#### 0400: Feedback loops

##### Niall Palfreyman

This is a collection of models which illustrate the idea of

1. The first is an

2. The second model contains a

3. The third model contains a

**feedback loops**, which form the basis of all living systems.1. The first is an

**open-loop model**- that is, it contains no feedback. The process of gravitational acceleration g changes the speed of a falling ball, but this speed has no feedback effect on gravity.2. The second model contains a

**positive feedback**loop. A greater number of Bacteria causes the number of cell divisions to increase, and the process of cell division itself also increases the number of Bacteria. The process 'division' and the state variable 'Bacteria' both have a positive effect on each other, generating unconstrained growth.3. The third model contains a

**negative feedback**loop. A greater number of TumourCells causes the number of cell deaths to increase, but the process of cell death itself decreases the number of TumourCells. The process 'death' negatively influences the state variable 'TumourCells', while 'TumourCells' positively influences 'death', causing the TumourCells to decay to zero.- 2 years 6 months ago

#### Daisyworld

##### France Caron

Darwinian Daisyworld model from and Watson & Lovelock (1983), Robertson & Robinson (1998) and Lenton & Lovelock (2001).

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

Based on 0409-DaisyworldInsight Original Author: Niall Palfreyman

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

Based on 0409-DaisyworldInsight Original Author: Niall Palfreyman

- 8 months 1 day ago

#### Mundo De las Margaritas

##### Edgar López

Una pequeña modificación al modelo del mundo de las margaritas, se incluyo una nueva especie de margarita con posibilidad de mutar según vayan cambiando las condiciones de temperatura.

- 1 year 1 month ago

#### Daisyworld modificado - mamenac

##### María Alejandra Mena Castro

Darwinian Daisyworld model from and Watson & Lovelock (1983), Robertson & Robinson (1998) and Lenton & Lovelock (2001).

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 1 year 1 month ago

#### Clone of Clone of 0409: Daisyworld

##### Tobias Meier

Darwinian Daisyworld model from and Watson & Lovelock (1983), Robertson & Robinson (1998) and Lenton & Lovelock (2001).

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 5 months ago

#### Clone of 0409: Daisyworld

##### Adrian Marcus

Darwinian Daisyworld model from and Watson & Lovelock (1983), Robertson & Robinson (1998) and Lenton & Lovelock (2001).

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### testmodel x

##### adriaan

probeer

- 1 year 10 months ago

#### Clone of 0409: Daisyworld

##### Tobias Meier

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### Clone of Clone of 0409: Daisyworld

##### Alexander

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### Clone of 0409: Daisyworld

##### Anna Blümel

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 6 months ago

#### Clone of Clone of The Best Daisyworld 3.0

##### HelloWorld

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 1 year 8 months ago

#### Clone of Clone of Clone of 0409: Daisyworld

##### Anna Blümel

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 6 months ago

#### Clone of 0409: Daisyworld

##### Heinzel

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### Clone of Clone of 0409: Daisyworld

##### Heinzel

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 6 months ago

#### Clone of Influence of Sympatric Speciation on Regulation

##### RS Brückl

We
extended Daisyworld to evaluate the effects of sympatric speciation on
regulation. Sympatric speciation occurs when organisms are segregated
from each other by functional, rather than spatial, constraints. The
dynamical model contains five potential species: gray, light gray, dark
gray, black and white daisies, whose phenotypes differ only in their
albedo.

Initially the model contains only gray daisies. Mutation of gray daisies leads to new daisy types. These new types can interbreed with their genetic neighbors or mutate even further. These mutations ultimately lead to black or white daisies. When two types are functionally different enough they cannot interbreed and we consider them separate species.

'gamma' is the general death rate for all daisies.

The 'Flow' defines the percentage of the actual population which mutates.

'q' defines the spatial distribution of thermal energy between the dasies.

'Base' is the optimal temperature of the general daisy.

'mu' is the probability of a mutation event.

Our model contains two possible luminosity scenarios. One relates to the increasing luminosity of the original Daisyworld. There is a second scenario implemented, which simulates different pertubations over a normally constant luminosity. To change between the scenarios simply reconnect the 'Absorbed Luminosity' variable with one of the container 'L'. Both scenarios are depicted in the diagram, so no changes are neccessary.

Initially the model contains only gray daisies. Mutation of gray daisies leads to new daisy types. These new types can interbreed with their genetic neighbors or mutate even further. These mutations ultimately lead to black or white daisies. When two types are functionally different enough they cannot interbreed and we consider them separate species.

**Instructions:**

You can change the 'Spread' of albedo between the different daisy types centered at the albedo of the gray daisies and in symmetric shades.'gamma' is the general death rate for all daisies.

The 'Flow' defines the percentage of the actual population which mutates.

'q' defines the spatial distribution of thermal energy between the dasies.

'Base' is the optimal temperature of the general daisy.

'mu' is the probability of a mutation event.

Our model contains two possible luminosity scenarios. One relates to the increasing luminosity of the original Daisyworld. There is a second scenario implemented, which simulates different pertubations over a normally constant luminosity. To change between the scenarios simply reconnect the 'Absorbed Luminosity' variable with one of the container 'L'. Both scenarios are depicted in the diagram, so no changes are neccessary.

- 2 years 5 months ago

#### Clone of 0409: Daisyworld

##### RS Brückl

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### Clone of 0409: Daisyworld

##### Heinzel

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 6 months ago

#### Clone of 0409: Daisyworld

##### RS Brückl

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### Clone of 0409: Daisyworld

##### Jan Naahs

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 7 months ago

#### Clone of 0409: Daisyworld

##### Hoepfl

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 5 months ago

#### Clone of Clone of 0409: Daisyworld

##### Cuong Quang

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 6 months ago

#### Clone of 0409: Daisyworld

##### Leidy Muñoz Garcia

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 1 year 1 month ago

#### Clone of 0409: Daisyworld

##### Tobias Meier

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 2 years 6 months ago

#### Clone of 0409: Daisyworld

##### María José Andrade Tafur

Units of time are 40 Myr, giving R&R's span of 10 Gyr.

This model offers many opportunities for modification. Maybe the Black and White populations can mutate into each other? The role of q as a measure of segregation of the B and W populations is interesting, and while this model uses purely stigmergic communication between species, direct interaction would also be possible.

- 1 year 1 month ago