EVOLUTIONARILY STABLE SIZE OF A MEGAGAMETOPHYTE: EVOLUTION OF TINY MEGAGAMETOPHYTES OF ANGIOSPERMS FROM LARGE ONES OF GYMNOSPERMS
Article first published online: 8 NOV 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 2, pages 539–547, February 2013
How to Cite
Sakai, S. (2013), EVOLUTIONARILY STABLE SIZE OF A MEGAGAMETOPHYTE: EVOLUTION OF TINY MEGAGAMETOPHYTES OF ANGIOSPERMS FROM LARGE ONES OF GYMNOSPERMS. Evolution, 67: 539–547. doi: 10.1111/j.1558-5646.2012.01789.x
- Issue published online: 28 JAN 2013
- Article first published online: 8 NOV 2012
- Accepted manuscript online: 3 SEP 2012 12:00PM EST
- Received April 2, 2012 Accepted August 7, 2012
- embryo sac;
- game theory;
To examine the factors favoring large megagametophytes of gymnosperms and tiny ones of angiosperms, a game model for seed production was developed in which megagametophytes growing in the same female parent compete for resources provided by the parent. In the model, megagametophytes may continue to grow until seed completion or may cease to grow at a certain time and regrow at pollination or fertilization. Autonomous abortion of unpollinated or unfertilized megagametophytes may occur either at pollination or fertilization. Those megagametophytes absorb a certain amount of resources before abortion, due to constraints in the signal process, in addition to the resources absorbed before pollination or fertilization. It was found that both growth habits can be the ESS: megagametophytes continue to grow without cessation and monopolize resources, such as gymnosperms, or cease to grow until fertilization to reduce the loss of resources due to autonomous abortion, such as angiosperms. The former and the latter are the ESS if the time interval between pollination and fertilization is long and short, respectively. Thus, the fertilization interval may be a critical factor selecting for large megagametophytes of gymnosperms or tiny ones of angiosperms.