EVOLUTION: VOCABULARY PART 1 EVOLUTION is ______Change_______ over _____time_________.

EVOLUTIONARY THEORY is an explanation of phenomena supported by a collection of scientific __facts_, ___observation_____ and____hypothesis.

FOSSILS are _____preserved__remains_____ of ___ancient___ organisms found in __ sedimentary rock (soil type).

NATURAL VARIATIONS are differences among individuals of a species.

ARTIFICIAL SELECTION- humans select from natural variations that they find most useful .

STRUGGLE FOR EXISTENCE is the competition to obtain __food_, living space , and other necessities.

FITNESS is the ability to survive and reproduce in its specific environment .

ADAPTATION is any inherited characteristic that increases an organism’s chance of survival .

SURVIVAL OF THE FITTEST –individuals that are better suited to their environment survive and reproduce.

NATURAL SELECTION – when the best survive and pass on beneficial characteristics to offspring without human control; overtime may change population.

VARIATIONS – differences in traits within a species .

HOMOLOGOUS STRUCTURE- have different functions but develop from same embryonic tissues.

VESTIGIAL ORGAN is an organ that serves no useful function.

EXTINCTION - end of a species

CH 15-1 NOTESEVOLUTION2 TYPES: GEOLOGIC- change of earth over time .(biological)ORGANIC- changes in living things over time.

TWO IMPORTANT SCIENTISTS: 1. Darwin

2. Lamarck

JEAN-BAPTISTE LAMARCKGOOD• 1st to recognize that living things change over time .

• all species were descended from other species

• organisms adapted to environment

NOT SO GOOD• by selective use or disuse of organs, organisms acquired or Lost certain traits during their lifetime.

• traits were passed on to their offspring.

• over time there was a change in the species.

HINT the phrase “ acquired characteristics” is associated with Lamarck

CHARLES DARWINDeveloped theory of evolution based on VARIATION and NATURAL SELECTION.

•OVERPRODUCTION- production of more offspring than can

survive

•COMPETITION- members of each species must fight for

limited resources

•SURVIVAL of the FITTEST- individuals best adapted for their

environment survive

•REPRODUCTION- those individuals that survive reproduce,

and pass on successful

characteristics to offspring

•SPECIATION- formation of new species over time

-natural selection causes changes in

characteristics of species over time

-new species arise, old species

disappear

-species today descended with

modifications from species in past

•COMMON DESCENT- all organisms on Earth are united into

a single tree of life

EVIDENCE OF EVOLUTION

1. FOSSIL RECORD

•Earth is many millions of years old and is slowly

changing over time

•Fossils found in different layers of rock formed at

different times in history

2. GEOGRAPHIC DISTRIBUTION of LIVING SPECIES

•Common ancestry - new species develop from

adapting to specific environment

3. HOMOLOGOUS STRUCTURES

•Similar forms with different functions

4. SIMILARITIES IN EARLY DEVELOPMENT

•Different organisms have similar early development

http://www.teachersdomain.org/resources/tdc02/sci/life/evo/howhappens/index.html

You should have a hand out and data paper to fill in after you finish watching the movie. It will be graded as a project.

Chapter 16 Vocabulary

Adaptive value– the value to the population of an adaptation

Common Descent – organisms have a common ancestor

Struggle for existence – every organism struggles to survive, but only the fittest survive

Genetic equilibrium – situation in which allele frequencies remain constant

Reproductive isolation – organisms become unable to breed and produce fertile offspring

Speciation – a new species is formed

Genetic Drift – random change in allele frequencies that occurs in small populations

Disruptive selection – Form of natural selection where the 2 ends of the distribution curve are favored

Geographic isolation – form of reproductive isolation where 2 populations are separated physically

Behavioral isolation – form of reproductive isolation in which 2 populations have differences in courtship rituals that prevents interbreeding

EVOLUTION NOTES CHAPTER 16I. Darwin and DNA

Darwin did not know how heredity worked.Two factors he couldn’t explain:

1. Source of variation2. how inheritable traits were passed from one generation to the next

II Gene PoolsCombined genetic information of all the Members of a particular population.

Two main sources of genetic variation:1. Mutations -- change in sequence of DNA2. Genetic shuffling -- sexual reproduction(crossing-over)

III Genetic DriftIn small populations, an allele becomes more or Less common simply by chance.

IV When will evolution NOT occur?When there is genetic equilibrium -- alleleFrequencies remain constant .* if the allele frequencies do not change , thepopulation will not evolve.

Hardy-Weinburg principleFIVE conditions to maintain genetic equilibrium:

1. random mating2. large population3. no movement in or out of population4. no mutations5. no natural selection

ORIGIN OF LIFE *Current scientific view of events on early Earth

Primitive Earth1. Surface- sea of molten rock

2. Atmosphere- gases such as: hydrogen cyanide, carbon dioxide, carbon monoxide, nitrogen, hydrogen sulfide, water NO OXYGEN

3. Earth cooled enough to form crust ; violent volcanic activity

4. More cooling caused thunderstorms which created oceans.

How could organic molecules have evolved under these conditions?

Stanley Miller and Harold Urey simulated conditions on early Earth in the laboratory.

• Filled flask with hydrogen , methane ,ammonia, and water.

• Passed electric sparks through mixture of gases to simulate lightning

• Over a few days, several amino acids began to accumulate (organic compounds)

Sidney Fox demonstrated iteractions among these

organic molecules. These experiments joined Miller’s

organic compounds into aggregates , similar in form

to “ cell-like ” structures.

These first aggregates were called heterotrophs and were

similar to prokaryotic bacteria and had the ability to reproduce.

These discoveries created the heteotroph hypothesis.

Heterotrophs -- anaerobic respiration -- CO2 given offAutotrophs -- O2 given off – aerobic respiration

Excessive oxygen in the atmosphere produced an ozone layer which gave protection from ultraviolet radiation.

Some anaerobic species became extinct, while others adapted to the environmental change.

PATTERNS of EVOLUTION

1. Punctuated equilibrium• long, stable periods of no change interruptedby brief periods of more rapid change which produced many new species

2. Gradualismevolution occurs gradually, slowly and continuously

Adaptive Radiation

Divergent Speciation