Change in organisms over a long time

Change in organisms over a long time

What is evolution?

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

James Hutton Charles Lyell

Hutton and Lyell were geologists who stated the Earth was MILLIONS of years old, not thousands.

Who wrote about human population growth eventually exceeding the Earth’s resources threatening our species survival? MALTHUS

Most species produce many more offspring than the resources in that area can handle. This leads to a situation called:

Struggle for Existence

Lamark - “Lamark missed the mark” 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”

Adaptive Radiation is the type of adaptation that new species originate

from one ancestor like Darwin’s finches (Tweak the Beak)

“Tweak the Beak”

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

Punctuated Equilibrium - the type of evolutionary change where there is a long period of steady evolution and then a sudden event such as a volcano eruption causes change

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

Structures from different ancestors, 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. Who studies fossils? Paleontologists2. What is it called to date a fossil?

Relative Dating : position of fossil in Earth’s rock layers

3. Where are the oldest fossils found in soil? Lowest rock layers

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 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 or random event?

Genetic Drift

Founder Effect

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

Mules are not a species

Horse Donkey

Why do some species evolve faster than others? Example: antibiotic resistant bacterial? (don’t respond to an antibiotic)

Bacteria reproduce so rapidly they can mutate (change/evolve) faster than larger organisms that reproduce slower.

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.

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

Peppered Moth &Melanism

Best environment for white moths to avoid being eaten by birds

Best environment for black mothsto avoid being eaten by birds

Environmental Pressure!

Look at these embryos. Which groups came from the same ancestors? “Embryology”

3 Ways to Identify Similar Ancestor

FOSSILS

EMBRYOLOGY

DNABiochemistry

What lead to the increase in oxygen on the Earth’s surface millions of years ago?

PhotosyntheticBacteria