Sugarscape Sexual Reproduction

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WHAT IS IT?

This model in the NetLogo Sugarscape suite implements Epstein & Axtell's Sugarscape Sexual reproduction, as described in chapter 3 of their book Growing Artificial Societies: Social Science from the Bottom Up. It simulates a population with limited, spatially-distributed resources available and 2 differents sex distrbuted among population. In order to can reproduce each turtle must be from different sex and have enough amount of sugar and their age must be in the range of fertility variable.

HOW IT WORKS

The rules are similar to Sugarscape constant grow, in adition each individual has a defined sex, that could be female or male. If an individual finds another turtle from different sex and in a reproductive age and with enough amount of sugar and the turtle is near the caller and there is an empty patch near them, then thay can offspring. Vision and metabolism are passed through generations by random chance or the vision from one parent or the metabolism from the other.

HOW TO USE IT

Set the INITIAL-POPULATION slider before pressing SETUP. This determines the number of agents in the world.

Press SETUP to populate the world with agents and sugar. GO will run the simulation continuously, while GO ONCE will run one tick.

The four plots show the world population over time, the distribution of sugar among the agents, the mean vision of all surviving agents over time, and the mean metabolism of all surviving agents over time.

The two monitors show the amount of turtles belonging to each sex.

THINGS TO NOTICE

The world has a carrying capacity, which is lower than the initial population of the world. Agents who are born in sugarless places or who consume more sugar than the land cannot be supported by the world, and die. Other agents die from competition - although some places in the world have enough sugar to support them, the sugar supply is limited and other agents may reach and consume it first.

As the population stabilizes, the average vision increases while the average metabolism decreases. Agents with lower vision cannot find the better sugar patches, while agents with high metabolism cannot support themselves. The death of these agents causes the attribute averages to change.

You can watch different demographic regimes going through time; inheritance follows mendelian rules.

THINGS TO TRY

Population grows and shrinks until reach some kind of stable state. You can try with different initial populations and test some hypothesis about the influence of this initial state in the final state.

EXTENDING THE MODEL

As mentiones by Axtell & Epstein you can change the way of agent reproduction and avoid reproduction among members of the same family or you can change the sugar inheritance rule once one of the parents die (in current implementation that amount of sugar is vanished from the board).

NETLOGO FEATURES

We use here the matrix extension to build the sugar world.

RELATED MODELS

Other models in the NetLogo Sugarscape suite include:

Sugarscape 1 Immediate Growback
Sugarscape 3 Wealth Distribution
Sugarscape 4 Seasonal Migration
Sugarscape 5 Cultural Dynamics
Sugarscape 6 Sexual Reproduction

CREDITS AND REFERENCES

Epstein, J. and Axtell, R. (1996). Growing Artificial Societies: Social Science from the Bottom Up. Washington, D.C.: Brookings Institution Press.

HOW TO CITE

If you mention this model or the NetLogo software in a publication, we ask that you include the citations below.

For the model itself:

Diaz Cordova, D, (2023). Netlogo Sugarscape 6. Sexual Reproduction. Universidad Nacional de Lanús. Argentina.

Please cite the NetLogo software as:

Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

COPYRIGHT AND LICENSE

CC BY-NC-SA 3.0

This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.

Commercial licenses are also available. To inquire about commercial licenses, please contact Uri Wilensky at uri@northwestern.edu.

Comments and Questions

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Click to Run Model

extensions [matrix]
turtles-own [
  sugar           ;; the amount of sugar this turtle has
  metabolism      ;; the amount of sugar that each turtles loses each tick
  vision          ;; the distance that this turtle can see in the horizontal and vertical directions
  vision-points   ;; the points that this turtle can see in relative to it's current position (based on vision)
  ;culture         ;; a list containing cultural tags
  ;culturecolor    ;; sum of culture list tags
  sexo            ;; set agent sex 1 male 0 female
  edad            ;; set agent age
  muerte          ;; set agent age death
  fertilidadc     ;; set agent age fertility start
  fertilidadf     ;; set agent age fertility end
  dotacion        ;; set agent sugar amount at birth (or creation in the setup routine)
]

patches-own [
  psugar           ;; the amount of sugar on this patch
  max-psugar       ;; the maximum amount of sugar that can be on this patch
]

;;
;; Setup Procedures
;;

to setup
  clear-all
  create-turtles initial-population [ turtle-setup ]
  setup-patches
  reset-ticks
end 

to turtle-setup ;; turtle procedure
  set color red
  set shape "person"
  move-to one-of patches with [not any? other turtles-here]
  set sugar random-in-range 50 100
  ;;guardo la dotacion inicial de azucar
  set dotacion sugar
  set metabolism random-in-range 1 4
  set vision random-in-range 1 6
  ;; turtles can look horizontally and vertically up to vision patches
  ;; but cannot look diagonally at all
  set vision-points []
  foreach (range 1 (vision + 1)) [ n ->
    set vision-points sentence vision-points (list (list 0 n) (list n 0) (list 0 (- n)) (list (- n) 0))
  ]
  ;set culture n-values 11 [random 2]
  ; edad de muerte
  set muerte 60 + random 40
  ; sexo if 1 = male, 0 = female
  set sexo random 2
  set edad 0
  set fertilidadc 12 + random 3
  ifelse sexo = 1
      [set fertilidadf 50 + random 10]
      [set fertilidadf 40 + random 10]
  run visualization
end 

to setup-patches
let m matrix:from-row-list [[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 2 2 2 2 2 2 2 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 3 3 3 3 3 3 3 2 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 3 3 3 3 3 3 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2]
[0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3]
[0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3]
[0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3]
[0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3]
[0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3]
[0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3]
[0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2]
[0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 3 3 3 3 3 3 2]
[1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 4 4 4 4 3 3 3 3 3 3 3 2 2]
[1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2]
[1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2]
[1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2]
[1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2]
[1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2]
[1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1]
[1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1]
[1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1]
[1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1]
[1 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1]
[2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1]
[2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1]
[2 2 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1]
[2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 0 0 0]
[2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0]
[2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0]
[2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0]
[2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0]
[2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0]
[2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2 2 2 2 2 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0]
[2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 2 2 2 2 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0]
[2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0]
[2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 4 4 3 3 3 3 3 3 2 2 2 2 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0]
[2 2 2 2 2 2 3 3 3 3 3 3 3 4 4 4 4 3 3 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
[1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]]
  let i 0
  let j 0
  ;let m1 matrix:transpose m
  ;; let row-i matrix:get-row m i ask patches with [pxcor = i and pycor = j]
  ;[set max-psugar item rowx row-i
  let rowx 49
  repeat 50 [ repeat 50
              [let row-i matrix:get-row m i ask patches with [pxcor = i and pycor = j]
                 [set max-psugar item rowx row-i
                ;ask patches with [pxcor = i and pycor = j] [set max-psugar item rowx (matrix:get-row m i)
                set psugar max-psugar
                patch-recolor
                ]
               set rowx rowx - 1
               set j j + 1
              ]
    set i i + 1
    set j 0
  set rowx 49]
end 
;;
;; Runtime Procedures
;;

to go
  if not any? turtles [
    stop
  ]
  ask patches [
    patch-growback
    patch-recolor
  ]
  ask turtles [
    ;turtle-culture
    turtle-move
    turtle-eat
    if sugar <= 0
      [ die ]
    if edad = muerte
      [die]

    set edad edad + 1
    if (edad >= fertilidadc) and (edad <= fertilidadf) and (sugar >= dotacion)
        [sexear]
    run visualization
  ]
  tick
end 

to parir [metaP visionP metaM visionM dotacionP dotacionM]
  hatch 1 [
     move-to patch-ahead 1
     set color green
     ifelse (random 2 = 0)
       [set metabolism metaM]
       [set metabolism metaP]
     ifelse (random 2 = 0)
       [set vision visionM]
       [set vision visionP]
     set vision-points []
     foreach (range 1 (vision + 1)) [ n ->
         set vision-points sentence vision-points (list (list 0 n) (list n 0) (list 0 (- n)) (list (- n) 0))
          ]
    ifelse (random 2 = 0)
      [set sexo 0]
      [set sexo 1]
    set muerte 60 + random 40
    set edad 0
    set fertilidadc 12 + random 3
    ifelse sexo = 1
      [set fertilidadf 50 + random 10]
      [set fertilidadf 40 + random 10]
    let sugarH (dotacionP / 2) + (dotacionM / 2)
    set sugar sugarH
    set dotacion sugar
  ]
end 

to sexear

let sexoc sexo
let metaP metabolism
let visionP vision
let bnacio false
let dotacionP dotacion
let bvacio false
let metaM 0
let visionM 0
let dotacionM 0
let vecindario turtles-on neighbors4
if (count(vecindario) > 0)
  [ask vecindario [
     set metaM metabolism
     set visionM vision
     set dotacionM dotacion
     repeat 4
       [
       if (sexoc != sexo) and (edad >= fertilidadc) and (edad <= fertilidadf) and (sugar >= dotacion) and (not any? turtles-on patch-ahead 1)
         [
         parir metaP visionP metaM visionM dotacionP dotacionM
         set sugar sugar - (dotacionM / 2)
         set bNacio true
         ]
       set heading heading + 90
       ]
       ;si la pareja no tiene lugar fijarse si hay lugar en el llamador
    if (sexoc != sexo) and (edad >= fertilidadc) and (edad <= fertilidadf) and (sugar >= dotacion) and (bNacio = false)
      [set bvacio true
      ]
    ]
    if bvacio = true
      [repeat 4
        [if (not any? turtles-on patch-ahead 1)
          [parir metaP visionP metaM visionM dotacionP dotacionM
           set bNacio true
          ]
        set heading heading + 90
        ]
      ]
  ]
if bNacio = true
  [set sugar sugar - (dotacionP / 2)]
end 
;to turtle-culture
;  let vecindario turtles-on neighbors4
;  ;; me fijo si hay alguna tortuga en su vecindario
;  if (count(vecindario) > 0)
;    [;; selecciono un tag cultural al azar
;     let rndvalue random 11
;     let culturetag item rndvalue culture
;     ask vecindario [let culturetagV item rndvalue culture
;                     if culturetag != culturetagV
;                        [set culture replace-item rndvalue culture culturetag]
;                    ]
;    ]
;end

to turtle-move ;; turtle procedure
  ;; consider moving to unoccupied patches in our vision, as well as staying at the current patch
  let move-candidates (patch-set patch-here (patches at-points vision-points) with [not any? turtles-here])
  let possible-winners move-candidates with-max [psugar]
  if any? possible-winners [
    ;; if there are any such patches move to one of the patches that is closest
    move-to min-one-of possible-winners [distance myself]
  ]
end 

to turtle-eat ;; turtle procedure
  ;; metabolize some sugar, and eat all the sugar on the current patch
  set sugar (sugar - metabolism + psugar)
  set psugar 0
end 

to patch-recolor ;; patch procedure
  ;; color patches based on the amount of sugar they have
  set pcolor (yellow + 4.9 - psugar)
end 

to patch-growback ;; patch procedure
  ;; gradually grow back all of the sugar for the patch
  ;set psugar min (list max-psugar (psugar + 1))
  ;set psugar max-psugar
  if psugar < max-psugar
    [set psugar psugar + 1]
end 

;;
;; Utilities
;;

to-report random-in-range [low high]
  report low + random (high - low + 1)
end 

;;
;; Visualization Procedures
;;

to no-visualization ;; turtle procedure
  set color red
end 

to color-agents-by-vision ;; turtle procedure
  set color red - (vision - 3.5)
end 

to color-agents-by-metabolism ;; turtle procedure
  set color red + (metabolism - 2.5)
end 

to color-agents-by-culture
  set color red
;  set culturecolor reduce + culture
;  ifelse culturecolor > 5
;    [set color red]
;    [set color blue]
;  ;[set color scale-color red culturecolor 0 10 ]
;    ;[set color scale-color blue culturecolor 0 10]
end 

; Copyright 2009 Uri Wilensky.
; See Info tab for full copyright and license.

There is only one version of this model, created over 2 years ago by Diego Díaz Córdova.

Attached files

File	Type	Description	Last updated
Sugarscape Sexual Reproduction.png	preview	Preview for 'Sugarscape Sexual Reproduction'	over 2 years ago, by Diego Díaz Córdova	Download

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