BIO 1

• Cellular organization
• Metabolism
• Homeostasis
• Reproduction
• Growth
• Heredity

One or more cells

Large molecules that contain carbon as a major component

Prokaryotic and eukaryotic

When a cell obtains and uses energy

• Building molecules
• Moving of cell structures
• Growing of cells
• Production of new cells

Maintain stable internal conditions within and among cells

Produce offspring similar to parents, due to passing of genes from parent to offspring

Increase in size due to increase in number of cells and increase in size of each cell after it is formed

Posses genetic information in the form of DNA molecules

Deoxyribonucleic acid

• Descent w/modification
• Species arise from a series of ancestors, lead back to a common one
• Characteristics of new species differ from its ancestors and other descendants

• Process where individuals that have certain heritable characteristics survive and reproduce at higher rates
• Can increase adaptation of the members of a population to their environment

• Individuals in a population differ in their traits, which are heritable
• Members of a population produce more offspring than can survive in environment
• Competition for limited resources occurs among members of population
• Individuals w/traits best suited to local environment have higher probability to obtain resources
• Successful competitors survive and reproduce at higher rate
• Higher proportion of individuals in next generation will have their traits

At the unequal reproductive success of individuals

When the population adapts to its environment

Plasticity of characteristics

Smaller fish pass through mesh of gill nets and survive to reproduce, pass on genes for smaller size to their offspring

Herds of elephants have a high proportion of members lacking tusks. Due to poaching, absence of tusks probably due to specific allele and not plasticity in tusk presence/size

Brings about rapid change in population traits

Population traits shifted at rapid rates resulting in younger age/small size of reproduction

Genetic changes

Phenotypic plasticity

No, the rate of change varies over time and place

• Movement to new environment
• Shifts within environment

Global warming, human harvesting

Continental drift, cold climates of ice age

May not be as well adapted

• Only inheritable traits can pass from one generation to the next
• Acquired characteristics aren't inherited
• Most traits don't possess a natural selective value
• The favorable/unfavorable value of a trait depends on environment in which it occurs
• Adaptive value of trait can change if environment changes

• Populations w/distinctive traits arise from ancestral populations lacking those traits
• Over time different and distinctive populations have come and gone

• Humans drive natural selection and population evolution
• Evolution in natural populations

• Harvested populations
• Insects to pesticides
• Bacteria to antibiotics

• Plant population adaptation to extreme soils (population adapts to a specific type of soil, produces endemics)
• Animal population adaptation to extreme conditions

Species which is unique to a place

The preserved traces of extinct organisms

Trace the origin of a group of organisms and the examination of changes that occur over time

Change of life on earth over history of life

Least complex

Contain more complex structures

Coincides w/expected evolutionary result of increase in complexity of living organisms over time

• Characteristics shared by a group of organisms which had a common ancestor
• Basic similarity present but modification in structure reflect altered functions in the various descendants

The theme of descent w/modification

Structural and molecular homology

Structure has been modified for a variety of functions

• The limbs of vertebrates, especially the forelimbs
• Terrestrial vertebrates all have the same basic forelimb bones

Shared molecular structures of genetic material

The common ancestor of all living organisms

The triplet of nucleotide sequences in DNA which code for the amino acids in a protein

• Some genes are universally shared, retain similar functional properties in all types of cells
• Some genes have similar molecular structure but different functional properties in different types of organisms

Geographic distribution of species

• Organisms move due to their own actions and due to movements of the continents
• The observed distributions of current and extinct species matched the expected distribution based on evolutionary theory

Species of large flightless birds found in South America, Africa, Australia and New Zealand. These birds are closely related even if they were found on different continents

A group of individuals of the same species that live in an area and interbreed and produce fertile offspring

Changes within a population

Individuals in a population

The differential survive and reproduction of its members produces changes in population

• Change within a population/species from generation to generation
• Change in allele gene frequencies in population
• Adaptation to an environmental factor

Changes of sufficient magnitude to produce new species

Observable form of trait in an organism

• Pair of alleles for specific gene present in an individual
• Formed of pairs of alleles

Each parent

• A gene determines a trait
• Alternate alleles of gene produce different forms of trait

• Gene: codes for the trait of flower color
• Alleles: (P) - purple color, (p) - white color

Study of the properties of genes in populations

Each allele of a gene occurs at a certain frequency in the population

• Gene: detoxifying
• Non-resistant allele: 0.98
• Resistance allele: 0.02
• These frequencies remained constant through many generations
• Non-resistance allele is unable to detoxify DDT
• Resistance allele can detoxify DDT

1 allele resent in the cell

2 alleles present in a cell

Allele frequencies in a population which isn't evolving are unchanging frequencies of alleles and genotypes remain constant from generation to generation

• A large populations w/random mating
• No input of new alleles

• The frequencies of the 3 genotypes formed from a gene w/2 alternate alleles
• When the allele frequencies are in equilibrium

p² + 2pq + q² = 1

Frequency of individuals w/2 copies of the more common allele

Frequency of individuals w/1 copy of each allele

Frequency of individuals w/2 of the less common allele

• Predicts no difference in the frequencies being measured
• No factors are acting on the population to change the frequencies of the alleles
• Some factor(s) are acting on the population to change the frequencies of the alleles

If from generation to generation the genotype and allele frequencies math those predicted by Hardy-Weinberg and remain unchanged

If after one or several generation, genotype frequencies don't match those predicted by the Hardy Weinberg equation

• Pre-DDT frequencies remained constant for many generations
• Presence of a DDT resistance gene was unknown because natural selection factor wasn't introduced to the population
• If environmental conditions didn't change, allele frequencies remained constant
• DDT was introduced when environment changed, natural selection acted on individuals of population
• Fittest individuals survived and reproduced (those w/resistance gene)
• Hardy-Weinberg equilibrium was broken, gene frequencies changed
• Microevolution occurred in mosquito population

• Variation is produced in the population (mutation and sexual reproduction)
• Allele frequencies are altered (natural selection, genetic drift, gene flow)

• It's a change in the nucleotide sequence of the DNA
• In an existing allele, may produce a new type of allele of the gene
• The change in the nucleotide sequence may alter the way the trait is formed from that new allele of the gene

Mutation

In the potential germ cells (egg/sperm) to be passed to offspring and into the population

• Alleles that are neutral (not changing the phenotype)
• Alleles that are slightly/severely negative (producing a harmful phenotype)

• Yes, on rare occasions. Its phenotype makes the bearer better suited to the environment and enhances reproductive success
• Over time and in large populations, alleles can produce favorable traits in their bearers, these are ultimate sources of variation in a population

1 mutation in every 100,000 cell divisions

Very few mutations

• Produces unique combinations of alleles in each individual
• Formation of egg and sperm shuffles alleles of each parent into a unique set in the gamete
• Union of egg and sperm produces new combination of allele pairs

Gametes of individuals w/different genetic backgrounds

Mixing of alleles into new combinations in the individuals of a population

Genetic and phenotypic variation in the individuals of a population

Those individuals whose traits are best suited to the environment leave a higher proportion of offspring in the next generation

Which types of individuals are fittest, these are the individuals "selected"

Transfers alleles into/out of a population

Change in allele frequencies of the population

• Migrations of individuals between populations
• Movement of gametes

Frequencies of the receiving population may be changed

• Insecticide: organophosphate (not DDT) was used for 30 years
• In Europe, a mutation producing a resistance allele occurred in mosquitoes
• The resistance allele spread rapidly due to long distance migration of mosquitoes (wind)
• Each area became resistance, mosquitoes w/allele kept being blown to new areas
• Much of the world's mosquitoes became resistance after introduction of resistance allele

Random change in allele frequencies in a population

Chance events

In small populations where events affecting a few individuals may have a large effect on the population

• Few individuals are isolated from a larger population and establish a new population
• Type and frequency of alleles in new population are a subset of the source population, may differ depending on allele combination occurring in the founders
• Rare alleles and combinations of alleles may be present in new population

• A group of populations whose members are capable of interbreeding
• Offspring are vigorous and fertile (healthy surviving offspring)
• Reproductively isolated, can't produce fertile offspring w/individuals from different types of population (one kind of species can't reproduce w/another group)

Gene flow, this maintains their gene pool (individuals move from one population to another)

• Consists of all the alleles for genes in all individuals of the population
• The frequency of any combination of alleles depends on the frequency of each allele in the population

That allele is fixed in the gene pool, all individuals have 2 copies of that allele

Each individual may have any possible combination of these alleles

An effective way of understanding the existence of different types of species population in nature

• Successful interbreeding can exist between different types of populations
• Difficult to apply to populations which don't occur together
• Many types of organisms are asexual, reproductive isolation doesn't apply

There isn't a definite set of factors that maintain the identity of species in nature

• Reproductive isolating mechanisms
• Prezygotic isolating mechanisms
• Separated in space, fertile at different times, incompatible behaviors, structural differences (doesn't get to zygote stage)
• Postzygotic isolating mechanisms
• Genetic incompatibility of the gene sets of the parents
• Hybrids developing to some extent, but die as embyros/juveniles (no further development than zygote)
• Hybrid adults are weak, vigorous, and sterile

Factors preventing mating and fertilization (zygote --> fertilized egg, single cell, individual)

Factors interfering w/proper development and reproduction of the offspring

• The formation of new species
• 2 populations of a single species diverge
• Reproductive isolation forms w/each of the 2 new species
• Population gene flow is altered and slowed, interrupted

• Populations become geographically isolated
• Gene flow is restricted (cut off one species in population)
• Gene pool of each population receives new alleles from mutation events
• Genetic drift is small, isolated population may alter gene frequencies

Similarities decrease and reproductive barriers form

In populations that live in the same geographic area

• Gene flow is reduced between separating populations while their members remain in contact
• Reproductive barrier develops and separates the 2 populations

Polyploidy

• Accidents in gamete formation in offspring w/increased number of sets of chromosomes (2+ sets of chromosomes)
• Such offspring may be reproductively isolated from parental population

In plants, and sometimes animals

A subpopulation is enabled to utilize a resource or habitat not used by the parental population