Meeting Abstract
Reproduction is an essential element of the evolutionary process: it underlies the inheritance of traits, and trait variation determines the outcome of both adaptive and non-adaptive evolutionary change. The capacity of the reproductive system to produce viable offspring depends on a number of variables. These can include environmental factors such as nutritional quantity and quality, humidity, temperature, and altitude, and thus reproductive capacity is subject to a great degree of phenotypic plasticity. There are also aspects of reproductive capacity that are heritable, including the structure of the reductive organs, the control of gametogenesis, and the success of fertilization in the case of sexual reproduction. There is also, therefore, a significant genetic component that determines lifetime reproductive output. The combination of these many factors, and the clear contribution of reproduction to fitness, mean that reproductive systems offer exciting contributions to examine outstanding problems at the intersection of development, genetics, evolution and ecology. We will discuss the evolutionary variation, genetic control and ecological influence over one important component of arthropod reproductive systems, namely, the number of ovarioles found in insect ovaries. Ovarioles are individual egg-producing subunits found in all insect ovaries, and the number of ovarioles is a high-fidelity predictor of lifetime egg production for females of the genus Drosophila. We will discuss our findings of some of the genetic and ecological factors that can influence ovariole number in both laboratory-reared and wild-caught populations, and consider whether analogous ovarian structures exist across non-insect arthropods.
