3838

Charles DarwinCharles Darwin Darwin’s enhancement of Malthus, Lyell mixed Darwin’s enhancement of Malthus, Lyell mixed

with Beagle informationwith Beagle information• moved Malthus people only theories to all organismsmoved Malthus people only theories to all organisms• fish, frogs, insects do produce thousands to millions of fish, frogs, insects do produce thousands to millions of

eggseggs• most offspring do not survive (eaten, die because of most offspring do not survive (eaten, die because of

some weakness or competition)some weakness or competition)• the environment keeps population in checkthe environment keeps population in check• Beagle showed Darwin that there was great diversity Beagle showed Darwin that there was great diversity

(EXTREME)(EXTREME)• he decided that diversity exists to allow an advantage in he decided that diversity exists to allow an advantage in

competitioncompetition• this advantage is called this advantage is called adaptationadaptation (biological term) (biological term)• he figured that variety is good and needed to allow for he figured that variety is good and needed to allow for

changing conditions over timechanging conditions over time

3939

Charles DarwinCharles Darwin

Darwin’s finches Darwin’s finches **• 13 species of 13 species of finchesfinches found in Galapagos Islands found in Galapagos Islands• each species varied by their each species varied by their beaks and feetbeaks and feet**

short and strong beakshort and strong beak long and narrow beakslong and narrow beaks sharp beakssharp beaks medium beaksmedium beaks

• each modification allowed the bird species to survive and each modification allowed the bird species to survive and forage for food effectively based on its local environmentforage for food effectively based on its local environment

4040

Charles DarwinCharles Darwin

4141

Charles DarwinCharles Darwin One example of finch evolutionOne example of finch evolution

• a variety of beaks exist at start (long, short, strong, a variety of beaks exist at start (long, short, strong, weak, etc.)weak, etc.)

• if seeds available become mostly hard (the weather if seeds available become mostly hard (the weather changed)changed)

• birds with stronger shorter beaks are the ones best able birds with stronger shorter beaks are the ones best able to eat seedsto eat seeds

• if you eat more, breed more and you stay aliveif you eat more, breed more and you stay alive• if the stronger bill is caused by a gene that can be if the stronger bill is caused by a gene that can be

passed to bird’s offspring, then offspring too have passed to bird’s offspring, then offspring too have stronger beakstronger beak

• over time the environment would SELECT for birds with over time the environment would SELECT for birds with a particular beak structurea particular beak structure

• the most ADAPTIVE version of the bill trait (GENE) would the most ADAPTIVE version of the bill trait (GENE) would become commonbecome common

• the population would change over time = EVOLUTION the population would change over time = EVOLUTION

4242

Charles DarwinCharles Darwin

Natural SelectionNatural Selection• natural selection was and is a Darwinian ideanatural selection was and is a Darwinian idea• it alarmed Darwin who was religious with a it alarmed Darwin who was religious with a

theology degree theology degree • wrote down his ideas in “Origin of the Species”wrote down his ideas in “Origin of the Species”• he was a bit afraid to speak uphe was a bit afraid to speak up• his wife said he would for sure go to hell and so his wife said he would for sure go to hell and so

might she if he published his workmight she if he published his work• he kept it unpublished for 10 years! he kept it unpublished for 10 years!

4343

Charles DarwinCharles Darwin

4444

Alfred Wallace (1823-1913)Alfred Wallace (1823-1913) he traveled like Darwin to Spice he traveled like Darwin to Spice

Islands in IndonesiaIslands in Indonesia he found great diversityhe found great diversity Wallace also read Malthus and Wallace also read Malthus and

LyellLyell he published “On the Law which he published “On the Law which

has regulated the Introduction has regulated the Introduction of New Species” in 1858of New Species” in 1858

later, he published with Darwinlater, he published with Darwin he forced Darwin to publishhe forced Darwin to publish Wallace agreed Darwin had idea Wallace agreed Darwin had idea

firstfirst

4545

Charles DarwinCharles Darwin

Origin of the Species is published in Origin of the Species is published in 18591859• accepted by naturalists and some accepted by naturalists and some

scientistsscientists• rejected by religious and other scientistsrejected by religious and other scientists• after 70 years genetics finally makes after 70 years genetics finally makes

theory much strongertheory much stronger• genetics lets us know how genes code genetics lets us know how genes code

for traits and how they are passed down for traits and how they are passed down

4646

Darwin’s TheoriesDarwin’s Theories any population can evolve (change over time) any population can evolve (change over time)

when individuals differ by one or more heritable when individuals differ by one or more heritable trait (can be passed on to offspring) that are trait (can be passed on to offspring) that are responsible for differences in the ability to survive responsible for differences in the ability to survive and reproduceand reproduce

not just survival of the fittest – must be able to not just survival of the fittest – must be able to produce more offspringproduce more offspring

natural selection natural selection ** – difference in survival rates – difference in survival rates among individuals of a given population that among individuals of a given population that differ from one another in one or more heritable differ from one another in one or more heritable traitstraits**

natural selection results in a modification of traits natural selection results in a modification of traits within a line of descentwithin a line of descent

over time natural selection can result in a new over time natural selection can result in a new speciesspecies

SPECIES SPECIES – group of individuals that can mate and – group of individuals that can mate and produce fertile offspringproduce fertile offspring

4747

Charles DarwinCharles Darwin

4848

Artificial SelectionArtificial Selection** Selective breedingSelective breeding**

• we have been breeding selectively for we have been breeding selectively for all recorded timeall recorded time

• this causes man-made evolution!this causes man-made evolution!• breed ones we like, eat or kill ones breed ones we like, eat or kill ones

we don’t likewe don’t like**• we breed for a variety of reasons:we breed for a variety of reasons:

SizeSize StrengthStrength ColorColor sex (American Indians/Indians from Asia)sex (American Indians/Indians from Asia) early horses were smallearly horses were small early dogs were tree-climbing and early dogs were tree-climbing and

very smallvery small corn was colorful and much smallercorn was colorful and much smaller genetic engineering is new frontier genetic engineering is new frontier