BIOL 215 Lecture Notes - Lecture 21: Circadian Rhythm, Devo, Louis Agassiz
1. Macroevolution – oct 10th
Tree of life – useful for origins, relationships, can build models from
it
Continuous change in Darwin`s evolution – slow, steady, progressing
changes continuing through time
Aristotle
One of the first to think about evolution
- Increasing levels of perfection (continuity)
- Ontogeny – recapitulates phylogeny
- First developmental biologist (chicken embryology – they look like
maggots!!)
- Plants -> animals -> man / vegetative -> sensitive -> rational soul
- Biology looked the same throughout most of the time
- Great Chain of Being / Scala Naturae
William Harvey
- 1651
- evolution is a term for development
- EPIGENESIS – atomistic but incorporated vitalistic explanations
Meckel-Serres
- Climax – Law of Terminal Addition 1700
- Develop literally from one to another
- Embryo = animals standing under it
Haeckel
- Series of embryos looking like sharks and chicks and pigs – bad
microscopy, much?
find more resources at oneclass.com
find more resources at oneclass.com
- First five stages of tree of life (monera, amoeba, sybamoeba,
planaea, gastrea – walled cells)
- Embryology (series) didn`t make much sense though – men
evolving from cows??
Von Baer
- Laws of Individual Development
- Looking at embryology
- Hierarchy of types
- Different stages of embryology
- Some animals share the same stages of embryology
- DIVISIONS by developmental symmetries and how the embryos
developed; Cuvier divided by embranchements (anatomical traits)
radiata, articulate, Mollusca, vertebrata
Fish phylogeny – Louis Agassiz
- Three-fold parallelism (diphycercal, homocercal, heterocercal)
- Lamprey – round tail
- Hybodontoidea – long tail sharky
- Spiny fish – longtail sharky
- Teleosts – symmetrical tail, looks circular in the inside fishy
HOW DO YOU GET FINS??
- Gegenbaur – fins come from gills?
- Thacher – side fold theory?
Both had good data, but was completely incomparable. Left the
field in disarray. Convinced people embryology wasn`t worth it
Thomson
- On growth and form
- New form to quantify variations of shape
find more resources at oneclass.com
find more resources at oneclass.com
