population
A group of organisms belonging to the same species in a specific location and at a specific time.
species
Organisms sharing similar traits and that can reproduce fertile offspring with each other.
gene pool
Sum of all the genes in the population.
variation
Difference in traits between the population.
gene
Determines an organism’s characteristics.
allele
An alternate form of a gene.
frequency
The rate at which something occurs.
gene frequency
How often a certain genes appears within a population.
selection pressure
Something which makes it easier to survive in an environment compared to others.
survival of the fittest
Those whom are best suited to the environment will survive and pass down their favourable trait to their offspring.
microevolution
Small changes in traits to a species over a long period of time.
macroevolution
Changes in traits in a species result in the development of an entirely new species over a long period of time.
natural selection
Organisms with higher fitness will live and come to produce more offspring, which therefore allows for their favourable gene to pass down.
fitness
The ability to survive and reproduce.
mutation
The source for variation in genes and producing new alleles, in which errors within DNA create different genotypes and phenotypes depending on the current environment.
random genetic drift
Chance of variation in traits in a small, isolated sample of a population.
founder effect
Subcategory of Genetic Drift in which a small sample leaves their population and migrates elsewhere, becoming separated with their original population.
bottleneck effect
Subcategory of Genetic Drift in which only a small sample of a population survives a natural disaster, restricting the gene pool to that small sample.
gene flow
Migration of a sample from one population to another. Can either be emigration in which the sample leaves and immigration in which the sample enters.
barriers to gene flow
Stops Gene Flow from occurring. Can be geographical barriers or socio-cultural barriers.
sexual selection
Mating in which the partner is specifically selected for reasons such as traits possessed. Examples of this include Male Competition and Female choice.
artificial selection
In which humans breed animals in which possess desirable traits to increase the frequency of that gene in the gene pool. Also known as selective breeding and commonly occurs with crops, dog breeds, and livestock.
biotic
Changes due to living organisms.
abiotic
Changes due to a non-living environment.
speciation
Evolutionary process in which new species are created. Can only occur if a barrier to gene flow is present.
isolation
A barrier that folds a population in two. A step in speciation in which separates two halves of a population from interacting and therefore reproducing.
temporal barriers
Barriers that stop organisms from reproducing with one another due to a difference in breeding seasons.
behavioural barriers
Barriers that stop organisms from reproducing from one another due to differences in behaviour.
mechanical barriers
Barriers that stop organism from reproducing with one another due to physical barriers that prohibit the combining of gametes.
chemical barriers
Barriers that stop organism from reproducing with one another due to chemical barriers that prohibit the combining of gametes.
geographical barriers
Organisms that are physically separated by land formations, prohibiting them from reproducing with one another.
selection
The step in Speciation in which involves Natural Selection, creating a change in gene frequencies in a gene pool.
allopatric
A type of Speciation. The population splits into halves due to geographical isolation.
peripatric
A type of Speciation in which a smaller sample breaks off from the population.
parapatric
A type of Speciation, where partial separation in the environment causes diverging populations. These organisms can only breed with other organisms close by.
sympatric
In which species occupy the same location but utilise different food sources.
phylogeny
Study of evolutionary relationships of species.
common ancestor
Ancestor shared by two or more species.
fossil formation
Evidence of Evolution, in which evidence of previous species are preserved within soil and rock. It also follows a process of burial, deep burial, and over a long period of time, exposure.
fossil record
Evidence of Evolution and is used to note various changes in traits of an organism over time. This helps find transitional forms (the transitional form between one species and another).
homologous structures
Structures of different species that have the same structure but serve a different function.
analogous structures
Structures of different species that have different structures on the inside but strive to achieve the same function.
vestigial structures
Structures that may have once served a purpose for a past ancestor, yet no longer do so for the current species. Some examples of this in humans is ear muscles, body hair, and wisdom teeth.
embryology
Study in which observes how species will have a similar embryotic stage to other various species.
comparative DNA sequence
In which comparing genetic code (amino acids) reveals how species are closely/sparsely related depending on the similar of their sequences.
law of superposition
The further down you go in the lithosphere, the older the rock will be. We can apply this law to fossil dating.
index fossil
Found fossil in which matches up with a specific time period.
stratigraphy
Study of sedimentary layers and rocks.
radiocarbon dating
Determining the age of a fossil by measuring the amount of carbon-14 it has. It is a form of absolute dating.