Technical Terms

1. Fitness reduction

2. Disrupt beneficial genetic combinations -

loss of adaptations to a particular habitat

3. Mating process requires energy and time

4. Dependency on partners

A bad mutation is past to all offspring

Bad mutants accumulate every generation

Combining good genes of two semi-functional organisms to one functional organism

Offspring are the result of genetic recombination Bad mutants accumulate less

…sexual recombination

Co-evolutionary arms race: Evolve in order to persist

‘’…it takes all the running you can do, to keep in the same place’’

one plant individual with one type of flowers (male or female)

• mechanism to enforce allogamy

Androdioecy is a reproductive system characterized by the coexistence of males and hermaphrodites.

Gynodiözie ist eine Form der Geschlechtsverteilung bei Blütenpflanzen: In einer Population gibt es weibliche Pflanzen und zwittrige Pflanzen (mit zwittrigen Blüten).

male and female organs on one flower

separate male and female flowers on one plant

self pollination – no sexual reproduction

Form der sexuellen Fortpflanzung, bei der nur ein Elternteil vorhanden ist oder genetisch zur Fortpflanzung beiträgt. Das bedeutet, dass ein Individuum in der Lage ist, sowohl weibliche als auch männliche Gameten zu bilden.

Als Geitonogamie (von griechisch γείτων geiton, deutsch ‚Nachbar' und γαμεῖν gamein, deutsch ‚heiraten') oder Nachbarbestäubung, auch Geitenogamie, wird die Bestäubung einer Blüte mit dem Pollen einer anderen Blüte derselben Pflanze bezeichnet.

Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, peas, and pansies, this behavior is most widespread in the grass family. However, the largest genus of cleistogamous plants is Viola.

cross pollination - sexual reproduction

Genetic mechanisms that prevent the germination of pollen on

stigmas, or the elongation of pollen tubes in the styles

The ripening of the stamens and pistils of a flower at different times

2 or 3 morphological types of flowers exist in the population. The flower morphs differ in the lengths of the pistil and stame On each individual plant, all flowers share the same morph.

• Many pollen grains land on the stigma

• In some species, the competitive ability of pollen-tubes correlates with the growth of the offspring

• nectar

• heat

• size

• color

• smell/pheromones

• shape

Male partners are rivals for mating the most females

• Reproductive success is limited by resources required for the production of offspring

Female Partners: Reproductive success is limited by the availability of mating partners

One visit is enough to secure full success

Many visits are required to remove all pollen

The gain from attracting many pollinators is higher for the male function

• Yellow or blue

• Sweet-smelling

• Nectar produced during the day

• Landing platform

• Red or orange

• Shape with long tubes

• Little scent

• Nectar produced during the day

• Reduced landing platform

• White

• Shape with long tubes

• Night-opening

• Sweet scent produced in the evening, night or early morning

The tendencies of pollinators to visit flowers of a single species or morph even when other alternatives are available

Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic (wind and water) or biotic, such as birds, bees, flies, and so forth through a process called pollinator-mediated selection.

In social foragers, specializing on a specific flower type can decrease competition between workers from the same colony and therefore increase foraging efficiency

Departure from a flower or a patch could be triggered when the reward falls below an innate threshold

Pollinators also sample other flowers to keep track of changing rewards and may change their preference after a sequence of low rewards

Foragers should leave a patch when the rate of reward falls below that of the habitat average

• Amount of reward

• How fast is it depleted

• Travel costs

When travel costs are high, the time spent in a patch will increase

Foragers will equalize the rate of reward gain in all patches by matching the number of foragers to the rate of reward production per patch The number of pollinators per patch should match the amount of reward produced in the patch.

• Orchids often occur in small, scattered populations

• Rewarding pollinators will not increase constancy and therefore have little benefits

• Allocation to floral display is even more important to attract pollinators than nectar

In Orchids the pollen is found in a pollinia: mass of pollen grains that are transferred by pollinators as a single unit

• Reduced need for rewards that encourage multiple visits by pollinators

• Orchids evolved adhesive attachment of the Pollinia

• Reduced transport loss

• Reduced need for rewards that encourage multiple visits by pollinators

a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, who worked on butterflies in the rainforests of Brazil.

Close matching of color and shape of the flowers of a particular model food plant

Conditions for the evolution of Batesian flower mimicry:

• Animal pollination

• Overlapping distribution

• Overlapping flowering phenology (timing)

Imitation of general floral signals typical to rewarding plants (flower shape and color, scent), rather than a specific rewarding species

A rewarding “magnet” species can increase the local abundance of pollinators

Rewarding neighbors increase the pollination success of non-rewarding neighboring plants

Non-rewarding species are inferior competitors for pollination services

Reproductive success will be higher when separated from rewarding species (in space or time)

Species of similar character and in similar abundance evolve a common "advertising style" to their mutual advantage

In plants: Both species provide reward to pollinators Pollinators do not distinguish between the species when approaching flowers in choice tests

1. Increased detectability (contrasting green leaves)

2. Signal the presence of nutritional rewards

3. Advertise ripening

They use sweet smells instead

1. Higher chance of survival

2. Large frugivores as dispersers (larger home range)

A shared trait between different families that are attractive for dispersers

Ripe/overripe fruits produce alcohol and can be detected by their smell of ethanol

1. Capsaicin (spicy taste) poisons mammals but not birds

2. Hot and non-hot fruits

3. Fruits that turn poisonous if seed is chewed

4. Mimetic seeds that pretend to have fleshy reward

Dispersal as factor to increase chance of suvival

Increased chance of suitable habitat

Non-random seed deposition

Fruit needs characteristics to ensure specific mode of transport

• Higher chance of survival further from parent plant due to density-dependant mortality

• Reduced sibling competition

• Reduced predation and specialist pathogens

• Less herbiory

• backup

• Some that ensure long distance dispersal

Due to a somewhat fixed dipersal distance and survival distance tropical forests show a reaccuring pattern of plant societies

• high species diversity

• Low density of each species

• Regular distributed adults

• Enable plant coexistance

Constraints of seed size

…otherwise uncomfortable/noticable

• Long distance dispersal

• Variety of dispersal animals

• should not bee concpicuous

• Adhesive qualities

• Should not harm animals

• fruit attracts diverse dispersers

• animal will eat pulp on site and not disperse seeds

• Disgestions might harm seed

• small and tough seeds enclosed in fleshy fruits

Seed predators: eats/kills seed

• reduced predation risk (because seed is put somewhere safe)

• Increased chance of establishment (seed can grow in underground, nutrient rich ant burrow)

Dispersal type where a seed is transported into an ant burrow because of a lipid-rich attachment (elaiosome)

• seed might not be dispersed

• Short distance dispersal

• some seeds have elaiosome (lipid rich attachment)

Harvesting seeds for later (squirrel)

• seeds are protected from other seed predators and if left uneaten may survive to germinate

Main seed predators in arid regions

Neglected nests serve as improved establishment sites:

• nutrient rich

• Greater water retention (reduced soil crust)

• Reduced competition

Seeds are harvested and stored in one large spot

• recovery of seeds (is very probable)

• Deep burial might prevent germination

Seeds are placed in several small caches

• seed recovery is less likely

• Burial depth is preferable (less deep)

Increase likelyhood of storage:

• large nutritious seeds

• Increase handling time (physical barriers)

Decrease likelihood that seeds are recovered

• Increase search time (hard to find, no strong odors)

• Synchronized reproduction of large amounts of seeds at intervals of several years

Vicia sativa: grows two kinds of seeds, hard for dispersal and germination, soft for reward

Seeds resemble herbivore dung attract dung beetles that roll and bury them for offspring

Two phases of dispersal:

1. seeds moves away from parent plant

2. Directed dispersal (increased establishment chances)

Or

One animal eats seed

Another eats the first animal and increases dispersal

A result of searching time and handling time

C=a*Ts*N

• C=consumption rate

• a=searching efficiency

• Ts= time available for searching

• N=density og pray

Explained by Holling disc equation

Transport in digestive system

Foraging time

Mammals that aquire nutrients from plants by fermenting in a spcialized stomach

A consumtion rate where there is no handling time

• linear

• Only dependant on prey density

A consumtion rate where a moderate handling (also limiting factor) time is included

• low prey density: limiting factor is searching time

• Infinitly abundant prey: limiting factor is handling time

• Highest proportion of prey consumed at lowest prey densities (potential to eliminate prey entirely)

• consumption rate is highest at intermediate prey density and lowest at zero

• Prey at low density have access to hiding places (increased searching time)

When plant biomass turnover equals vegetation growth rate-total consumption rate by herbivores

Vegetation growth rate is dependant on vegetation density

None

Plant fintess (biomass) of damaged plants is lower than undamaged plants

Plant fitness (biomass) of damaged plants equals undamaged plants

Plant fitness (biomass) of damaged plants is higher than in undamaged plants

• herbivory early in the growth season

• The migratory nature of herbivores provides plants time to recover between herbivory bouts

• Increased nutrient availability from dung and urine

• no branching before herbivory arrival

• Dormant meristems in reserve unitl herbivory

• avoidance

• Resistance

• Tolerance

• hard to find (decreasing probability to be eaten)

• Looks like a rock, turns smaller

• reducing the amount of damage done by herbivores

• Structural resistance: Being spikey, hairy

• Chemical resistance: toxic

• low concentrations

• secondary metabolites

• N-based

• Examples: alkaloids, morphine, nicotin, caffeine

• reduce digestibility

• Primary and secondary metabolites

• Occur in high concentrations

• C-based

• Examples: mustard, tannins

under limiting resource carbon

When nitrogen is limited

• direct: allocation, auto-toxicity

• Indirect: deterrence of mutualist

Proper timing

• the identity or severity of herbivores varies across time and space

• Cues about past damage are reliable predictors of future damage

• plant hormones

• Auto signal, intra/interspecific signal

• plant lures carnivores to feed on herbivores

In stressfull/arid environments

In productive environments

• reduction of photosynthetic leaf area

• Removal of active apical meristems

• Loss of nutrients from growth reserves and shoots

• increased light intensity to remaining tissues: increased photosynthetic rate

• Increased allocation of photosynthates to new leaves instead of stem and roots

• Activation of dormant meristems

• induces defences

• Activates compensatory growth

• Good up to tipping point

• erect tall shoots

• Elevated buds

• Long growth season

• Perennial Life cycle

• Palatable to grasers

• short of horizontal shoot

• Near or below-ground buds

• Short growth season

• Annual or short perennial

• Low palatability

• High growth rate

• plants that appear only after herbivory events and increase in abundance with additional herbivory

• intensity and timing of grazing between sites and years

• Site conditions (soil) and year conditions (rainfall)

• Adaptations to grazing vary across ecotypes

• low herbivore density: higher selectivity (decrease of certain species)

• High herbivore density: low selectivity, maintaining similiar composition

Some plant defences are strong enough to not be eaten despite high herbivore density

• usually do not reduce the biomass of competitive species: no competitive release

• Create few disturbance to the soil and conpy: no colonization opportunities

• Will have weak effect on plant diversity at any scale

• can reduce the biomass of dominant species

• Digging can create soil disturbance that enhace colonization

• Will increase plant diversity at a small scale

• High preference to forage next to cover to avoid predators could increase spacial vatiation in vegetation

• Will increasr diversity at larger spatial scales

• eat competitively dominant plants

• Create frequent, small disturbances across the landscape

• Will increase plant diversity at a small scale

• Can be efficient seed dispersers by transporting soil and seeds over larger distances

• Spatially heterogenous urine deposition could increase soil heterogeneity

• Will increase diversity at larger scales

a trait that evolved independantly in different taxa

The leaves are modified into pitfall traps, which contain a pool of digestive enzymes or bacteria

Lid to prevent escape

and too much rain in the pitcher

Smooth or waxy layers make pitfall slippery

Pool with rainwater or digestive fluid

Leaves have many glands that secret a sticky substance, called mucilage and digestive enzymes

a directional growth movement which occurs as a mechanosensory response to a touch stimulus. Thigmotropism is typically found in twining plants and tendrils, however plant biologists have also found thigmotropic responses in flowering plants and fungi.

Modified leaves with active rapid leaf closure

Closure is triggered by action potentials generated by touch of sensitive hairs

After closure – stimulation of the internal surface by moving insects causes tight sealing and release of digestion enzymes

Bladders attached to leaves and suck prey with vacuum

When hairs are touched –bladder opens to suck water and prey in

Channels pump ions out and water follows in osmosis to create a vacuum

Force protozoa to move towards a digestive organ

a chamber that is easy to enter but difficult to exit

Flypaper traps but no secretion of digestive enzymes

Instead - mutualism with a symbiotic bug that lives on the plant and feeds on the trapped insects

The plant obtains nutrients from its droppings through the thin cuticle

Orchids often occur in small, scattered populations

Rewarding pollinators will not increase constancy and therefore have little benefits

Allocation to floral display is even more important to attract pollinators than necta

In Orchids the pollen is found in a pollinia: mass of pollen grains that are transferred by pollinators as a single unit

Reduced need for rewards that encourage multiple visits by pollinators

Orchids evolved adhesive attachment of the Pollinia

Reduced transport loss

Reduced need for rewards that encourage multiple visits by pollinators

The similarity of the mimic to the model affects the behavior of the operator and consequently enhances the fitness of the mimic - resemblance must be adaptive

Close matching of color and shape of the flowers of a particular model food plant

• Overlapping distribution

• Overlapping flowering phenology (timing)

• Animal pollination

Imitation of general floral signals typical to rewarding plants (flower shape and color, scent), rather than a specific rewarding species

Rewarding neighbors increase the pollination success of non-rewarding neighboring plants

A rewarding “magnet” species can increase the local abundance of pollinators

Non-rewarding species are inferior competitors for pollination services

Reproductive success will be higher when separated from rewarding species (in space or time)

Orchids exploit the tendency of pollinators to react to large and visible colored displays

Sensory bias:

Some traits better stimulate the sensory system of the operator

Cognitive bias:

Animals use generalization during associative learning

Species of similar character and in similar abundance evolve a common "advertising style" to their mutual advantage

Plant species that benefit by sharing the same pollinator

Both species benefit from the mimicry

Particularly if both or one species are rare

• Yellow or blue

• Sweet-smelling

• Nectar produced during the day

• Landing platform

• Red or orange

• Shape with long tubes

• Little scent

• Nectar produced during the day

• Reduced landing platform

• White

• Shape with long tubes

• Night-opening

• Sweet scent produced in the evening, night or early morning

because of limited photosynthetic leaf area stomata are constantly open -> risk of drought

High pollination efficiency

• no interspecific pollen transfer

• minimized pollen wastage and stigma clogging

High visitation rates

• better to have a generalist then nothing

The tendencies of pollinators to visit flowers of a single species or morph even when other alternatives are available

Insects can only identify and handle one flower type or species at a time

But… bees are known to store a lot of information (nest location, location of flower patches) They have a long-term memory

Learning a new skill, such as how to stand in the best position on the flower to obtain nectar in a new species, requires investment and time and can be inefficient

Darwin: learning new skills damages ability to remember previous skills

The switch between different food types can result in reduced efficiency

Animals should search only for a single food type at any given time while ignoring alternatives that are equally rewarding and abundant

In social foragers, specializing on a specific flower type can decrease competition between workers from the same colony and therefore increase foraging efficiency

Fidelity to particular species allows foragers to:

• Learn correct handling skills - reduce handling time

• Learn a particular search image – reduce search time

Departure from a flower or a patch could be triggered when the reward falls below an innate threshold

Pollinators also sample other flowers to keep track of changing rewards and may change their preference after a sequence of low rewards

Slot machines with unknown reward probability

A gambler must decide:

• Which slot machine to play?

• How many times to play each machine?

What is the best strategy?

Foragers should leave a patch when the rate of reward falls below that of the habitat average

• Amount of reward

• How fast is it depleted

• Travel costs

Plants that have adaptations for active attraction, capture and/or digestion of prey

Plants that can absorb nutrients from prey

must fulfill both requirements

1. Ways and resources to attract prey

1. Ways and resources to capture prey

2. Ways and resources to digest prey

3. Reduced photosynthetic rate per leaf area

1. Improved mineral acquisition

2. Heterotrophy: use of organic carbon for growth (though not very common)

sunny, moist and nutrient-poor environments

• red leaves

• blue florescent rim

• smell

• nectar reward