Developmental BiologyDevelopmental Biology

An IntroductionAn Introduction

Animal DevelopmentAnimal Development How has the study of How has the study of

development changed?development changed?

Animal DevelopmentAnimal Development

What kinds of questions areWhat kinds of questions aredevelopmental biologists asking?developmental biologists asking?

Animal DevelopmentAnimal Development

How does the same genetic information result in different types of cells?

Animal DevelopmentAnimal Development How is cell division regulated?How is cell division regulated?

Animal DevelopmentAnimal Development How do cells form ordered structures?How do cells form ordered structures?

Animal DevelopmentAnimal Development How are reproductive How are reproductive

cells set apart?cells set apart?

Animal DevelopmentAnimal Development

How do changes in development create new

body forms and what changes are possible?

Animal DevelopmentAnimal Development How do each of these contribute to the study How do each of these contribute to the study

of development?of development? comparative embryologycomparative embryology evolutionary embryologyevolutionary embryology teratologyteratology mathematical modelingmathematical modeling

Comparative EmbryologyComparative Embryology

Epigenesis Epigenesis versus versus preformationpreformation

Comparative EmbryologyComparative Embryology How does the concept of germ layers support epigenesis?How does the concept of germ layers support epigenesis? How does the concept of induction fit in here?How does the concept of induction fit in here?

Comparative EmbryologyComparative Embryology What principles did What principles did von Baer articulate von Baer articulate with respect to vertebratewith respect to vertebratedevelopment?development?

Comparative EmbryologyComparative Embryology General features of large group of animals General features of large group of animals

appear earlier than specialized features of appear earlier than specialized features of smaller groupsmaller group

Less general characteristics develop from Less general characteristics develop from more generalmore general

Comparative EmbryologyComparative Embryology A particular type of embryo, instead of passing A particular type of embryo, instead of passing

through adult stages of a lower form, departs through adult stages of a lower form, departs more and more from it.more and more from it.

Embryo of higher animal is only like early Embryo of higher animal is only like early embryo of lower animal.embryo of lower animal.

Comparative EmbryologyComparative Embryology How have fate maps How have fate maps

contributed to our contributed to our understanding of understanding of development?development?

Evolutionary EmbryologyEvolutionary Embryology How have observations of embryos contributed to our How have observations of embryos contributed to our

understanding of evolutionary relationships?understanding of evolutionary relationships?

Evolutionary EmbryologyEvolutionary Embryology Why is the distinction between analogous and Why is the distinction between analogous and homologous structures important?homologous structures important?

TeratologyTeratology

How are malformations different from disruptions?

Mathematical ModelingMathematical Modeling What’s the difference between isometric and What’s the difference between isometric and

allometric growth?allometric growth?

Figure 1.20(1) Figure 1.20(1) Reaction-diffusion Reaction-diffusion System of Pattern GenerationSystem of Pattern Generation

Figure 1.22 Figure 1.22 Pigment patterns of zebrafish Pigment patterns of zebrafish homozygous for the wild-type allele (A) and for three homozygous for the wild-type allele (A) and for three

different mutant alleles (B–D) of the leopard genedifferent mutant alleles (B–D) of the leopard gene