Developmental Plasticity and Symbiosis • • • • Environment is not as bad as we thought Reaction Norm vs. Polyphenism Environmental regulation of phenotypes Learning Nature vs Nurture? Plasticity • Phenotypic • Developmental Reaction Norm Polyphenism Dung Beetles and Ants: Diet-induced polyphenisms • Queen Ant vs Worker Ant • Horned male Dung Beetles: Protector of the Female. Diet and Gene regulation • DNA methylation • viable-yellow of Agoutitransposon in cis-regulatory element. Predator-induced Polyphenisms • Kairomones Predator-induced Polyphenisms: Amphibians • More muscle mass in tail. • Kairomones can make the tadpole more sensitive to environmental insults: fertilizers et al. Figure 17.6 Good Vibrations Fig. 17.7 Geronimo Temperature and Sex Temperature and Butterfly wings Environment, Anxiety, and DNA methylation Learning • No division • New Neurons • Changing connections Nervous system: Plasticity and Learning Experience and vision • Hubel and Wiesel (1960s) • Right eye occluded for 3 months • Occurs within 4 to 6 weeks of birth Life cycle and Polyphenisms • Diapause • Larval Settlement Spadefoot Toad Symbiosis • Parasitism • Mutualism • Commensalism Developmental Symbiosis: passing on the help • Vertical transmission • Horizontal transmission • Wolbachia infection Shedding light on symbiosis • Euprymna-Vibrio • Light organ development and luminescence Obligate mutualism Filariasis worm and Wolbachia Spotted Salamander and Oophilia amblystomatis Symbiosis in mammalian intestine