(aka Embryophytes)

monophyletic group: all land plants come from a single common ancestor

synapomorphy: development of embryo protected by tissue of parent plant

chlorophylls a and b, use of starch as storage, cellulose in cell walls

monophyletic group of land plants and all green algae,

all groups that possess chlorophyll b

(aka Tracheophytes)

all possess fluid-conducting cells = tracheids

7 groups of the 10 land plants

Nonvascular land plants

mosses, liverworts, hornworts

lack tracheids

nonvascular plants

no filamentous stage, gametophyte flat

nonvascular plants

embedded archegonia(egg producing organ)

sporophyte grows basally (from the ground)

nonvascular plants

filamentous stage

sporophyte grows apically (from the tip)

vascular plants

club mosses and allies

microphylls in spirals, sporangia in leaf axils

common in moist woodland understory

comprised vast forests in coarboniferous period

horsetails whisk ferns, ferns

vascular plants

differentiation between main stem and side branches

gametophyte is multicellular, not photosynthetic

Cycads, Ginkgo, Gnetophytes, Conifers

Seed, Vascular plants

compound leaves

swimming sperm

seeds on modified leaves

Ginkgo

deciduous

fan-shaped leaves

swimming sperm

vessels in vascular tissues

opposite, simple leaves

Conifers

seeds in cones

needlelike or scalelike leaves

Seed, vascular plants

Flowering plants

endosperm

carpels

gametophytes much reduced

seeds within fruit

algal group, retain eggs in parent

flattened growth form like form of basal land plants (like liverworts)

algal group, retain eggs in parent

sister group of land plants:

plasmodesmata joining cells, growth is branching and apical, similar peoxisome contents, mechanics of mitosis, chloroplast structure

cuticle = waxy cover, retards water loss

stomata = regulate gas exchange

gametangia = enclosed gametes, prevent dessication

embryos = young plants contained in protective structure

pigments

spore walls = contains polymer to protect spores from desiccation and decay

assocation with fungus = nutrient uptake from soil

-life cycle includes both multicellular diploid stage and multicellular haploid stage

-gametes produced by mitosis of gametophytes (n)

-spores that develop into multicellular haploid organisms by meiosis of sporophyte (2n)

- trend in reduction of gametophyte generation in plant evolution

-transitions = fertilization and meiosis

Selective benefits: diploid stage buffered against deleterious mutations, big 2n nurtures small 1n

Plantae Chloroplast

-all are derived from primary endosymbiois of cyanobacteria

-bound by double membranes

-photosynthetic membranes are in stacks (grana)

-chlorophyll a, carotenoids, phycocyanin

evolved metabolic pathway for anthocyanidin pigments

-pigment absorbs UV and blue, protects from UV damage

single-celled, marine

chloroplasts are called cyanelles

-membranes are not in stacks

peptidoglycan layer under outer membrane

almost all are multicellular, marine

chloroplasts lack peptidoglycan

membranes not stacked

store special starch granules

Ex: sushi nori, agar

freshwater, marine, symbionts

single-celled, filaments, sheets

Ex: lichen

Plantae = primary chloroplasts

red algae = phycoerythrin

green plants = chlorophyll b

streptophytes= retention of egg in parent

charales and land plants = branched apical growth, plasmodesmata, peroxisomes, mitosis, chloroplast structure

Land plants = cuticle, embryo protected, multi sporophyte, thick walled spores,

all but liverworts= stomata

membranes starting to appear in stacks,

still requires peptidoglycan gene

stomata control water loss with gas exchange

waxy cuticle reduces desiccation

Land Plant Synapomorphies

all = protected embyos

all but liverworts = stomata

green sporophyte

Vascular plants = tracheids, true roots, independent sporohyte

Angio and Gymno = seeds

Horsetails

common in moist areas

gametophyte is small, sporophyte is big

swimming sperm with flagellation

common in moist areas

gametophyte small and photosynthetic

sporophyte is big

gametes lack flagella, but still swim

Vascular/Support systems

Xylem: lycophytes and all higher plants have true roots to move water/minerals from the soil up into the plant, dead and hollow cells, structural support

Phloem: tubes of dead cells, tracheids, carry products of photosynthesis from leaves to sinks with high energy demands

Double Fertilization:a diploid zygote, triploid endosperm(storage tissue for starch or lipids)

Flowers: wind pollinated, co-evolved with animal pollinators, showy to advertise nectar, petals=landing platform, UV absorbing patterns point to nectar

Fruit: swollen ovarian tissue surrounding seed

Monocot or Eudicot

seed sprouts = a single cotyledon (seed leaf)

grasses, grains, orchids, palms, lillies, sedges

seed sprouts with two cotyledons

legumes, beans, non-coniferous trees, nuts, citrus

cell walls contain chitin

bodies composed of microtubular hyphae (in mass = mycelium)

Absorptive Heterotrophy: hyphae secrete digestive enzymes and absorb nutrients

Reproduction: Asexually(1n) = mitosis and "identical" spores

Sexually (2n or n+n)= mating of dif strains, cytoplasm fusion, nuclei fusion, meiosis, diverse looking

reduced mitochondria, polar tube (how they infect)

very small, intracellular parasites

still retain flagellated zoospore (ONLY FUNGI with it)

infects skin, especially frogs

causes electrolyte imbalance=cardiac arrest

*has caused 90-120 amphibian extinctions since 1980

Zygomycota

most are microscopic, but sporangium

zygospore= lots of nuclei (karyogamy)

Ex: bread mold, digest cellulose for termites, pathogens of insects

Glomeromycota

-close symbiotic relationsip with plant roots

-use glucose from plant partner as energy source and conver it to substancest that can't go back to partner

-reproduce asexually

-gets photosynthate, gives plant increased surface are for soil nutrients/moisture

90% of fungi

2 unfused nuclei(n+n)

Ascomycota and Basidiomycota

produces 8 ascospores in an ascus

discharged by turgor pressure

nematode wranglers: specialized structures or sticky hyphae to capture nematodes

Ex: cup/sac fungi, morels, truffles, most yeasts and molds, lichens

(aka club fungi)

produce 4 basidiospores in basidium

spores are discharged passively

Ex: rust and smut (serious plant pathogens), mushrooms, brackets (grow on wood)

changes in allele frequency over time

descent with modification

-genetically-based changes from a common ancestor

Ex: antibiotic resistance in bacteria, adult lactose tolerance, morphological diversity in dogs

A: evolution within a lineage

C: (aka speciation) evolution that results in a splitting of a lineage

ANY GENETIC CHANGE in a population

may occur through: natural selection, migration, mutation, genetic drift

-processes not fundametally different than macroevolutionary ones

source of genetic variation

ANY heritable changes to DNA

variants are then shuffled by meiotic recombination and moved by dispersal

can be:inconsequential, deleterious, or advantageous

*every human, every generation approx. 10 mutations

any mutation that alters a single nucleotide base

synonymous/silent: no amino acid change, no functional consequence

non-synonymous/replacement: cause amino acid changes, functional change

Diseases: progeria, hemophilia, sickle cell anemia

aren't multiples of 3 bases = frame-shift mutations

insertion or deletion of base pairs, altering the proteins coded for

Regulatory Mutations

can be point, insertion, deletion, any

-mutations in the upstream regulatory region of a gene can change expression level(amount of RNA transcription)

Loss of Function Mutations

Frameshift insertion/deletions

large deletions

some point mutations at critical nucleotide sites

raw material for evolutionary change

without genetic variance, evolution CAN'T HAPPEN

mechanism to change allele frequencies, thus evolution

-organisms face many obstacles to survive and reproduce

-advantageous alleles will increase in freq over time in a population

-chance events can alter allele frequencies in populations

-combining gametes from one generation to make the next is subject to chance shifts in allele frequency

-gene flow = genetically effective migration

-movement of individuals between differentiated populations can cause change in allele frequencies

p² + 2pq + q² = 1

predict the genotype frequencies in the next generation

Assume: No migration, No mutation, No selection, No genetic drift (infinite pop size), Random mating, Diploid and Sexually reproducing organism

=average genetic contribution individuals of a particular genotype make to the next generation(reproduce and survive)

Depend on: genotype to determine phenotype, the environment

Absolute fitness (R) = raw success of each genotype

Relative fitness (w_i) = relative contribution made to the next generation by individuals of a genotype

w_i = R_i

       R_ref

take averages of number of offspring and put them over the highest one

Population mean Fitness

   w =

each genotypic frequency multiplied by the corresponding w_i and added together

(s_i)

for genotype i,

s_i=w_ref - w_i

s_i is a measure of the strength of selection against genotype i

selection against deleterious alleles

strong PS = departure from HWE

(on normal dist, deletes the extremes)

mutation producing "a", selection eliminating "a" there is an equilibrium frequency= q_eq

(selection and mutation w/ same effieciency)

q_eq = √(mutation rate/ selection coeffiecient)

-genetically simple directional selection

-over time, the advantageous allele is selected for, increasing in frequency

-once freq reaches 1, there is no evolution = fixed

-rate of fixation depends on dominance

-co-dominance is shortest, dominant next, recessive stays small on bottom(unless =.25 and advantageous)

-selection will ultimately "fix" one or the other allele, the other completely lost

-genetic polymorphism is short-lived within populations

Consequences on isolated pops: reduce within-pop variation, becomes "fixed" for one allele, hybrids have reduced fitness

-in any population with finite size, random genetic drift will change the frequency of an allele over time

-force that reduces genetic variation in populations

-the probability that an allele will ultimately become fixed is exactly equal to its current frequency in the population

-"updates" every generation,no memory of the frequency in previous generations

predicts level of heterozygosity (H)

H=4Nx(mutation rate)

     1 + 4Nx(mutation rate)

N = pop size

smaller populations have: high probability of large frequecy jumps in any given generation, shorter expected time to fixation, genetic drift is strong

large populations: drift is minimal and selection is more powerful

effective population size (N_e) = idividuals that contribute genes to next generation, those that reproduce

if N_e x s<1 drift is stronger

if N_e x s >>1, selection is stonger

the frequencies of A and a find an equilibrium at "intermediate frequency": if fitnesses equal, p = q = .5

-fitness of allele or genotype is not constant,but

depends on its frequency in the population

Negative FD : rare alleles have higher fitness than common ones

-temporary reductions in population size

-mechanism of genetic drift

-accelerated random change in allele frequencies

-loss of genetic variability

-special case of bottlenecks

-small populaton is founded by a few individuals

-loss of genetic variability

-causes genotype frequencies to deviate from HWE

-immigrants must reproduce successfully

-movement and incorporation of genes from one population tinto the gene pool of another population

-causes homogenization of populations, opposes diversifying evolution due to selection and drift

-increases genetic variation if new allels introduced

- unidirectional migration from source to sink (continent to island) at rate m per generation

(sink freq after migration)p'_sink=mp_source + (1-m)p_sink

Drift + Migration: migration homogenizes, drift diversifies, Nm <<1 diversifies, >>1 homogenized

Drift + Selection: N_e*s<1 drift stronger, N_e*s>>1 selection stronger

Migration + Selection: depends on if the allele is advantageous or not

-traits influenced by environment

-vary continuously within populations

Ex: body size, growth rate, age of maturation, number of vertebrae

Directional: mean changes, trait variance decreases

Stabilizing: mean stable, trait variance decreases

Disruptive: mean stable, trait variance increases

V_P = overall phenotypic variance

V_G= genotypic variance - determined by genetic variation

V_E=environmental variance - determined by environmental heterogeneity

V_P = V_{G +}V_E

measures are context-dependent

Broad Sense Heritability = V_G/V_P

proportion of phenotypic variance in a trait w/ simple genetic basis

0<(h²) <1

h²= V_A/V_p

= V_A/ V_A + V_D + V_E

V_A = additive genetic variance

V_D = dominance variance

heritability predicts how well population will respond to directional selection

R=h²S

S = selectin differential, difference between mean trait value in pop and mean for individuals chosed to breed = M_s-M_p

R= response to selection