How do new adaptations arise Ontogeny and Evolution

1
How do new adaptations arise?Ontogeny and
Evolution

• What are the basic themes of development?
• How many genes change a structure?
• How do modules of developmental regulation
  contribute to diversity?

2
Early starfish development
3
Early stages of animal development
4
Fate maps of vertebrate embryos
5
Fate map of an invertebrate, Drosophila (blastula)
6
Stages of Drosophila development
7
Genes to phenotype black box
8
Modules in development I
9
Modules in development II
10
Modules in development III
11
Modules in development IV
12
Effects of homeotic mutations control of modules
13
Hoxc-6 expression in chick and snake
Thoracic rib development
Note repeated modules
14
Visualization techniques for Hox expression
Engrailed expression marks posterior of each
segment
Seven different Hox genes anterior to lower left
15
Hox gene expression in Drosophila
16
Segment-specific patterning functions of Hox
genes in the vertebrate hindbrain
17
Hox genes are everywhere!
18
Endomesoderm in Xenopus gastrula
19
The Distalless family genes influences outgrowths
onychophoran
annelid
butterfly
mouse
Sea urchin
tunicate
20
Pax6/eyeless genes are highly conserved in animal
eye development
Drosophila
Mus
21
Ectopic eye formation in Drosophila
22
Transcription factor, signaling proteins
23
Regulatory genes have multiple uses form networks
24
Cooption of basic parts builds new adaptations
25
Regulation of Ubx (not new genes) creates
patterns of epidermal cell hairs in the T3 leg of
3 Drosophila spp
26
A single gene directs adaptive pelvic fin
development of 3-spined sticklebacks
Long spines protect from fish predators repeated
evolution of loss in dragonfly-dominated habitats
with the same regulatory mutation
27
The tb1 gene underlies a major difference in
growth pattern between corn and teosinte
28
The ABC model of flower development