Biology, - 03

Mutation is the source of…

All new genetic variation. Increase genetic diversity

Codon

Sequence of three bases ; codes for an entire amino acid. Linked together make proteins

Three main ways of classifying mutations

silent, point, frame-shift

Example of genetic mutations

Original ; CAGCAUGGU

Single nucelotide polymorphism ; CA(A)CAUGGU

Insertion changes the whole thing (frameshift) ; CAG(A)CAUGGU

Deletion ; CACAUGGU

Small scale

Changes in DNA sequence; point mutation, single nucelotide polymorphism, insertion/deletions

Large scale

Changes in chromosome structure; deletion, duplication, inversion, fusion

Genetic Drift

any change in allele frequencies in a population due to chance (sampling error); it causes allele frequencies to drift up and down randomly over time

Smaller populations…

More prevalence of genetic drift

Overtime genetic drift can lead to..

random loss or fixation of alleles

Genetic bottle neck

Large population decreases a random sample of the individuals with random alleles survives; alters allele proportions

Founder effect

small number of individuals leave a population, random sample of individuals with random alleles survive and start a new population; alters allele proportions

Inbreeding depression

the delcine in average fitness that takes place when homozygosity increases and heterozygosity decreases in a population

inbreeding depression results from two processes

many ressecive alleles represent loss of function mutations

many genes (esppecially those involved in fighting of diseases) are under intense selection for heterozygote advantage

Extinction vortex

small population = inbreeding and genetic drift = loss of genetic variability = decrease in adaptability and fitness = increase in mortality and decrease

gene flow

introduce new genes in a population, increases similarity of the populations may prevent specitation

Mean

adding all observed numbers and dividing by the total of number of observatipons

median

the point in the dataset with half oteh values above and half below

range

difference between highest and lowest observation

quartiles

divide data into four equal parts (25%)

Directional selection

Phenotype changes in one direction. Purifying selection. Reduces genetic diversity of populations

Stabilizing selection

Mean value of trait does not change. Reduce genetic variation and extremes

Disruptive selection

Can cause speciation can form new species

Balancing selection

Maintains variation in traits. Variable dependent frequency dependent

Bateman trivers

Fundamental asymmetry of sex has two consequences

Female fitness is limited by the ability to gain resources needed to produce more eggs and healthier offspring

Male fitness is limited by the number of females he can mate with

Intrasexual selection

Individuals of same sex competing for mate

Intersexual selection

Choice in different sex mate

Conservation

Any distinct population segment of any species which interbreeds when mature

Definition of species

Evolutionary independent population or group of populations

Species concepts

Identifying or recognizing species based on description

Morphospcies concept

Individual species differ in morphological features

Reflect barrier to gene flow

Cryptic spcies

Group of related organisms who look similar despite important differences are lumped into too few species

Biological species concept

Groups of actually or potentially interbreeding natural populations which are reproductively isolated from other groups.

Populations who are reproductively isolated don’t mate with each other and don’t produce fertile offspring therefore are separate species

Ecological species concept

Based on shared ecology such as habitat or other resource use.

Phylogenetic species concept

uniquely identified as group and share common ancestor. Evolutionary history, monophyletic groups, and clades or lineages

To spectate populations undergo events…

Population of one species separate

Accumulate diffferences

Reproduction isolation may become permentang under correct circumstances

New species is formed

Reproductive isolating mechanisms

Prevent genetic exchange between species

Prezygotic isolating mechanisms

Don’t let the zygote form

Prezygote - Allopatric

Separated by different locations

Sympatric

Same location but separate

Temporal isolation

Different breeding seasons

Behavioral isolation

courtship used to advertise assests. If small differences may prevent breeding

Mechanical isolation

Structural differences that prevent mating between related species such as genital morphology

Triploid trout

Do not invest in reproduction put energy toward growth and cannot reproduce

Postzygote isolating mechanisms

Prevent proper functions of zygotes once formed

Failing to mature

Hybrid offspring lower survival ship

Maturing into infertile adults

Organismal ecology

Physiological. Behavior and innate responses or learned

Population ecology

Individuals of population in same area study

Community ecology

Population of different species, interactions

Ecosystem ecology

All biotic and abiotic components shared area

Proximate

How. Mechanisms that produce behavior, environmental stimuli. How is a behavior triggered?

Ultimate

Why. Significant of behavior, how behavior increases fitness. Why does this animal behavior?

Flexibility of behaviors

Infant behaviors are not flexible.

Learned behaviors have more flexibility

Cost benefit analysis

Link between fitness and behavior

C/B measured in terms of impact of fitness

Not always conscious

Major behavioral questions

What should I EAT

who should o mate with

Where should I live

How should I communicate

When should I cooperate

Migration

Long distance movement of a population associated with a change of seasons

Piloting

Use of familiar landmarks

Compass orenitation

Movement orientated in a specific direction

True navigation

Ability to locate a specific place on earths surface

Accurate signal

Species specific signals to each other for courtships

Deceptive signals

Utilizing signals to deceive and eat and or kill another animal

Deceit only works when

It is rare

Hamilton rule

BR > C

B

Fitness benefit to beneficiary

R

Coefficient of relatedness

C

Fitness cost to the actor

Density dependent population

Natural selection in which the fitness of a trait depends on population density.

When a population becomes crowded, individuals that compete more effectively for limited food and space have higher reproductive success

Standard Deviation

measures how spread out data values are from the mean.

Standard Error

Measures how precisely a sample mean estimates the population mean.

Reciporcial Altrusism

An individual helps another at a cost to itself, with the expectation that the favor may be returned in the future.

Eusociality

Involuntary altruistic behavior, ex. bees, naked mole rat (sterile workers)

handicap hypothesis

females assess the quality of a male by his ability to survive despite having a trait that could potentially be determental to his health

Rovers

move after feeding in a particuklar location

sitters

stay in one location; high heritability

Direct Fitness

Derived from an individuals own offspring

Indirect fitness

derived from helping relatives produce more offspring than they could produce on their own

Kin selection

natural selection that benefits relatives and increases indirect fitness

biogeography

The study of how organisms are distuted geographically

No organism can live everywhere

Wallace line

Actual separation line. Separate species with Asian and Australian affinities

Tsetse fly

Carry trypanosomias which is fatal to cattle and sometimes human and may limit cow distribution in Africa

Biotic and abiotic factors can act together to,…

Limit the distribution of organisms

Factors that determine species range

Abiotic factors; temperature, rainfall, geographic boundaries, historical process.

Biotic factor; competition, predation, food associations

Population

Group of individuals from same species living in same area at same time

Population ecology

Study of how and why number of individuals in a population changes over time

Clumped

Concentrate resources

random

High dispersal

Uniform

Negative interactions the population is spread out

Population density

Number of individuals per unit area often varies throughout range

Dispersal

Movement of an individual from place of birth to it lives and breeds as an adult

Meta population

Population of populations connected by migration

BIDE model

Bath tub model.

Density dependent

BIDE change as a function of density

Density independent

Bide may nchange but not as a function of population density. Eg natural disasters

Effects of carrying capacity

The population grows more slowly as N nears K

Competitors share…

K

Symmetric

Resource use does not overlap niche differentiation occurs

Asymmetric

Too close and one species is a better competitor

Population cycle

Foundations in size

Organisms with high fecundity

Grow quickly

Reach sexual maturity at young age

Produce many small eggs

Organisms with high survival ship tend to

Grow slowly invest in traits that reduce damage from enemies and increase competitive ability

Survivor ship curves

Type I - die at old age

Type II - even

Type III - low at young age