Early Vertebrate Developement

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