Table 1. Record of the population sizes of all species in a community after 200 weeks according to type of simulation.
Species
All predators present
All predators absent
Without Whelk
Without Chiton
Without Starfish
Only
Whelk
Only
Chiton
Only Starfish
Algae 1
(Nori)
100
2
62
95
6
6
1
75
Algae 2
(Black pine)
152
2
98
139
7
12
0
119
Algae 3
(Coralweed)
211
1
161
275
16
29
1
212
Mussel
185
1482
83
254
1182
1129
1365
67
Barnacle 1
(Acorn)
160
9
493
167
44
66
7
478
Barnacle 2
(Gooseneck)
76
126
233
104
149
172
106
186
Whelk
(Snails)
87
101
3
4
Chiton
31
4
2
1
Starfish
28
69
23
77
Name______________________________________
1. Which simulation promoted the greatest degree of species diversity? How?
The simulation when all predators were present. The reason is because when predators, specifically starfish, are present the mussel population along with populations of all the rest are able to be controlled. This results in mussels not taking over using their competitive dominance allowing other prey to thrive so that the other predators can survive and be part of the ecological diversity.
2. Which simulation promoted the lowest degree of species diversity? How?
The lowest degree came when all predators were absent. One of the predators, starfish, keeps the mussel population in check and controlled. Because mussels have competitive dominance over the other species, they completely win out and control the area. This results in a lot of mussels and very little of anything else.
3. Which combinations led to the extinction of prey species and also the predator(s) that was (were) initially present?
When only Chiton was present, the entire population of black pine went extinct. Nori, Coralweed, and Chiton in that same simulation sunk to dangerously low levels nearing extinction. When all predators were absent Coralweed, black pine, and nori all nearly went extinct. Also, with