UNIVERSITY OF ARIZONA
Division of labor occurs at all levels of biological organization: for example, cells in a multi-cellular organism just as workers in a social insect colony may specialize on particular tasks. Such specialization can lead to morphological differentiation, and thus to evolutionary innovation. What environmental or social conditions favor such specialization of components, and what system-level organization is needed to reap the benefits of such specialization? The objective of this project is to develop a new, quantitative understanding of the contribution of morphologically distinct specialists to group success. Turtle ants (Cephalotes rohweri) will be used as model system. These ants produce two types of workers, one of which is a highly specialized defense soldier with a plate-shaped head, used to block nest entrances. Because of their costs and inflexibility, the production of specialists is limited. Defense of the colony may thus crucially depend on effective allocation of specialists to the right place at the right time. The project will investigate how this dynamic allocation takes place, and thus how the ant society trades-off risk and resources; it will investigate the contribution of specialists to colony fitness; and a model will be developed to determine the optimal strategy for distributing specialists in a variable work environment. The project will thus offer new insights on important questions about the evolution of specialization. In addition, because it focuses on defense specialists, it will have implications for optimal allocation of defense resources in any system. The results of this project will serve not only to increase understanding of the evolution of specialization, but also help engineers design improved distributed problem solving algorithms, for example in collective robotics.
Choose a quarter and click "Go."
| AWARD OVERVIEW |
| Award Number |
0841756 |
Funding Agency |
National Science Foundation |
| Total Award Amount |
$450,000 |
Project Location - City |
Tucson |
| Award Date |
06/12/2009 |
Project Location - State |
AZ |
| Project Status |
More than 50% Completed |
Project Location - Zip |
85721-0001
|
| Jobs Reported |
1.38 |
Congressional District |
03 |
| Project Location - Country |
US |
|
|
Recipient Information
(Grants)
| Recipient Information (Grants) |
|
Recipient Name
|
UNIVERSITY OF ARIZONA |
| Recipient DUNS Number |
806345617
|
| Recipient Address |
888 N EUCLID AVE |
| Recipient City |
TUCSON |
| Recipient State |
Arizona |
| Recipient Zip |
85719-4824 |
| Recipient Congressional District |
03 |
| Recipient Country |
USA |
Required to Report Top 5
Highly Compensated Officials |
No |
Projects and Jobs Information
| Projects and Jobs Information |
| Project Title |
Adaptive distribution of morphological specialists in social insects: New insights into the evolution of division of labor |
| Project Status |
More than 50% Completed |
| Final Project Report Submitted |
No |
| Project Activities Description |
Ecology, Evolution, Systematics & Population Biology |
| Quarterly Activities/Project Description |
Our aim is to understand how ant colonies deal with risk, by studying the regulation of 'soldier' distribution across nests under different conditions. In addition to studying ants in the field and in the lab, we have completed a modeling study that examines the optimal collective strategy for different environments.
Our results indicate that in ants, nest defense is dependent on resource availability and quality, and constrained by total defensive force available. This is consistent with a sophisticated 'conservative bet-hedging' strategy.
Soldiers are also allocated dynamically according to nest defensibility and threat levels. In the wild, nests are quickly usurped unless they are both highly defensible (small entrance) and well-defended (soldiers present), indicating that ant colony survival hinges on optimizing colony defense strategies. We found that individual soldiers fulfill consistently different roles, in that some remain as stationary defenses whereas others move dynamically among sites. Our modeling study predicts what optimal allocation of soldiers across nests should look like, but our empirical study shows that ants do not always conform to this prediction. We are still analyzing the results from an additional experiment to examine the reason for this. This past quarter, we have finished this last experiment and begun to analyze and write up for publication the final results.
In addition to these activities, we have performed several sub-projects, often under the leadership of students. For example, we completed studies analyzing the network structure of ant interactions; on the adaptive reasons for polydomy (living in multiple sites instead of just one); on the adaptive reasons for inactive workers in ant colonies, and on their circadian rhythm; and on colony-specific differences in aggression and other traits. We also completed three review papers/book chapters on collective behavior. We are finalizing these experiments. |
| Jobs Created |
1.38 |
| Description of Jobs Created |
The prime recipient created or retained a research associate, graduate associate, and student positions |
Purchaser Information
(Grants)
| Purchaser Information |
| Contracting Office ID |
Not Reported |
| Contracting Office Name |
Not Available |
| Contracting Office Region |
Not Available |
| TAS Major Program |
49-0101 |
| Award Information |
| Award Date |
06/12/2009 |
| Award Number |
0841756 |
| Order Number |
|
| Award Type |
Grants |
| Funding Agency ID |
49 |
| Funding Agency Name |
National Science Foundation |
| Funding Office Name |
Not Available |
| Awarding Agency ID |
49 |
| Awarding Agency Name |
National Science Foundation |
| Amount of Award |
$450,000 |
| Funds Invoiced/Received |
$415,475 |
| Expenditure Amount |
$415,480 |
| Infrastructure Expenditure Amount |
$0 |
| Infrastructure Purpose and Rationale |
Not Reported |
| Infrastructure Point of Contact Name |
Not Reported |
| Infrastructure Point of Contact Email |
Not Reported |
| Infrastructure Point of Contact Phone |
Not Reported |
| Infrastructure Point of Contact Address |
Not Reported |
| Infrastructure Point of Contact City |
Not Reported |
| Infrastructure Point of Contact State |
Not Reported |
| Infrastructure Point of Contact Zip |
Not Reported |
Product or Service Information
(Grants)
| Product or Service Information |
| Primary Activity Code |
U02.04 |
| Activity Description |
Ecology, Evolution, Systematics & Population Biology |
| Sub-Awards Information |
| Sub-awards to Organizations |
0 |
| Sub-award Amounts to Organizations |
$0 |
| Sub-Awards to Individuals |
0 |
| Sub-Award Amounts to Individuals |
$0 |
| Number of Sub-awards less than $25,000/award |
0 |
| Amount of Sub-awards less than $25,000/award |
$0 |
| Number of payments to vendors greater than $25,000 |
0 |
| Total Amount of payments to vendors greater than $25,000/award |
$0 |
| Number of payments to vendors less than $25,000/award |
109 |
| Total Amount of payments to vendors less than $25,000/award |
$19,363 |
| Location Information |
| Latitude, Longitude |
32º 13' 54",
-110º 56' 57" |
| Congressional District |
03 |
| Address 1 |
|
| Address 2 |
|
| City |
Tucson |
| County |
Pima |
| State |
AZ |
| Zip |
85721-0001 |
|
|