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67 Cards in this Set

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It occurs with the change in a gene pool of a species which is passed down from generation to generation.


A biological ability of an organism to survive, reproduce and pass it's genes to the next generation.

Common Descent

Organisms share a common descent if they have a common ancestor.


The adjustment of an organism's behaviour and structure to become more suited to their environment.


The preserved remains of organisms from a past geological age.

Geological Time Scale

A system of chronological measurement that relates layers of archeological remains to time.

Relative Dating

The science of determining the relative order of past historical events.

Radioactive Elements

Elements that possess a property that allows them to spontaneously emit energetic particles.

Absolute Dating

It is the process used to determining an approximate age in archeology and geology.

Half Life

It is the time required for half the quantity of a substance in an organism to be metabolized. Or the time required for the radioactivity of a material to be taken in by a living organisms.

Time Periods

Era --> Periods --> Epoch

Sediment Rock

A type of rock that is formed by the deposition and solidification of sediment, often in layers.


A scientist who studies fossils.

Fossil Record

A term that refers to the total number of fossils that have been discovered.


An embyro is an unborn or unhatched organism that is in the process of development.

Homologous Structure

~ Structures that are similar in structure and development, most likely due to sharing a common ancestor.

~ Ex. Bat wing, human forearm, sloth arm, monkey, whale flipper.

Vestigial Organ

~ Structure that had a purpose in a distant relative of an organism but it no longer pertinent to the organism today.

~ Ex. Human wisdom teeth, collar bones, human tail bone, appendix and ear muscles, male nipple, hip bones of a whale and python.

Analogous Structure

~ Structures in organisms that are different in structure and development but serve the same purpose.

~ Ex. Bird wing, bat wing, butterfly wing.


~ Stands for deoxyribonucleic acid

~ Double helix molecule that contains genetic information for the development of an organism.

Nitrogen Bases

Is a nitrogen compound with the chemical properties of a base that bonds nucleic acids together

Sugar-phospate backbone

The sugar-phospate backbone forms the structural frame of nucleic acids, this occurs as nucleotides are joined by bonds between a sugar of one nucleotide to the phosphate of the next, resulting in the backbone.

Complementary Base Pairing

~ Standard arrangement of bases in nucleotides in relation to their opposite pair.

~ A= Adenine & T= Thymine

~ G= Guanine & C= Cytosine

Double Helix

~ 'Double Helix' refers to the normal configuration of the structure of DNA. It consists of two helixes that wind on the same axis.

DNA Structure

~ Composed of many repeating units called nucleotides which are composed of a sugar (deoxyribose), phosphate group, nitrogen base (Which there are two types)


~ A double ring structure

~ A= Adenine & G= Guanine


~ A single ring structure

~ T= Thymine & C= Cytosine

Functions Of DNA

1. Replicate or make copies of itself. This is necessary so DNA may be passed on from cell to cell and from generation to generation.

2. Control the activities of the cell. This allows the cell to produce the visible characteristics of the individual and the species.

3. Undergo mutations. Permanent genetic changes are passed on to the offspring in order to account for the evolutionary history of life.


~ A building block of a nucleic acid (DNA)

~ Three parts: Sugar, Phosphate, Nitrogen Base

Embryonic Development

~ As embryos grow, they develop and become less alike.

~ The differences come from genes that have changed over the course of evolution, due to mutations or changes in DNA.

~ Mutations at an early stage of development are often lethal.


~ Gregor Mendel preformed many experiments with garden peas.


~ Purebred organisms, meaning they have two identical alleles for a particular trait.

~ RR


~ Organisms which have two different alleles for a particular trait.



The genetic make up of an organism


The physical characteristics of an organism

Lamarck's Theory

1. Internal Vital Force

- Organisms and their organs have a natural tendency to continuously increase in size generation after generation, making them larger and more complex.

2. A Desire To Change

- Organisms constantly strive to improve themselves and become more advanced.

3. Law of Use and Disuse

- The effort to improve causes the most used body structures to develop, while unused structures waste away.

4. Inheritance of Acquired Characteristics

- Once an organism is modified, the modification can be inherited by the organisms offspring.

Charles Lyell & Darwin

Charles Lyell demonstrated that the Earth was very old and had changed over time which was important to Darwin as it would have taken millions of years for species to have evolved from a common ancestor.

Thomas Malthus & Darwin

~ Observed that babies were born at a faster rate than people were dying.

~ Reasoned that sooner or later there wouldn't be enough living space or food.

~ The only conditions that would prevent endless growth of human population were famine, war, disease.

~ Observed in the Malthusian Doctrine.

August Weismann

~ Disproved Lamarck's Theory.

~ Did this by cutting the tails of mice for 22 generations but kept getting mice with long tails.

Reproductive Isolation

~ The main agent for the formation of new species or speciation

~ Pre-mating Factors:

1. Geographical Barriers: Mountains, Rivers

2. Habitat Preference: Deer Mouse & White Footed Mouse

3. Behavioural Differences

4. Mating Seasons

5.Body Structure or Size

~ Post-mating Factors:

1. Infertile Offspring

Mutation Vs. Adaptation

~ Adaptation is an inherited trait that increases an organisms chance of survival in a particular environment & is always an advantage.

~Mutation is a change in the DNA which is either a positive or negative

What Darwin Didn't Know

~ Darwin did not understand why there was so much variation within a population

~ He was unaware of mendel's work

~ The structure of DNA isn't established for another 80 years.

Results of Evolutionary Change

~ Divergence or Convergence

Divergence- Adaptive Radiation

~ Two species gradually becoming increasingly different

~ A variety of species develop from a single species

~ Ex. Darwin's Finches

Divergent Evolution: Artificial Selection

~ Can be spread up through artificially selection

~ Eg. Dogs which are bred to obtain certain physical characteristics

Convergent Evolution

~ The emergence of biological structures or species that exhibit similar functions and appearance due to similar habitats.

~ Not a common ancestor

~ Ex. Hummingbirds and Moths

Parallel Evolution

~ When two species evolve independently of each other, maintaining the small level of similarity.

~ Eg. Placentals and Marsupials

Biological Coevolution

~ The evolutionary change of one species is triggered by interaction with another.

~ Eg. Flowers

Stabilizing Selection

~ Individuals with the average form of a trait have the highest fitness and individuals at both ends of the extreme form are weeded out

~ Infant Mortality

Hardy Weinberg Theorem

~ States that both allele and genotype frequencies in a population remain constant if they are in equilibrium

~ Conditions for Equilibrium:

1. Mating is Random

2. No Mutations are arising

3. No Gene Flow

4. No Natural Selection

5.Population Size is large


~ The change that occurs if any of the conditions of the Hardy- Weinberg theorem are not met.

Gene Flow

~ Occurs when breeding members of a population leave a population or new members enter and new alleles are introduced or taken from to the population

~ Continual gene flow between populations decrease the difference in allele frequencies.

Genetic Drift

~ Chance events that cause the allele frequency to change

~ Bottleneck effect is an example, where a catastrophic event causes a decrease in organisms and may also decrease the variation in the population, thus changing the allele frequencies.

Directional Selection

~ Individuals with an extreme form of the variation have a greater fitness

~ Darwin's Finches

Disruptive Selection

~ Either extreme of variation of a trait have a higher fitness than individuals with the average form of the trait.

~ Rare in nature but suggests why speciation can occur without population segregation.

Artificial Selection

A process of breeding where a breeder chooses to mate only species that have desirable traits.

Natural Selection

A process where only organisms that are best adapted to their environment tend to survive and pass their genes to their offspring

Survival Of The Fittest

It is the term for a natural process that results in the evolution of the organisms that are best adapted to the environment.


A group of interbreeding organisms of one species that live in the same place at the same time.

Gene Pool

The number of genes in every individual in an interbreeding population.

Relative Frequency

Describes the ratio of the number of times an event occurs to the number of occasions on which it occurs.


The evolutionary process where a new biological species arises


Describes the specific role, function, and area that an organism occupies in an ecosystem.


~ Slow consistent change over time leading to a new species.

~ Darwin's theory of natural selection follows this model.


A state of balance between all acting influences, creating stability.

Mass Extinction

The extinction of one or more species in a short period of time, usually due to a catastrophic event such as a natural disaster or abrupt change in the environment.

Punctuated Equilibrium

~ Long, periods of no change, interrupted by short and rapid periods of sudden change and quick change.

~ Mechanisms other than natural selection cause bursts of change such as environmental disasters

~ The fossil record and the gaps strongly support this model for some species


~ A permanent (and inheritable) change in the nucleotide sequence in a gene or chromosome of an organism.