almost done lol

Microevolution

Changes in the frequency of an allele within a single population

Macroevolution

Evolutionary forces that transcend the boundaries of a single species

Population

A group of individuals of the same species living in the same geographic area at the same time

Formula for genotype frequency

Number of individuals with genotype / number of total individuals

Formula for allele frequency

Number of one specific allele / number of total allele

Null model

Simplified scenario showing what we’d expect to happen if nothing is affecting the system

Hardy-Weinberg Equilibrium

In the absence of evolutionary processes, the allele frequencies in a large population do not change from generation to generation

Outcome 1 (HW Equilbrium)

1. Allele frequencies are not changing

2. The gene is at equilibrium

3. The gene is not evolving

Outcome 2 (HW Equilbrium)

1. Allele frequencies are changing

2. The gene is in disequilibrium

3. The gene is evolving

Break assumptions of hardy weinberg

1. Natural selection

2. Large population

3. Migration

4. No new mutations

5. Random mating

Natural selection

Some genotypes are at a disadvantage, and do not survive or contribute to the gene pool equally

Directional selection

One extreme phenotype provides a fitness benefit, so the average phenotype in the population moves toward that extreme

Stabilizing Selection

Phenotypes in the middle of the range provide a fitness benefit, so extreme phenotypes become less common

Disruptive selection

Phenotypes of both extremes provide a fitness benefit, so intermediate phenotypes become less common

Balancing selection

No single phenotype is favoured at all times, so a diversity of phenotypes are always maintained in the population

Environmental variation

Variations in the environment favour different phenotypes at different times or places

Frequency- dependent selection

Rare alleles provide a fitness benefit

Heterozygote advantage

Have higher fitness than homozygotes

Genetic drift

The frequency of alleles can be altered by random events affecting survival or reproduction. Is greater in small population as any one random event affects a larger % of population

Fixation

where a single allele becomes the only one in the population

Founder effect

When a new population is founded, allele frequencies will change based on the random immigration of individuals to form the new population

Genetic bottleneck

Sharp reduction in population size randomly removes individuals from the population, and the remaining individuals have a different allele frequencies

Gene flow

Some alleles are added or lost from the gene pool due to movement of organisms or alleles. With enough allele frequencies will become identical

Mutation

Allele frequencies may be altered by new alleles generated by mutations in individuals. Happen when the DNA of an organism is permanently changed. Happens randomly.

Adaptive evolution

Evolution that results in a better fit between individuals and their environments

Non-adaptive evolution

Evolution that has random effects on fitness. Individuals are not better adapted

Speciation

The evolution of two or more distinct species from a single ancestral species

Allopatric speciation

Species is split into two geographical groups, divided by a barrier. The two groups diverge over time to become two species

Sympatric speciation

Species diverges into two groups while occupying the same geographical area

Vicariance

A population is split into smaller, isolated population by a geographic barrier

Allopolyploid

A polyploid formed by hybridization between two species

Autopolyploid

A polyploid formed by doubling chromosomes from the same species

Speciation by genome duplication

• An error in meiosis produce a diploid, and offspring with a duplicated genome (2n => 4n)

• Isolation occur because tetraploid (4n) and diploid (2n) crosses produce infertile triploid offspring (2n + n = 3n)

Adaptive radiation

Rapid evolutionary diversification in a single lineage, producing many descendant species with a wide range of adaptive forms

Ecological opportunity

A new habitat or resources; reduced competition or predation

Innovation of new trait

A significant new morphological, physiological or behaviour trait arises

Evolution of dentition

Allowed for dietary diversification and specialization in different groups

Rise of flowering plants

Provided significant sources of food and habitat for mammals

Extinction of the dinosaurs

Reduced predation pressure on mammals and opened niches for new mammals species

Bipdealism

Freed up the arms, allowing for efficient tool use, gathering and carrying food, and using hands to communicate. Ardipithecus first hominin to do this

Homo genus and big brains

Speculated this could aid social interaction, tool use, language, responding to changing environments, and allowing for conceptual complexity. Has increased 3 fold over 2.5 million years

Tool usage

Helped collect food and fuel, build shelters, cook food, and extract other resources more efficiently. Only less than 1% present in animals

Reduced jaw muscles

Cooking food before eating it makes food softer, and it is easier to extract nutrients. Became smaller attachment area on the skull.

Language evolved in Homo genus

Convey information about danger, food and other resources and coordinate their communities.

Modern humans

Homo sapiens lived alongside and interbred with other Homo species like the Neanderthals and the Denisovans

Skin colour ad balancing reaction

Increased skin pigments blocks more UV radiation

Folate => needed for healthy cells and fetal development but degraded by UV ration

Vitamin D => Needed for healthy bones but is synthesized in the skin by UV radiation

Ecology

The scientific study of interactions between organism and their environment

Biotic environment

Living things an organism interacts with

Abiotic

Non-living things an organism interacts with

Organismal ecology

A field studying the morphological, physiological, and behavioral adaptations that have evolved in response to ecological selection pressures

Population ecology

Studies groups of individuals of the same species and the factors affecting their population size and distribution

Community ecology

Studies all population of species in an area and how species interact with each other

Ecosystem ecology

Studies all biological communities in an area and their abiotic environment

Landscape ecology

Studies how multiple ecosystems interact by exchanging energy, nutrients and organism

Global ecology

Studies the relationships among organisms and their environments

Behavioural ecology

Studies behavioural adaptations that have evolved in response to ecological selection pressures

Proximate cause

How the behaviour works. The biological mechanism that lead to the behaviour

Ultimate cause

Why the behaviour exists. The evolutionary benefit to survival or reproduction

Innate behaviour

Behaviour inherited genetically does not have to be learned, and is typical of a species

Learned behaviour

An enduring change in an individuals behaviour resulting from a specific experience

Optimal foraging

Maximizes the amount of usable energy they take in, given the costs of finding an ingesting their food and the risk of being eaten while they’re at it

Trap-lining

Individuals visit food sources in a regular, repeatable sequence

Root foraging

Plants increase root growth in nutrient-rich patches of soil

Decentralized

Slime mold colonies explore many paths to food can recreate efficient

Evolutionary game theory

A mathematical modeling approach to predicting the outcome of natural selection on behaviours when multiple “players" are interacting

Producers vs Scroungers

Some individuals find food, others watch and steal it

Group vs solo foraging

With other individuals may increase access and abundance of food, but increases competition

Prey preferences

Choosing different prey than other individuals reduces direct competition for that food

Sexual selection

A type of natural selection that favours individuals with traits that increase their ability to obtain mates, or choose good mates

How many potential mates are available

If mates are rare, individuals may be less choosy

How much competition is there for access to mates

High competition can lead to intense sexual selection

How much parental care can the mates contribute

When one sex contributes substantial care, the other sex may be choosier

What quantity and quality of resources are available

Mating success may be tied to who controls valuable resources

Polygyny

One male mates with two or more females (more sexual dimorphism)

Polyandry

One female mates with two or more mates (more sexual dimorphism)

Promiscuity

Males and females each have two or more mates

Habitat selection

The rules used by organisms to choose among patches of habitats that differ in things like food availability or predation risks

Density-Dependent

Organisms make different choice of habitat depending on how many individuals are present

Habitat matching

Organisms select habitats whose environmental conditions match their phenotypes

Microhabitat selection

Organisms choose specific, small scale environments within a larger habitat that best suits their needs

Dispersal

The movement of individuals from their place or origin to a new location

Active Dispersal

Organisms move location by their own power or abilities. Involves behavioural decision making

Passive Dispersal

Organism rely on external factors like wind or water to move them

Migration

A seasonal long distance movement of large number of organism form one geographic location or habitat to another

Piloting

A type of navigation where animals use familiar landmarks to find their way

Compass orientation

A type of navigation where movement occurs in a specific direction

True navigation

A type of navigation where an animal can reach a specific point on the Earth’s surface

Communication

Any process in which a signal from on individual modifies the behaviour of another individual

Auditory

Vocalization or vibrations

Visual

Body colour, posture, or movement

Chemical

Pheromones or odors

Tactile

Touch or physical contact

Other

Electricity and temperature

Honest signals

Signals accurately convey information. Natural selection most of the time favours this.

Deceptive signals

Signals mislead the receiver to the benefit of the sender

False calls

Calls of predatory animals to scare off rivals and take their food. This takes advantage of honest calls warning of danger

False chemicals

Release pheromones to lure prey

Altruism

Behaviour that has a fitness cost to the individual and a fitness benefit to the recipient

Cooperation

Interactions between individuals where both parties benefit from the interaction

Mutalism

A form of cooperation between different species