5/6/13 Living Environment

5/6/13 Living Environment1. Attendance2. Tests: Shantese, Jamila, Lakota3. I have storybooks from:

Heather, Julisa, Mawazo, Destiny, Calisa, Shantese

4. I have Finch labs from:Shantese,Trev, Iesha, Jamila, Samiyah, Naima, Calisa, Lakota, Julisa, Mawazo, Destiny

Genetic EngineeringGenetic Engineers can

alter the DNA code of living organisms.

Selective Breeding

Recombinant DNA

PCR

Gel Electrophoresis

Transgenic Organisms

Selective BreedingBreed only those

plants or animals with desirable traits

People have been using selective breeding for 1000’s of years with farm crops and domesticated animals.

Recombinant DNAThe ability to

combine the DNA of one organism with the DNA of another organism.

Recombinant DNA technology was first used in the 1970’s with bacteria.

Recombinant Bacteria1. Remove bacterial DNA (plasmid).

2. Cut the Bacterial DNA with “restriction enzymes”.

3. Cut the DNA from another organism with “restriction enzymes”.

4. Combine the cut pieces of DNA together with another enzyme and insert them into bacteria.

5. Reproduce the recombinant bacteria.

6. The foreign genes will be expressed in the bacteria.

Benefits of Recombinant Bacteria1. Bacteria can make human insulin or human

growth hormone.

2. Bacteria can be engineered to “eat” oil spills.

The DNA of plants and animals can also be altered.

PLANTS

1. disease-resistant and insect-resistant crops

2. Hardier fruit

3. 70-75% of food in supermarket is genetically modified.

How to Create a Genetically Modified Plant

1.Create recombinant bacteria with desired gene.

2. Allow the bacteria to “infect" the plant cells.

3. Desired gene is inserted into plant chromosomes.

What do you think about eating genetically modified foods?

Genetically modified organisms are called transgenic organisms.

TRANSGENIC ANIMALS

1. Mice – used to study human immune system

2. Chickens – more resistant to infections

3. Cows – increase milk supply and leaner meat

4. Goats, sheep and pigs –

produce human proteins in their milk

Human DNA in a Goat

Cell

This goat contains a human gene that codes for a blood clotting agent. The blood clotting agent can be harvested in the goat’s milk.

.

Transgenic Goat

Desired DNA is added to an egg cell.

How to Create a Transgenic Animal

Ha Ha Ha!

Genetic Engineering and Crime Scenes……

Gel Electrophoresis

This technology allows scientists to identify someone’s DNA!

Steps Involved in Gel Electrophoresis1. “Cut” DNA sample with

restriction enzymes.

2. Run the DNA fragments through a gel.

3. Bands will form in the gel.

4. Everyone’s DNA bands are unique and can be used to identify a person.

5. DNA bands are like “genetic fingerprints”.

http://www.dnalc.org/ddnalc/resources/electrophoresis.html

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EVOLUTION

Chapter 15

Charles Darwin

Question for Thought

Earth has millions of other kinds of organisms of every imaginable shape, size, and habitat.

This variety of living things is called biological diversity. How did all these different organisms arise?

How are they related?

In your own words, describe what YOU think the theory of evolution means…

Darwin’s Theory of Evolution

Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms.

A scientific theory is a well-supported testable explanation of phenomena that have occurred in the natural world.

How do you think Darwin came up with his theory?

Voyage of the Beagle

Voyage of Beagle

Dates: February 12th, 1831 Captain: Charles Darwin Ship: H.M.S. Beagle Destination: Voyage around the world. Findings: evidence to propose a

revolutionary hypothesis about how life changes over time

Patterns of Diversity

Darwin visited Argentina and Australia which had similar grassland ecosystems.

those grasslands were inhabited by very different animals.

neither Argentina nor Australia was home to the sorts of animals that lived in European grasslands.

Patterns of Diversity

Darwin posed challenging questions. Why were there no rabbits in Australia, despite the

presence of habitats that seemed perfect for them?

Why were there no kangaroos in England?

Living Organisms and Fossils

Darwin collected the preserved remains of ancient organisms, called fossils.

Some of those fossils resembled organisms that were still alive today.

Living Organisms and Fossils Others looked completely unlike any creature he had

ever seen.

As Darwin studied fossils, new questions arose. Why had so many of these species disappeared?

How were they related to living species?

Fossils

The Galapagos Island The smallest, lowest islands were hot,

dry, and nearly barren-Hood Island-sparse vegetation

The higher islands had greater rainfall and a different assortment of plants and animals-Isabela- Island had rich vegetation.

The Galapagos Island

Darwin was fascinated in particular by the land tortoises and marine iguanas in the Galápagos.

Giant tortoises varied in predictable ways from one island to another.

The shape of a tortoise's shell could be used to identify which island a particular tortoise inhabited.

Animals found in the Galapagos Land Tortoises

Darwin Finches

Blue-Footed Booby

Marine Iguanas

Animals

The Journey Home

Darwin Observed that characteristics of many plants and animals vary greatly among the islands

Hypothesis: Separate species may have arose from an original ancestor

Ideas that shaped Darwin’s Thinking James Hutton: 1795 Theory of

Geological change Forces change

earth’s surface shape

Changes are slow Earth much older

than thousands of years

Ideas that Shaped Darwin’s Thinking Charles Lyell Book: Principles of Geography Geographical features can be built up or

torn down Darwin thought if earth changed over time,

what about life?

Lamarck

Lamarck’s Theory of Evolution

Tendency toward Perfection(Giraffe necks)

Use and Disuse (bird’s using forearms)

Inheritance of Acquired Traits Are you still paying Attention?

Population Growth Thomas Malthus-

19th century English economist

If population grew (more Babies born than die) Insufficient living

space Food runs out Darwin applied this

theory to animals

Publication of Orgin of Species Russel Wallace wrote

an essay summarizing evolutionary change from his field work in Malaysia

Gave Darwin the drive to publish his findings

Natural Selection & Artificial Selection Natural variation--differences among

individuals of a species

Artificial selection- nature provides the variation among different organisms, and humans select those variations they find useful.

Evolution by Natural Selection

The Struggle for Existence-members of each species have to compete for food, shelter, other life necessities

Survival of the Fittest-Some individuals better suited for the environment

Struggle For Existence & Survival of The Fittest

Natural Selection Over time, natural

selection results in changes in inherited characteristics of a population. These changes increase a species fitness in its environment

Descent Descent with Modification-Each living organism has

descended, with changes from other species over time Common Descent- were derived from common ancestors

Evidence of Evolution The Fossil Record

Geographic Distribution of Living Things

Homologous Body Structures

Similarities in Early Development

Evidence for Evolution The Fossil Record-

Layer show change Geographic

Distribution of Living Things



Evidence of Evolution The Fossil Record Geographic

Distribution of Living Things-similar environments have similar types of organisms



Homologous Structures

Homologous Structures-structures that have different mature forms in different organisms, but develop from the same embryonic tissue

Evidence for Evolution

Vestigial organs-organs that serve no useful function in an organism

i.e.) appendix, miniature legs, arms


Summary of Darwin’s Theory Individuals in nature differ from one

another

Organisms in nature produce more offspring than can survive, and many of those who do not survive do not reproduce.

Summary of Darwin’s Theory

Because more organisms are produce than can survive, each species must struggle for resources

Each organism is unique, each has advantages and disadvantages in the struggle for existence

Summary (cont.)

Individuals best suited for the environment survive and reproduce most successful

Species change over time

Summary (cont.)

Species alive today descended with modification from species that lived in the past

All organisms on earth are united into a single family tree of life by common descent

Regents Biology 2006-2007

Insect eaters

Bud eater

Seed eaters

Cactuseater

Warblerfinch

Tree

finc

hes Ground finches

Darwin & Evolution by

Natural Selection

Regents Biology

Charles Darwin Proposed a way how

evolution worksHow did creatures

change over time? by natural selection

Collected a lot of evidence to support his ideas 1809-1882 British naturalist

Regents Biology

Robert Fitzroy

Voyage of the HMS Beagle Invited to travel around the world

1831-1836 (22 years old!) makes many observations of nature

main mission of the Beagle was to chart South American coastline

Regents Biology

Voyage of the HMS Beagle Stopped in Galapagos Islands

500 miles off coast of Ecuador

Regents Biology

GalapagosRecently formed volcanic islands. Most of animals on the Galápagos live nowhere else in world, but they look like species living on South American mainland.

800 km west of Ecuador

Regents Biology

Many of Darwin’s observations made him wonder… Why?

Darwin asked:Why were these creatures found only on the Galapagos Islands?

Darwin found…many unique species

Regents Biology

present day Armadillos

Darwin found:Evidence that creatures have changed over time

ancient Armadillo

Darwin asked:Why should extinct armadillos & modern armadillos be found on same continent?

Darwin found…clues in the fossils

Regents Biology

Darwin found:Different shells on tortoises on different islands

Darwin asked:Is there a relationship

between the environment & what an animal

looks like?

Regents Biology

QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

Finch? Sparrow?

Woodpecker? Warbler?

Darwin found… birds

Finch? Sparrow?


Darwin found:Many different birds on the Galapagos Islands.

He thought he found very different kinds…

Regents Biology

Darwin was amazed to find out: All 14 species of birds were finches…



Finch? Sparrow?


Finch? Sparrow?


But Darwin found… a lot of finches

Large ground finch

Small ground finch

Warbler finch Tree finch

But there is only one species of finch on the mainland! Darwin asked:

If the Galapagos finches came from the mainland, why are they

so different now?

Regents Biology



Finch? Sparrow?


The finches cinched it!

Large ground finch

Small ground finch

Warbler finch Tree finch

Big seed eater Small seed eater

Insect eater Leaf & bud eater

Darwin said:Ahaaaa!

A flock of South American finches

were stranded on the Galapagos…

Darwin found: The differences between species of finches were associated with the different food they ate.

different beaks are inherited variations

serve as adaptationsthat help birds compete for food

these birds survive & reproduce

pass on the genes for those more fit beaks

over time nature selected for different species with different beaks

Regents Biology

Relationship between species (beaks) & food

Regents Biology

Darwin’s finches Darwin’s conclusions

variations in beaks differences in beaks in the original flock adaptations to foods available on islands

natural selection for most fit over many generations, the finches were

selected for specific beaks & behaviors offspring inherit successful traits

accumulation of winning traits:both beaks & behaviors

separate into different species

Regents Biology

Warbler finch

Woodpecker finch

Small insectivorous

tree finchLarge

insectivoroustree finch

Vegetariantree finch

Cactus finch

Sharp-beaked finch

Small groundfinch

Mediumground finch

Large groundfinch

Insect eaters

Bud eater

Seed eaters

Cactuseater

Warblerfinch

Tree

finc

hes Ground finches

variation natural selection for best survival & reproduction

From 1 species to 14 species…

Regents Biology

LaMarck evolution by acquired

traits creatures developed

traits during their lifetime give those traits to their

offspring example

in reaching higher leaves giraffes stretch their necks & give the acquired longer neck to offspring

not accepted as valid

Earlier ideas on Evolution

Regents Biology

Darwin’s view of Evolution Darwin

giraffes that already have long necks survive better

leave more offspring who inherit their long necks variation selection &

survival reproduction &

inheritance of more fit traits

Regents Biology 2006-2007

Asking Questionsis a good adaptation!

Regents Biology

present day Sloth

Darwin found… more fossils

Darwin asked:Why should extinct sloths & modern sloths be found on the same continent?

(extinct) Giant ground sloth

Darwin found:Evidence that creatures have changed over time

Chapter 17

The History of Life

Fossil imprint

The Fossil Record

• Provides evidence about the history of life on Earth.

• It also shows how different groups of organisms, including species, have changed over time.

Relative Dating

Can determine

Is performed by

Drawbacks

Absolute Dating

Comparing Relative and Absolute Dating of Fossils

Imprecision and limitations of age data

Difficulty of radioassay laboratory methods

Comparing depth of a fossil’s source stratum to the position of a reference fossil or rock

Determining the relative amounts of a radioactive isotope and nonradioactive isotope in a specimen

Age of fossil with respect to another rock or fossil (that is, older or younger)

Age of a fossil in years

Relative vs. Absolute Dating

Principle of Superposition• In an undisturbed sequence of

sedimentary rocks, the oldest rocks are on the bottom with the most recent on top.

How fossils are formed

Water carries small rock particles to lakes and seas.

Dead organisms are buried by layers of sediment, which forms new rock.

The preserved remains may later be discovered and studied.

Geological Time Scale

• After the Precambrian Time, the time scale is divided into eras, which are subdivided into periods.

Era Period TimePermian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

(millions of years ago)Era Period Time (millions of

years ago)Era Period Time (millions of years ago)

290 – 245

360–290

410–360

440–410

505–440

544–505

1.8–present

65–1.8

145–65

208–145

245–208

Quaternary

Tertiary

Cretaceous

Jurassic

Triassic

Vendian 650–544

Geological Time Scale

• The major eras are Paleozoic, Mesozoic, and Cenozoic.


Carboniferous

Devonian

Silurian

Ordovician

Cambrian



290 – 245

360–290

410–360

440–410

505–440

544–505

1.8–present

65–1.8

145–65

208–145

245–208

Quaternary

Tertiary

Cretaceous

Jurassic

Triassic

Vendian 650–544

Geologic Time Scale

• Each period hosts significant evolutionary changes to species diversity and extinction.


Carboniferous

Devonian

Silurian

Ordovician

Cambrian



290 – 245

360–290

410–360

440–410

505–440

544–505

1.8–present

65–1.8

145–65

208–145

245–208

Quaternary

Tertiary

Cretaceous

Jurassic

Triassic

Vendian 650–544

Glaciations; mammals increased; humansMammals diversified; grassesAquatic reptiles diversified; flowering plants; mass extinctionDinosaurs diversified; birdsDinosaurs; small mammals; cone-bearing plantsReptiles diversified; seed plants; mass extinctionReptiles; winged insects diversified; coal swampsFishes diversified; land vertebrates (primitive amphibians)Land plants; land animals (arthropods)Aquatic arthropods; mollusks; vertebrates (jawless fishes)Marine invertebrates diversified; most animal phyla evolvedAnaerobic, then photosynthetic prokaryotes; eukaryotes, then multicellular life

Cenozoic

Mesozoic

Paleozoic

PrecambrianTime

QuaternaryTertiaryCretaceousJurassicTriassicPermianCarboniferousDevonianSilurianOrdovicianCambrian

1.8–present65–1.8145–65208–145245–208290–245363–290410–363440–410505–440544–505650–544

Key EventsEra Period Time (millions of years ago)

Summary of major events (pg. 429-34)

Hypothesis of early Earth• Very hot surface from

colliding meteorites• Very hot planet core

from radioactive materials

• Volcanoes spewing lava and gases that helped to form the early atmosphere

Hypothesis of early Earth

• About 4.4 billion years ago, Earth might have cooled enough for the water in its atmosphere to condense.

• This might have led to millions of years of rainstorms with lightning, enough rain to fill depressions that became Earth’s oceans.

• The oldest rocks dated are 3.9 million years old.

Fossils: evidence of an organism that lived long ago that is preserved in

Earth’s rocks• Paleontologists

estimate that about 95% species are extinct from life’s origins.

• Climate and ancient geography can be determined from fossils.

Types of FossilsFossils Types Formation

Trace fossils

Casts

Molds

Petrified/Permineralized

fossilsAmber-Preserved orfrozen fossils

A trace fossil is any indirect evidenceA trace fossil is any indirect evidenceleft by an animal and may include afootprint, a trail, or a burrow.

When minerals in rocks fill a space left by a decayed organism, they makea replica, or cast, of the organism.

A mold forms when an organism isA mold forms when an organism isburied in sediment and then decays,leaving an empty space.

Petrified-minerals sometimes penetrateand replace the hard parts of an organism. Permineralized-void spacesin original organism infilled byminerals.At times, an entire organism was quickly trapped in ice or tree sap thathardened into amber.

What has been learned from fossils

• several episodes of mass extinction that fall between time divisions– mass extinction: an event that occurs when

many organisms disappear from the fossil record almost at once

• The geologic time scale begins with the formation of Earth about 4.6 billion years ago.

Precambrian – 87% of history• Oldest fossils about 3.4 billion years old

resembling cyanobacteria stromatolites.• Stromatolites still form today in Australia

from mats of cyanobacteria. • The stromatolites are evidence of the

existence of photosynthetic organisms on Earth during the Precambrian.

• Only prokaryotic life found in fossil record

End of Precambrian – 543 MYA• multicellular eukaryotes,

such as sponges and jelly-fishes, diversified and filled the oceans

Paleozoic and Cambrian Period

• Paleozoic Era: more animals and plants– Early: fishes, aquatic vertebrates, ferns– Middle: amphibians– Late: reptiles and mass extinction

– Cambrian Period: oceans teemed with many types of animals, including worms, sea stars, and unusual arthropods

Mesozoic - 248 MYA• Triassic Period: mammals and dinosaurs• Jurassic Period: dinosaurs and birds• Cretaceous Period: more mammals,

flowering plants, but mass extinction of dinosaurs 65 MYA

Continental drift

• Earth’s continents have moved during Earth’s history and are still moving today at a rate of about six centimeters per year.

• The theory for how the continents move is called plate tectonics.

Geologic Time Scale video

Click on image to play video.

Miller-Urey experiment showed one possible way for inorganic molecules to form organic molecules. Mixture of gases

simulating atmospheres of early Earth

Spark simulating lightning storms

Condensation chamber

Cold water cools chamber, causing droplets to form

Water vapor

Liquid containing amino acids and other organic compounds

How eukaryotic cells evolved

• Lynn Margulis proposed the endosymbiotic theory.

Aerobic bacteria

Ancient Prokaryotes

Ancient Anaerobic Prokaryote

Primitive Aerobic Eukaryote

Primitive Photosynthetic Eukaryote

Chloroplast

Photosynthetic bacteria

Nuclear envelope evolving Mitochondrion

Plants and plantlike protists

Animals, fungi, and non-plantlike protists

Endosymbiotic theory• Heterotrophic bacteria have plasmids

(DNA loop) & simple ribosomes in their cytoplasm

• Mitochondria have circular DNA & bacteria-like ribosomes

• So…Eukaryotic cells may have engulfed prokaryotic cells & by mutualism created the “first mitochondria.”

• Autotrophic bacteria are Cyanobacteria with chlorophyll

• So, Eukaryotic cells may have engulfed prokaryotic cyanobacteria & by mutualism created the “first chloroplast.”

• Heterotrophic symbiosis = symbiont produces ATP, host uses ATP, host protects symbiont

• Autotrophic symbiosis = symbiont produces sugar, host uses sugar, host protects symbiont

• Relationships may allow host to live longer & reproduce more, thus over time creating more complex eukaryotic cells

Evolution of life video

Click on image to play video.

Macroevolution Large-scale evolutionary patterns and

processes that occur over long periods of time. Includes 6 topics:ExtinctionAdaptive radiationConvergent evolutionDivergent evolutionPunctuated equilibriumChanges in developmental genes

Patterns of evolution• Darwin believed that

organisms evolved gradually.

• Niles Eldredge and Stephen Jay Gould believed punctuated equilibrium is how organisms evolved, periods of rapid evolution followed by periods of stasis.

Adaptive Radiation

• Single species or small groups of species evolved into diverse forms living in different ways.

Convergent Evolution

• Adaptive radiation can produce unrelated organisms that look similar due to similar environments.

Coevolution • Example: “This butterfly acquires a cardiac glycoside from members of the genus Asclepias. Because of their milky sap, these are commonly referred to as milkweed plants. The plants produce this toxin as a defense against herbivory, but the Monarch has the ability to sequester the toxin in fatty tissues so that it makes the butterfly unpalatable while not poisoning the butterfly.”

http://ecology.botany.ufl.edu/ ecologyf02

The process by which two species evolve in response to changes in each, other over time.

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5/6/13 Living Environment