The 7 Characteristics of Life #71. Order/Organization (Life, Energy, Entropy) R2. Regulation R 3. Growth and Development (via DNA) R4. Energy utilization R 5. Responds to stimuli R6. Reproduce (according to a DNA plan) R7. E Evolve / Adapt (changes DNA)

The 7 Characteristics of Life #7E Evolve/Adapt (via changes in DNA)

evolution of dance

End Chapter 1 Begin Chapter 13

Evolution Evolution: A change in the genetic make-up of a

population. (A change in the gene pool) Of the 7 characteristics of life, this one is unique in

that it is a characteristic of populations. Individuals are metabolic, homeostatic, respond, grow

and develop, reproduce, are cellular, etc. but they DO NOT evolve.

Populations evolve, individuals do not !!Evolution is a population phenomenon !!

As is perhaps true for much of what you believe about evolution, if you believe that you can evolve, you must unlearn that and learn what is really going on

A Gene PoolEvolution is a change in the genetic

make-up of a population

A Gene PoolEvolution is a change in the genetic

make-up of a populationA population has a gene pool; an individual has a genome.

EvolutionThe idea of ideas…A word about words…

Evolution: Biology’s Most Important Idea !

Dobzhansky…

Development of ideas in general. Development of the idea of evolution in particular. Why? (study this idea in Billeter’s bio class)

Most important idea in biology… researched, dissected, dissed, poked, kicked applauded, defamed,

tested, screamed at, misinterpreted, debated, more than… Illustrates relation between science and… Illustrates that science is not divorced from the rest of our society but

is rather, science is an integral part of our society. It is the most powerful paradigm in guiding our understanding

of life including human life.

PARADIGMSThere are ideas and there are IDEAS.

The biggies are called paradigms.

ATOMIC THEORY CELL THEORY PLATE TECTONICS BIG BANG E=mc2

2nd LAW OF THERMODYNAMICS ETC.

Evolution Biology’s most famous

book: On the Origin of Species…

Why Darwin? Why England? Why 1859?

We’ll come back to this… but be thinking about:

• WHY THIS GUY?• IN THIS PLACE?• AT THIS TIME?

Evolution Where does this idea come from anyway?

Class Activity 1 (5 minutes): Make a list of many different living things. (easy)

Group Activity 2 (5 minutes): Consider your 21 things and all the other living things and

formulate 4 of the most basic and fundamental questions you can think of to ask about all of Earth’s living things i.e. What do you think are the most fundamental questions of the science of biology? (hard)

e.g. one thing I want to know about life and I think biologists ought to figure out is: how, who, why, what, when, where, what’s up with…

So, what did Aristotle think? 384-322 BC

First to make (write down) a distinction between

NaturalExplanations

and

SupernaturalExplanations

So what did Aristotle ask? 384-322 BC

1. What is the nature of the “soul” or “vital force” of life? What’s responsible for making certain blobs of matter and energy “BE ALIVE”?

So what did Aristotle ask? 384-322 BC

2. Is being alive the same thing for all the life we see around us? Or are there different types of “being alive?” Dolphin, mushroom, sponge, bug…

So what did Aristotle ask? 384-322 BC

3. What’s required to maintain life? i.o.w. What is needed to keep something alive?

So what did Aristotle ask? 384-322 BC

4. Why are there so many kinds of life?(the biodiversity question)

So what did Aristotle ask? 384-322 BC

5. Why are similar organisms similar? How do you account for natural groupings?

So what did Aristotle ask? 384-322 BC

6. Why do like produce like? Why do offspring always resemble their parents?

Like always begets like!

The Age of Enlightenment

Emerge from Dark Ages 476 A.D. - c.1450 A.D. Renaissance approx. 1300s -1500s Age of Enlightenment 16, 1700’s

The Age of Enlightenment

Scientists exhibiting the skepticism and empiricism that characterize modern science.

Questioning established ideas.

Observers of the living world were asking questions too.

The questions of Aristotle are revived. Historically:

Ages of Exploration and Colonial Expansion. New and bewildering specimens flood the

museums of Europe. New and bewildering religions and cultures are

being “discovered.” Industrial Revolution.

• More on this later…

Big Questions of Biology(1700’s version)

1. Why is life so diverse? How do you explain the thousands if not millions of species?

2. What do fossils mean?3. Why are certain groups of organisms similar to

each other?4. Why are others different?5. How, if at all, are extant species related to the

fossils they resemble?6. How, if at all, are similar organisms in different

places related?

Evolution? Many of these questions COULD BE

answered quite easily IF organisms could change (evolve).

And most of them COULD NOT be answered well if organisms couldn’t change.

But most 18th C biologists did not believe that organisms evolved. They believed instead…

Evolution?1. As Aristotle had said about 2000 years

earlier, ladder of life…

2. According to the Genesis account in the Judeo/Christian Old Testament…Divine creation a.k.a Special creation.

Challenges to absolute literalism arise from astronomy and geology before biology.

Copernicus

16C

Galileo

1564-1642

17C

Hutton

1726-1797

18C

Lyell

1797-1875

19C

So how does a theory of evolution arise out of this 18th century thinking?

James Hutton (1726-1797) Theory of UniformitarianismorUniformityorGradualism

Uniformitarianism vs Catastrophism

3 Implications of Gradualism1. Earth is very old.

Bishop Ussher (1654) dates the creation of the world at 4004 BC. Sir James Lightfoot improves that calculation to 9 AM Oct 3, 4004 BC. The 6000 year old Earth idea.

Hutton suggests Earth’s age should be measured in at least millions of years.

Modern estimates from radiometric dating and other lines of research age Earth at 4.5 billion.

Three Implications of Gradualism

2. Slow gradual change of the geologicalworld is “normal.”

Three Implications of Gradualism3. There may be other interpretations of the

Judeo/Christian Bible than an absolute literal interpretation. This one really is an implication; Hutton never wrote it.

So religious interpretation and empirical interpretation are in conflict. And remain so.

What do these geology ideas have to do with biology???

It’s pretty obvious that organisms “match” their environments.

Had they lived at the same time (they didn’t), Darwin may well have asked Hutton:

‘Hey Jim, if your geologic world is changing gradually and continuously, is it not possible, as a matter fact, is it not likely, that the biological world is changing too?

‘Hey Jim, if your geologic world is changing gradually and continuously, is it not possible, as a matter fact,

likely, that the biological world is changing too?

Well, perhaps. But ya gotta have a MECHANISM !!!If ya wanna say somethin’s happenin’ ya gotta explain

HOW !!

Jean Baptiste Pierre Antoine de Monet

Chevalier de Lamarck (1744-1829)

takes a shot at answering “How?”

Evolution Through the Inheritance of Acquired Characteristics

Acquired Characteristics = non-Genetic Characteristics

Jean Baptiste Pierre Antoine de Monet Chevalier de Lamarck

(1744-1829)

Evolution Through the Inheritance of Acquired Characteristics

Jean Baptiste Pierre Antoine de Monet Chevalier de Lamarck

(1744-1829)

Evolution Through the Inheritance of Acquired Characteristics

The real poop on giraffes: Click HERE for a great video on giraffes.

Nope !

Lamarck’s idea does not survive So…we turn to Chuck Darwin

1809-1882

Charles Darwin

1809-1882

Voyage of HMS Beagle 1831-1836

“On the Origin of Species” 1859 JB

Fig. 13-02

1809

Lamarck

publishes

his theory

of evolution.

1830

Lyell publishes

Principles of Geology.

1837

Darwin begins analyzing his

specimens and writing his

notebooks on the origin

of species. 1844

Darwin writes his essay

on the origin of species.1865

Mendel publishes

papers on genetics.

1858

Wallace sends an

account of his

theory to Darwin.

1859

Darwin publishes

The Origin of Species.

1809

Charles Darwin

is born.1831–36

Darwin travels

around the world

on the HMS Beagle.

Green sea turtle in the

Galápagos Islands

1800

1870

Evolution Biology’s most famous

book: On the Origin of Species…

So… we ask again? Why Darwin? Why England? Why 1859?

So, let’s address these questions… What ‘s up with THIS GUY in THIS PLACE at THIS TIME ???

Science is always affected by the larger society in which it operates.

(Heck, almost everything is affected by the larger society in which it operates !!)

Age of Exploration (mid 1400’s - mid 1500’s)

Age of Colonial Expansion (early 1500’s – late 1700’s +)the voyage of the Beagle was part of the Colonial Era

Industrial Revolution (1730’s – early 1900’s)

How do these large scale social/historical events affect Darwin and the development of evolutionary theory?

Science is affected by the larger society in which it operates.

-- the growth of natural history museums -- lavishly illustrated coffee-table books

The Industrial Revolution

The Industrial Reolvution

The Voyage of the H.M.S. Beagle1831-1836

Fig. 17-6c, p.265

Lyell: Principles of Geology

The Voyage of the H.M.S. Beagle

The Voyage of the H.M.S. Beagle

Convergent EvolutionRhea, SA; Emu, Aust; Ostrich, Africa

Fig. 17-3a, p.262

A phylogeny of living and extinct flightless birds based on DNA sequences suggests that although moas and kiwis both live in New Zealand, they are not each other's closest relatives.

Kiwis are more closely related to the emus and cassowaries of Australia and New Guinea.

Convergent Evolution

Fig. 17-3a, p.262

Fig. 17-8a, p.260

Darwin on the Galapagos Islands(divergent evolution and co-evolution)

Darwin on the Galapagos Islands

Darwin on the Galapagos IslandsPrickly Pear Cactus, Opuntia

Darwin on the Galapagos Islands Prickly Pear Cactus on the Galapagos

Darwin on the Galapagos IslandsWhy the tall cactuses with “bark”?

Why the saddle-back tortoise?(co-evolution)

?

Darwin on the Galapagos IslandsGiant Tortoises of the Galapagos

Darwin on the Galapagos Islands“Darwin’s Finches”

(divergent evolution vs convergent evolution vs co-evolution/parallel evolution)

Darwin on the Galapagos Islands “Darwin’s Finches”

There are distinct differences.

Rose-breasted grosbeak, Pheucticus ludovicianus, N.A., & Canada

Geospiza magnirostris, G. fortis, G. parvula, Certhidea olivacea, Galapagos

Peter and Rosemary Grant, Princeton U.

Galapagos Finches

Darwin on the Galapagos Islandsadaptive radiation, radial evolution, divergent evolution

Darwin on the Galapagos IslandsConvergent vs. Divergent Evolution

Darwin, 1859, makes two real clear statements about evolution…

1. It happens !and… 2. It happens by natural selection.

TEXTBOOK: a) descent from common ancestora.k.a “descent with

modification” b) natural selection

PROF: It’s as easy as ABC: A. Variation … withB. Consequences … passed down byC. Heredity

Darwin begins his discussion of Evolution by Natural Selection with a discussion of

“Evolution” by Artificial Selection (=Breeding)

Darwin begins his discussion of Evolution by Natural Selection with a discussion of

“Evolution” by Artificial Selection (Breeding)

Evolution of the domestic dog

Arose c. 40,000 ybp in eastern Asia.

Most modern breeds arose in past 200-300 yrs Europe.

Most were produced by European breeders in the 19th C.

Darwin begins his discussion of Evolution by Natural Selection with a discussion of “Evolution” by Artificial Selection (Breeding)

How do you make a dachshund?

Artificial Selection = Breeding

Corn (Zea mays)and Teosente

Forced selection in Drosophila,the common fruit fly, this was

done by breeding, in the natural world this would be an example of “disruptive selection.”

Artificial Selection vs. Natural Selection

Artificial Selection has two parts:1. Random Genetic Variation which is acted upon by…

2. Artificial Selection

Natural Selection has two parts:1. Random Genetic Variation which is acted upon by…

2. Natural Selection

VARIATION + CONSEQUENCE + HEREDITY

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead

to 3 conclusions. Observations

1. Natural populations reproduce exponentially2. Yet, they stay rather constant in number3. Organisms exhibit natural variation in structure, physiology,

behavior, “traits.”4. Some variations are heritable.

Conclusions1. Competition2. Natural Selection3. Evolution (by natural selection).

Observation 1

Observation 3Conclusion 1

Observation 4Conclusion 2

Observation 2

Conclusion 3

+

+

+

Set it up like this!

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Observation #1Natural populations reproduce exponentially. Natural

populations of organisms have the capacity to produce way more offspring than then the environment could possibly support if ALL the offspring survived.

Blue crab ~ 1 mill codfish ~23 mill ocean sunfish ~ 54 mill

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Observation #1Natural populations reproduce exponentially. Natural

populations of organisms have the capacity to produce many more offspring than then the environment could possibly support if ALL the offspring survived.

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Observation #2Yet, natural populations stay rather constant over time.

Observations #1 & #2 deal with population growthZPG

Rev. Thomas Malthus 1798

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Observations #1 & #2 deal with population growth

Natural populations reproduce exponentially. Natural populations of organisms have the capacity to produce many more offspring than then the environment can support if ALL the offspring survived (so they all don’t survive) !

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Observation #1 & #2Natural populations reproduce exponentially. Natural populations of organisms have the capacity to produce many more offspring than then the environment could possibly support if ALL the offspring survived. So they don’t (all survive) ! Many die before they reproduce.

Observation #1

Observation #2

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Observation #3Natural populations exhibit variation in structure, function,

behavior, etc.

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions. (see p. 267)

Observation #4Some of these variations are HERITABLE. (They can be passed from generation to generation via

reproduction. And some can’t!)

Darwin’s idea is based on 4 observations that lead to 3 conclusions.

Observation #4Some characteristics are heritable and will be passed along to future generations

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Conclusion #1 CompetitionThere will be competition for food, mates, space, refugia,

sunlight, the best parking space, etc.

Darwin’s idea is not very complicated. It is based on 4 (empirical) observations which lead to 3 conclusions.

Conclusion #2: Natural SelectionIf there is competition for resources among individuals that

vary… then THERE WILL BE NATURAL SELECTION.

Conclusion #3: EvolutionIF there is natural selection AND certain characteristics are heritable…

THEN there will be… EVOLUTION BY NATURAL SELECTION.

Conclusion #3: Evolution by Natural Selection

Observation 1

Observation 3Conclusion 1

Observation 4Conclusion 2

Observation 2

Conclusion 3

+

+

+

Set it up like this!

Move on to Next Set