|
Records |
Links |
|
Author |
Gardner, A., West, S. A. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Cooperation and Punishment, Especially in Humans |
Type |
Journal Article |
|
Year |
2004 |
Publication |
The American Naturalist |
Abbreviated Journal |
Americ. Natur. |
|
|
Volume |
164 |
Issue |
6 |
Pages |
753-764 |
|
|
Keywords |
kin selection, neighbor-modulated fitness, repression of |
|
|
Abstract |
Explaining altruistic cooperation is one of the greatest
challenges faced by sociologists, economists, and evolutionary biologists.
The problem is determining why an individual would carry
out a costly behavior that benefits another. Possible solutions to this
problem include kinship, repeated interactions, and policing. Another
solution that has recently received much attention is the threat
of punishment. However, punishing behavior is often costly for the
punisher, and so it is not immediately clear how costly punishment
could evolve. We use a direct (neighbor-modulated) fitness approach
to analyze when punishment is favored. This methodology reveals
that, contrary to previous suggestions, relatedness between interacting
individuals is not crucial to explaining cooperation through punishment.
In fact, increasing relatedness directly disfavors punishing
behavior. Instead, the crucial factor is a positive correlation between
the punishment strategy of an individual and the cooperation it
receives. This could arise in several ways, such as when facultative
adjustment of behavior leads individuals to cooperate more when
interacting with individuals who are more likely to punish. More
generally, our results provide a clear example of how the fundamental
factor driving the evolution of social traits is a correlation between
social partners and how this can arise for reasons other than genealogical
kinship. |
|
|
Address |
University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
|
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
refbase @ user @ |
Serial |
341 |
|
Permanent link to this record |
|
|
|
|
Author |
Cameron, E.Z.; du Toit, J.T. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Winning by a neck: tall giraffes avoid competing with shorter browsers |
Type |
Journal Article |
|
Year |
2007 |
Publication |
The American naturalist |
Abbreviated Journal |
Am Nat |
|
|
Volume |
169 |
Issue |
1 |
Pages |
130-135 |
|
|
Keywords |
Acacia/growth & development; Animals; Feeding Behavior/*physiology; Neck/*anatomy & histology; Plant Leaves/growth & development; Ruminants/*anatomy & histology/*physiology; South Africa |
|
|
Abstract |
With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild. |
|
|
Address |
Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
English |
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1537-5323 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
PMID:17206591 |
Approved |
no |
|
|
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
refbase @ user @ |
Serial |
410 |
|
Permanent link to this record |