Evolution

A change that times place in a group of organisms over time, usually in gene frequency.

• Any consistent difference in fitness (reproductive success) among phenotypically different classes of biological entities.
• - 4 levels -> genetic, individual, population, species

species are static and created by a higher source; against Darwinian science

Lyell; idea that processes that created the earth are still happening today

punctuated equilibrium; attributed new species in area to very dramatic event; assumed supernatural (like the flood)

thought life was wiped off the face of the earth and brought back more complex than before

Study of nature to get closer to the creator

theory that if something complex was found (like a watch) someone had to have made it and put it there

• Lamarck; theory that species became more complex because they want to
• 1. environmental changes invoke changes
• 2. changes in activity caused by needs
• 3. changes in habitat result in more/less use of parts and bigger/smaller parts
• 4. all changes are heritable

small changes with in a species

causes big changes above the species level

• 1. species can and do change overtime (NS)
• 2. Man's place in the natural world
• 3. helped to form scientific community separate from religion and politics

the fitness of gene measured by its effect on survival and reproduction of the organism and its genes borne by the individual's relatives

individual favoring survival of those closely related

• competition with in species -> males vs. males, females vs. females
• - big secondary characteristics

• convincing opposite to mate
• - bright colors, plumage...

• 1. gene flow
• 2. genetic drift

• trait that is used for something and useful for something else later if that environment changes
• ex. penguins "fly" with wings under water

• few individuals are taken from large founder population and are isolated until they produce their own population and look different over time
• - why species look different on islands

• - Mayr
• species where interbreeding is possible but reproductive isolation occurs between other species
• -exception - asexual, fossils, bacteria

• genetically based, heritable change in a population or species
• - not individuals

branching in tree, search for common ancestor

• hierarchy
• - KPCOGS
• Lineauus latin names

• different features of organisms used to show relatedness
• -morphological, genetic, embryology, physiology, behavior, biochemical

• an ancestral state
• ex. tail, 4 limbs

• a derived character state
• ex. increased brain size

goal of phylogeny; a set of species derived from a single, common ancestor

shared, derived traits; most helpful in determining phylogeny

• 1. uniquely derived character states
• 2. ancestral character states
• 3. homoplasious character states

trait developed from convergent evolution

developing the same traits at the same time as other species after they split off

multiple changes that occur with in one species/lineage

as time passes, you get mutations and changes in the structures of genes

origination of branches

• changes that happen with in a lineage
• -lumpers - include more individuals in few groups
• - splitters - more groups in split

• same trait developed from common ancestor
• ex. forelimps

• characteristics that are not used but are ancestral
• ex. appendix, wings in birds that don't fly

• evolution of similar features independently in different evolutionary lineages
• - by different developmental pathways
• ex. vertebrate vs. octopus eye

• where species are located
• ex. marsupials only in sa and australia

• forms from ancestral states that still remain and haven't changed
• ex. pelvis in snakes

• no common ancestor; traits that show up not because of common ancestor
• ex. color, loss of trait, beak size
• - leads to analogous structures -> bird and bat wings

harmless mimics something poisonous

• two toxic species that look alike
• mimicry rings - protection for all toxic species that look alike from predators

• have similar conditions that involve similar developmental pathways
• ex. maxillped in crustaceans

• resemble ancestor of another species
• ex. frogs that have regained the character state of having teeth

share the same structure but derived by different developmental pathways

same structure derived by same developmental pathways

species evolve piecemeal; pieces of species change overtime and some stay stagnant

• -body temp regulated inside (mammals)
• -body temp regulated outside (reptiles, fish)

quick jumps in evolution with short-terms of stability

continuous, long-term stability; things change gradually with time

• bodies of organisms consist of modules, compartmentalization
• ex. teeth in reptiles all look the same

• evolutional change in the timing or rate of developing events
• -localized or large scale
• ex. horns that keep growing (localized)

• maintaining juvenile characteristics through life
• ex. salamanders

• developing exaggerated adult features and maturity
• ex. human brain

• differential growth in different parts of an organism
• y=bxa
• - exaggerated characteristics can result

change in development time

change in rate of development

• change of where genes are expressed in the body
• ex. light emitting organs
• ex. photosynthetic stems

• rapid, divergent evolution of numerous related lineage
• -not moving towards trend/direction
• - see this at edge of species range/colony

• last universal common ancestor
• #1 on tree
• ex. all living things use L a.a. isomers

replicating conditions of early earth to try to form organic from inorganic substances

stable, simple, could have been precursor to RNA

• Quaternary:
• 1. Holocene
• 2. Pleistocene
• Tertiary:
• 1. Pliocene
• 2. Miocene
• 3. Oligocene
• 4. Eocene
• 5. Paleocene

• 1. Cretaceous
• 2. Jurassic
• 3. Triassic

• 1. Permian
• 2. Carboniferous
• 3. Devonian
• 4. Silurian
• 5. Ordovician
• 6. Cambrian

- precambrian

• structure derived from an organism within another
• ex. chloroplasts, mitochondria

average rate of extinctions overtime, mass extinctions are spikes in background rates

• separation/ barrier of population; speciation occurs because of separation or geological barrier
• -null hypothesis
• -split occurs AFTER separation of species

• when a population moves from an area where they do well to where they may not do so well (ex. seeds)
• - dispersal model -> split occurs BEFORE separation of species

• island species
• - flying animals are more capable of dispersal to islands
• - human introduced species do well on islands
• - species are related to mainland species
• -endemic species on islands only found there

group arises within a geographical region

group arises from somewhere else (dispersal)

• tracking lineages of genes based on geographical distribution
• - can be used when no fossil record present

• 1. Multiregional - archiac humans from africa, asia, eurp give rise, large diff between genes, alot of gene flow
• 2. Replacement - archaic humans moved out of africa and dispersed, small diff in genes

• similar in similar species
• ex. birds have similar beaks if they eat similar foods

• - linear relationship between the size and distance of the island from the mainland and the number of species on the island; bigger islands have more species
• far and small = smallest equilibrium
• large and near mainland = largest equilibrium (constant rate of species)

number of species you find in an area and how they are distributed

• - number of species
• - how species are distributed

• species rise and go extinct at the same time
• - just one fossil is found
• ex. soft bodied animals
• - usually excluded from species numbers

greater tendency to find species that are new to the fossil record, looks like there's more diversity now because it's easier to count them

S-E = R

• dependent - biotic factors - predation, competition
• independent - abiotic factors - weather, natural disasters

• species with high turnover rates, high origination rates, high rates of extinction
• - highly specialied
• - low or variable population size
• - low geographic range and dispersal ability

change in response to surroundings, change for the BETTER from previous form, increase in fitness

ability to survive and reproduce

species must evolve as fast as they can just to keep up with competitors and predators, to maintain the same level of fitness

all basic body types emerge during this

• H - habitat loss
• I - introduction of exotic species
• P - population (humans)
• O - Overexploitation

species that was thought to be extinct shows up again

take advantage of whatever resources they find

species that do better after a disturbance

• species that persist in a certain place while others go extinct elsewhere
• ex. species that live in deep ocean are unaffected by disturbance

• species can reproduce but still have larval form
• -heterochrony

-very prone to extinction bc rarely exposed to changes

• 1. microevolution - change w/in a species population
• 2. species selection - differential survival of species during "normal" times
• 3. shaping of biota - dramatic change in higher taxa following mass extinctions

ecological role that individual holds

entire range of resources species can use, full range of environmental conditions

narrowed niche than fundamental, most highly adapted area

• extinction of a species because of competition, taking over a niche by competition
• - much less common

• species takes over a niche of species that has gone extinct
• - much more common

• trait that allows colonization of new niche, diversification
• - ex. lungs, wings, amniotes

• range of resources used by a group, set of ecological niches
• ex. herbivorous insects

• - located in the same place, interbreeding
• - barrier separates them
• - mostly separate but have a hybrid zone in between

• a population of species that can interbreed but separated by a large distance
• - speciation in progress

a gradual change in allele frequency over a geographic distance

• increase in latitude brings increase in body size
• ex. bears

• longer limbs as you move towards the equator
• ex. hares, humans

• darker coloration in more humid climates
• ex. skin color in humans

mosaic pattern of character distribution

• species that live together look different, where they live apart they look similar
• - niche partitioning

• change in genes among population or movement of gametes
• -discrete population = islands
• - continuous population = isolation by distance

• 1. gene flow - homogenizes populations
• 2. NS - adaptive
• 3. genetic drift
• 4. mutation

• random change in allele frequency
• - not because of fitness
• - based on chance
• - Kimura
• - most important in small populations
• - null hypothesis of change

• those that survive and found in next generation
• ex. snails and cows --> starting frequency is probability of becoming fixed and lost
• allele is 20% -> 80% chance of loss, 20% chance of fixation

process of going back to a common ancestor through gene lineages

alleles can be fixed or lost in populations

• WANT hetero. to be high in population to show diversity and variability
• -more homozygous means low variability

deals with number of individuals who are actually getting to mate and reproduce

much larger than effective size, total number of pop.

population is drastically decreased and leads to change in allele frequency

small proportions of noncoding DNA are affected by NS

• when species trade a benefit for a possible negative
• ex. frogs who croak loader and longer get more mates but are also recognized by more predators

attributing purpose to something

• average, percapita rate of increase in numbers
• - proportion of survival for offspring

type of NS, differences in reproductive rates

base pairs get switched on chromosome and changes outcome of phenotype

helping the group at a cost to oneself

• 1. complexity
• 2. design
• 3. experiments
• 4. comparative method

• evolutionary stable strategy
• - type of behavior that can not be replaced by alternative
• ex. hawk type of species

• rb> c
• r= relatedness
• b = benefit
• c = cost
• C must be less than the relatedness x benefit to be beneficial to organism