TerminologyVariation- different individuals in a population have different characteristics Heritable characteristics- the variation in characteristics that can be inherited by offspring Fitness-the ability to survive and produce offspring which are capable of reproducing  Adaptation- a characteristic that increases an individual’s fitness Evolution by Natural Selection- heritable adaptive characteristics become more common in a population over many generations 

What is What is Evolution?Evolution?

Simply put: all of the changes that have transformed life over an immense time

A biological history of life on Earth!

Phylogenic Tree

All life on Earth is united by evolutionary history; we are all evolutionary cousins — twigs on the tree of life.

Phylogenetic Systematics is the formal name for the field within biology that reconstructs evolutionary history and studies the patterns of relationships among organisms.

Terms to discuss before we start:

Speciation

Speciation- formation of a new species through evolution

Adaptation

Adaptation- a feature that allows an organism to better survive in its environment

Fitness

Fitness- measure of the ability to survive and produce more offspring (compared to other members in the population in the same environment)

A little history…• Pretend you are living in the 1600s. Think about

the technology that is available. How much do you know/understand about the world around you?

• Theories moving through your village:– Species are fixed and permanent. They do not change.– Earth is less than 10,000 years old and hasn’t changed

much.

What is this? A fossil? Hmmm…• Mid 1700s: Georges Buffon studies fossils

– “I think Earth is older than 10,000 years…”– “These fossils resemble animals that are alive

today…but they aren’t exactly the same…”

• Early 1800s: Jean Baptist Lamarck

- “I think I know why…

- …life evolves (or changes).

- Species are not permanent. They adapt.

Jean Baptiste Lamarck1744-1829The Principle of Use and Disuse:New structures developed in anorganism during the course ofevolution because they were needed and unused structureswere lost.

Inheritance of Acquired Characteristics: Characteristics gained during a lifetime were passed onto offspring.

What is wrong with this theory?

CHARLES DARWIN(1809-1882)

• Sailed on the H.M.S Beagle- spent 5 years collecting data

• Extensive research on the Galapagos Islands (particularly with finches)

• Theory of Natural Selection

• Wrote The Origin of Species

Sir Charles Lyell 1797 -1875

Well-known geologist: proposed that gradual and observable geologic processes (erosion) can explain Earth’s physical features

Lyell's work formed the foundation of belief in a universe billions of years old.

His work heavily influenced Charles Darwin.

Darwin's concept of gradual evolution lacked an acceptable time frame until he embraced Lyell's old-earth theories.

Charles Darwin credits Thomas Malthus in formulating his theory of Natural Selection.

Thomas Malthus (1766-1834)

Malthus said: populations can grow much faster than the rate at which supplies of food and other resources can be produced.

DARWIN’S THEORY2 main points:1.Descent with Modification

-Species of organisms living on Earth today descended from ancestral species

= diversity of life!

http://homestudy.ihea.com/wildlifeID/043jackrabbit.htm http://www.animalspot.net/snowshoe-hare.html

DARWIN’S THEORY continued…2. Natural Selection

- in an environment, some individuals with inherited characteristics are better suited to the environment and leave more offspring

= “most fit”

http://en.wikipedia.org/wiki/Peppered_mothhttp://en.wikipedia.org/wiki/Peppered_moth

Example of natural selection:

2 color beetles: green & brown

Green beetles are eaten by birds more often because they are visible in the dirt.

Brown reproduce and thrive, green goes extinct.

Natural Selection Principles:

1. Genetic variation exists among individuals.

2. Reproductive ability of species causes populations to

increase.

3. Organisms compete for resources.

4. Offspring with most favorable traits most likely to survive.

EVIDENCE OF EVOLUTION

• Geologic record• Fossils• Comparative anatomy (homologous vs. analogous)• Vestigial structures• Comparative Embryology• Comparative Cytology • Macromolecules

Geological Record: Through radioactive dating the oldest rocks in the earth’s crust, the age of the earth is 4.5 – 5 billion years old.http://video.pbs.org/video/1978170520/

Fossils: Traces of once living organisms. Fossils found in the upper strata of sedimentary rock are younger than thoseFound in the lower strata

In Rock

In Amber In Icehttp://www.youtube.com/watch?v=JZ7f-C83X2Y

Petrifaction

Top 15 Cloneshttp://www.youtube.com/watch?v=qJ9Syd3GqQc

Comparative Anatomy: Homologous Structures

Same structure, different function

Human Cat Whale Bat

Evidence that these organisms

evolved from the same ancestor

Analogous Structuresdifferent structure BUT same function

Butterfly Wing Bat Wing

Both fly, but did NOT evolve from same ancestor

Vestigial Structures: Structures in an organism through evolution have been lost or reduced in size because they wereno longer necessary trait for survival.

Comparative Embryology Comparative Cytology

Comparative Biochemistry- The chemical composition of insulinFound in sheep is almost identical to the insulin found in humans.Evidence of common ancestry.

Embryology

• Same group of embryonic cells develop in same order and in similar patterns in all vertebrates.

• Tail, pharyngeal

pouches, buds

Macromolecules• DNA base sequence similarities

• The more similar the biochemistry, the more closely related the organisms are.

• Human and chimp hemoglobin differs by one amino acid.

Patterns of Evolution

-Coevolution

-Convergent Evolution

-Divergent Evolution

CoevolutionChange of 2 or more species evolve in response to changes in each

other- dependent on each other = selective pressures

• Predators and prey• Parasites and hosts• Plants and pollinators

EXAMPLE: hummingbird feeds on nectar of flower, slender beak, pollen gets stuck on birds face: flowers are light in color, fruity odor

**Find another example of coevolution. Be specific in the organisms you list.

Convergent Evolution• Evolve similar traits, but are not related; when

environment selects similar phenotypes

Example:

• sharks and porpoises - not related, but look similar

**Would convergent evolution result in homologous structure or analogous structures? Explain.

Divergent Evolution• Closely related species evolve in different

directions, become increasingly different

• (may end up in new species)– Geographic isolation– Reproductive isolation (i.e Galapagos finches)– Adaptive radiation– Artificial selection (i.e. domestic dogs)

All members of the species Brassica oleracea

Same species?

Spilogale putorius Spilogale gracilis

What is a “species”?

• Population, or group of populations, whose members have the ability to breed with one another in nature and produce fertile offspring

Microevolution

Evolution involving small-scale changes, Generation Generation changes

i.e. within the species level, occurring over a short period of time that results in the formation of new subspecies.

Macroevolution

A process thought to produce relatively large (macro) evolutionary change within biological organisms.

Over long periods of time. Can’t be observed directly.Evident in the fossil record.

New species. Extinction. Evolution of features.

New species = More diversity• What is biodiversity?

• Why is biodiversity important?

Geographic IsolationA body of water or mountain range separates a population of a speciesresulting in evolution of new species.

Reproductive Isolation Some sort of barrier that keeps two species from interbreeding.-Timing (i.e. different mating seasons)-Behavior (i.e. courtship behaviors)-Habitat (i.e. lake bottom vs. surface)-Other (i.e. incompatible reproductive structures; producing

infertile offspring)

Adaptive RadiationSpecies adapt to different environments and result in diverse separate species

-Hawaiian Islands are a good example- about 4,000 km from nearest continent-each island is physically diverse- due to differences in altitudes and rainfall-there are many native species there that are found nowhere else in the world

Asio flammeus sandwichensisLasiurus cinereus semotus

– Artificial selection• Breeders developing many varieties of

domesticated animals in a few generations• Plant varieties, such as kale and broccoli,

developed from wild cabbage

Artificialselection inchickens:“Big Bird”

Artificialselection inBrassicaoleracea

Antibiotic Resistance

Molecular biology• Biochemical pathways• Genetics:Did humans evolve…..??????

Microbiology: TB and antibiotic resistance…….

Artificial Selection Activity 

1. Use the stick worm activity to write your own description of Natural Selection to show me that you understand how variation, adaptation, selective forces and reproduction play a role in natural selection and thus evolution.

2.  Write a paragraph describing how artificial selection supports the theory of evolution. Be sure to use and underline the VIST Terms (variation, inheritance, selection, time) in explanation.

3.  Provide 3 examples of how artificial selection was used (at least 1 plant and 1 animal) to create a current product you use/consume or see in every day life.  Do these selected organisms have economical advantage? Support with evidence.

4. In your own words write a concise definition for evolution.