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 Agouti-

transposon 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

Spotted Salamander and Oophilia amblystomatis

Filariasis worm and Wolbachia

Symbiosis in mammalian intestine