Evolutionary Evidence Part 5: Embryology

Objectives: I can define embryology. I can explain why it is an important piece of evolutionary evidence. I can analyze and evaluate embryos to determine common ancestry.

What is embryology? Embryology - branch of biology dealing with the development of the animal embryo

How is embryology an important part of evolutionary evidence? The homologous structures in an embryo suggest a common ancestor. The similarities among young embryos suggest evolution from a distant, common ancestor.

Section 15.1 Summary – pages 393-403 What is an embryo? An embryo is the earliest stage (pre-birth) of growth and development of both plants and animals. Embryos of different species have similar pharyngeal pouches and tails. Section 15.1 Summary – pages 393-403

What evidence of common ancestry can be determined from embryos? Vertebrate embryos exhibit homologous structures during certain phases of development but become totally different structures in the adult forms.

Section 15.1 Summary – pages 393-403 What evidence of common ancestry can be determined from embryos? Pharyngeal pouches Pharyngeal pouches Tail Tail Fish Reptile Bird Mammal Section 15.1 Summary – pages 393-403

Chicken Turtle Rat