Research involves

Studying mating systems in three species of spiders across variable habitats to understand links between the environment and individual gene expression.

Research relevance

Shedding light on the effects of social and environmental factors on genetic processes in nature and answering questions in evolutionary biology, genomics and neuroscience.

Extreme Mating and the Changing Spider

With recent advances in genomics, catalogues of genes are now available for many model organisms. In most cases, though, it is still unclear how gene expression will really play out in nature, or in organisms not normally studied in the lab. How do changes in the environment, mating and social behaviour affect gene expression and, as a result, the traits of organisms in the wild?

Dr. Maydianne Andrade, Canada Research Chair in Integrative Behavioural Ecology, is examining variation in gene expression in three species of spiders. Building on her past work on cannibalistic black widow spiders, she plans to test a new theory about how the frequency and conditions of mating shape the evolution of what researchers call “plasticity.”

Plasticity—or variability in gene expression in response to environmental cues—may be more likely in species like the Australian redback spider, because males need to survive and mate under a narrow range of variable conditions shortly after they hit adulthood. On the other hand, more long-lived species, like the Western black widow, mate more than once and are unlikely to change their development in response to short-term changes in their local environment.

The emerging field of integrative behavioural ecology looks to interpret animal behaviour as a function of social, sexual and genetic processes. Andrade’s work in this field is filling a much-needed gap, since it unfolds both in the lab and in the wild. Most studies of this kind have not been conducted in natural habitats, so our understanding of the links between environmental and social factors and physiological and genetic processes has so far been limited.

Andrade’s work will not only help us better understand the threat posed by the specific populations she studies (the black widow’s venom is toxic to humans, and plasticity may increase their invasiveness), but will help us understand how natural conditions shape diversity.