Unit 7 Review and Quiz

Developed the Theory of Natural Selection from his journey around the world.
Specifically his studies of the Galapagos Island Finches

Charles Darwin

Evolution

The change in a species over time

4 Truths of Natural Selection
1. Genetic Variation- there must be variants of a trait for species to be different
2. Struggle for existence- competition must exist
3. Organisms with traits best adapted to the environment will survive.
4. Surviving organisms will reproduce and the offspring will likely have the same beneficial trait increasing the frequency of that trait.

Natural Selection-
Survival of the Fittest

Multiple Choice

Which result is most likely to occur to the beetle population due to predation over time?

• the number of light beetles will increase

• there will be more dark beetles

• The number of light beetles will decrease

• The dark beetles will move away

Multiple Choice

Some salamander species have developed the ability to insert its DNA into the DNA of other species of salamanders. How will this be helpful to the salamander species

• by decreasing mutations

• by increasing genetic diversity

• by making DNA more similar across the population

• by creating genetically identical individuals

Mechanisms of Evolution

1.Natural Selection

2. Genetic drift

3. Gene flow

4. Recombination

5. Geographical Isolation

6. Mutations

Geographical Isolation

Also known as biogeography

Results in populations being separated by physical barriers

This results in the species not being able to interbreed

Speciation may occur as a result after many many generations of separation

Genetic Drift

The result of a random occurrence such as a meteor shower that kills off or reduces a certain trait.

Natural Selection

The selection by nature of traits that are most suitable for the environment

Also known as "Survival of the Fittest"

Natural Selection

If an organism is able to survive, then it can reproduce and pass on it's favorable trait(s) to its offspring.

EX: The black peppered moth was better able to survive after the industrial revolution, therefor the population of black peppered moths increase.

Variations

Variation within a species must be present in order for natural selection to take place. These variations can be caused by

Mutations

Gene flow

Recombination

Recombination

Also known as Crossing Over during the formation of the gametes in meiosis.

Results different combinations of genetic material

Gene Flow

The movement (flow) of genes from one population to another

Multiple Choice

Less dominant male baboons may leave their troop to find females in another troop. This is called

• gene flow

• genetic drift

• recombination

• natural selection

Multiple Choice

In order for natural selection to occur __ must be present within the population

• genes

• Lots of water

• Variations

• Lack of variations

Multiple Choice

The crossing over of chromosomes during meiosis is called __

• gene flow

• genetic drift

• recombination

• mutation

Multiple Choice

A forrest fire kills 1/3 of the population of rabbits leaving behind only rabbits with white and grey fur. No rabbits with dark gray fur survive. This is an example of _

• gene flow

• genetic drift

• recombination

• natural selection

Multiple Choice

Dr. Allison determined that individuals with the sickle cell allele were resistant to malaria resulting in more individuals from areas where malaria is widespread having sickle cell. This is an example of

• gene flow

• genetic drift

• recombination

• natural selection

Multiple Select

Fitness of an organism is best described as ___ and ___

• being able to survive

• being the strongest

• reproducing

• running real fast

Common Ancestry

Scientist believe that we all came from a common ancestor. Thus we all have similarities in one way or another

Evidence ofCommon Ancestry

Science must rely solely on data and solid evidence. The evidence to support common ancestry are:

1. Homologies

   1. anatomical b. developmental c. molecular (DNA/proteins)

2. Fossils

3. Biogeography

Biogeography

Similarities in organisms that are separated by large geographical barriers

Fossils

Similarities in fossils of organisms that indicated they are closely related.

Usually have periods of gradualism with transitional fossils to show the slow change. (Darwin)

Sometimes there is a period of stasis followed by sudden rapid change with few transitional fossils known as punctuated equilibrium (Eldredge & Gould)

Anatomical homologies

Similarities in the structures (bones, organs) of different species even if those structures do different things.

Ex: The arm of a human and the fin of a whale

Developmental homologies

Also known as Embryological homologies

Similarities in the embryos of different organisms

Molecular homologies

Similarities in the DNA of organisms

Sometimes similariities in proteins are mentioned, but remember that proteins are coded for by the DNA.

Multiple Choice

This is an example of

• developmental homology

• molecular homology

• fossil evidence

• anatomical homology

Multiple Choice

This is evidence that that the bat and mouse _

• both hang upside down to sleep

• both have arms

• Have a common ancestor

• both eat insects

Multiple Choice

According to the hemoglobin protein, which two organisms are most closely related?

• Human and chicken

• chicken and frog

• Frog and Monkey

• Human and monkey

Multiple Choice

This is an example of _

• Molecular homology

• Developmental homology

• Biogeography

• Anatomical homology

Multiple Choice

The fact that all of these embryos have gill slits and tails is evidence that _

• They all live under water

• They all have a common ancestor

• They all have tails when born

• They are all mammals

Multiple Choice

Which one of these demonstrates gradulaism?

Multiple Choice

Which one of these demonstrates punctuated equilibrium?

Multiple Choice

When the masses of land of Pangea began separating living organisms were permanently separated leading to the evolution of those organsims. This is called _

• molecular homology

• developmental homology

• Fossil evidence

• Biogeography