Change in organisms over a long time What is evolution?

Change in organisms over a long time

What is evolution?

In order for evolution to occur, there must be NATURAL VARIATION present.

Lamark Species strive for perfection and complexity“Use it, or lose it” Acquired traits are passed on to offspring

Darwin proposed the theory of NATURAL SELECTION

DarwinStudied the Galapagos finches and examined how they evolved. He used the term: “Survival of the Fittest”

What is the type of adaptation that new species originate from one ancestor like Darwin’s finches?

“Tweak the Beak”

Adaptive Radiation

Darwin said that the ability of an organism to survive and reproduce in its environment is called its FITNESS!

What is the type of evolution where there is a long, steady evolution in a species?

Gradualism

Name the type of evolutionary change where there is a long period of steady evolution and then a sudden event such as the ice age or a major volcano eruption?

Punctuated Equilibrium

Structures from same ancestor, with same structure, but with different species are called Homologous structures. Homo=same

Structures from different ancestors, different species but perform same function are calledAnalogous Ana=“not” structures.

Vestigial organs are ones that are reduced in size and have no known function any longer.

What is a fossil?

Preserved remains of a living organism

1. No mutations2. No emigration/immigration3. No natural selection4. Must be a large population5. Random mating must occur

Genetic Equilibrium will occur if ALL of the following 5 conditions must exist (this is highly unlikely to ever happen)

Hardy-Weinberg Equilibrium Principle

All the combined alleles in a population (species living in an area) is called the gene pool.

What is the gene frequency change in a small population which is due to chance? Genetic Drift

What is it called when a few organisms leave their original habitat and start a new colony with fewer allele frequency than the original colony?

FOUNDER EFFECT

A species is an organism that can reproduce and produce fertile offspring.

Mules are not a species

Horse Donkey

Natural Selection: Nature selects the best traits for survival Changes allele frequency

Artificial selection: Man selects best traits to breed.

1. Behavioral Isolation: Traits or habits preventing reproduction (the mating song or dance of a bird)

2. Geographical Isolation: Land separation of individuals in a species keeping them from reproducing (oceans, rivers, canyons, etc.)

3. Temporal Isolation: Mating season is different such as winter vs. spring or April vs. October or night vs. day.

3 Types of Reproductive Isolation

Name the following graphs and describe what is happening.

1

3

2

Stabilizing: The average (middle) individuals of a species are fittest.

Disruptive: The individuals at the outer ends are fittest.

Directional: The individuals at one end are fittest.

What is convergent evolution?Two species that had different ancestors but due to living in the same environment, they look alike such as the dolphin and shark.

What is divergent evolution?Two or more species have the same ancestor but have branched off into new species.

What type of evolution is this when one species must evolve along with another for survival?

Coevolution