Describe the hypothesis of the paper (Why limblessness and thoracic…
Describe the hypothesis of the paper
Why limblessness and thoracic elongation in snakes?
what is the developmental basis for limblessness ?
Other Questions? or comments
No limbs, large number of identical vertebrate
Most recently evolved
Tinkering with the same set of genes
Have snakes evolved from lizards?
Natural selection takes a really long time to act (gradual)
Enough time needs to account for the change to take place
Maybe this isn't right. some can happen rapidly (another ex is polyploidy in one generation)
Should we reevaluate the idea of evolution?
What is evo-devo?
Evolution and development
The union of embryology and evolutionary studies (think dog paper eek!)
Ecological burrowing niches?
Sonic hedgehog gene
What methods were used?
Morphological stained embryos
Scanning electron microscope
What caused such a great morphological change?
Hox genes (3)
What sources of evolutionary novelties are there?
Genetic toolkit for creating limb variation
Explore other habitats, meet other niches
Does limblessness seem to be beneficial? (Think: Has it only evolved once?)
Why are there none today if it's so beneficial? Why do we have limbs if they're no good????
It has evolved many times
Underlying development changes lead to huge morphological change
How will understanding the developmental anatomy of limbless organisms help anything?
Understanding the future
Understanding the past and evolution
What is the morphological change?
What is the developmental change?
Hox genes and apical ridge