Frequency dependence and cooperation: theory and a test with bacteria
Hamilton's inclusive fitness theory provides a leading explanation for the problem of cooperation. A general result from inclusive fitness theory is that, except under restrictive conditions, cooperation should not be subject to frequency-dependent selection. However, several recent studies in...
| Main Authors: | , , , |
|---|---|
| Andre forfattere: | |
| Format: | Journal article |
| Sprog: | English |
| Udgivet: |
University of Chicago Press
2007
|
| Fag: |
| _version_ | 1826288900179492864 |
|---|---|
| author | Ross-Gillespie, A Gardner, A West, S Griffin, A |
| author2 | American Society of Naturalists |
| author_facet | American Society of Naturalists Ross-Gillespie, A Gardner, A West, S Griffin, A |
| author_sort | Ross-Gillespie, A |
| collection | OXFORD |
| description | Hamilton's inclusive fitness theory provides a leading explanation for the problem of cooperation. A general result from inclusive fitness theory is that, except under restrictive conditions, cooperation should not be subject to frequency-dependent selection. However, several recent studies in microbial systems have demonstrated that the relative fitness of cheaters, which do not cooperate, is greater when cheaters are rarer. Here we demonstrate theoretically that such frequency-dependent selection can occur in microbes when there is (1) sufficient population structuring or (2) an association between the level of cooperation and total population growth. We test prediction (2) and its underlying assumption, using the pathogenic bacterium <em>Pseudomonas aeruginosa</em>, by competing strains that produce iron-scavenging siderophore molecules (cooperators) with nonproducers (cheaters) at various ratios, under conditions that minimize population structuring. We found that both the relative fitness of cheaters and the productivity of the mixed culture were significantly negatively related to initial cheater frequency. Furthermore, when the period of population growth was experimentally shortened, the strength of frequency dependence was reduced. More generally, we argue that frequency-dependent selection on cooperative traits may be more common in microbes than in metazoans because strong selection, structuring, and cooperation-dependent growth will be more common in microbial populations. |
| first_indexed | 2024-03-07T02:20:42Z |
| format | Journal article |
| id | oxford-uuid:a3ceb6f6-0ea4-4828-81d1-d660ea64ada4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:20:42Z |
| publishDate | 2007 |
| publisher | University of Chicago Press |
| record_format | dspace |
| spelling | oxford-uuid:a3ceb6f6-0ea4-4828-81d1-d660ea64ada42022-03-27T02:29:38ZFrequency dependence and cooperation: theory and a test with bacteriaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a3ceb6f6-0ea4-4828-81d1-d660ea64ada4BiologyEnglishOxford University Research Archive - ValetUniversity of Chicago Press2007Ross-Gillespie, AGardner, AWest, SGriffin, AAmerican Society of NaturalistsHamilton's inclusive fitness theory provides a leading explanation for the problem of cooperation. A general result from inclusive fitness theory is that, except under restrictive conditions, cooperation should not be subject to frequency-dependent selection. However, several recent studies in microbial systems have demonstrated that the relative fitness of cheaters, which do not cooperate, is greater when cheaters are rarer. Here we demonstrate theoretically that such frequency-dependent selection can occur in microbes when there is (1) sufficient population structuring or (2) an association between the level of cooperation and total population growth. We test prediction (2) and its underlying assumption, using the pathogenic bacterium <em>Pseudomonas aeruginosa</em>, by competing strains that produce iron-scavenging siderophore molecules (cooperators) with nonproducers (cheaters) at various ratios, under conditions that minimize population structuring. We found that both the relative fitness of cheaters and the productivity of the mixed culture were significantly negatively related to initial cheater frequency. Furthermore, when the period of population growth was experimentally shortened, the strength of frequency dependence was reduced. More generally, we argue that frequency-dependent selection on cooperative traits may be more common in microbes than in metazoans because strong selection, structuring, and cooperation-dependent growth will be more common in microbial populations. |
| spellingShingle | Biology Ross-Gillespie, A Gardner, A West, S Griffin, A Frequency dependence and cooperation: theory and a test with bacteria |
| title | Frequency dependence and cooperation: theory and a test with bacteria |
| title_full | Frequency dependence and cooperation: theory and a test with bacteria |
| title_fullStr | Frequency dependence and cooperation: theory and a test with bacteria |
| title_full_unstemmed | Frequency dependence and cooperation: theory and a test with bacteria |
| title_short | Frequency dependence and cooperation: theory and a test with bacteria |
| title_sort | frequency dependence and cooperation theory and a test with bacteria |
| topic | Biology |
| work_keys_str_mv | AT rossgillespiea frequencydependenceandcooperationtheoryandatestwithbacteria AT gardnera frequencydependenceandcooperationtheoryandatestwithbacteria AT wests frequencydependenceandcooperationtheoryandatestwithbacteria AT griffina frequencydependenceandcooperationtheoryandatestwithbacteria |