1. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Prof. Stuart Bunt

2. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Humans are only one animal Much of our knowledge of the development of the brain comes from study of other animals Caenorhabditis elegans for cell lineages and genetics Drosophila for genetics Xenopus laevis for vertebrate embryology Zebra fish for vertebrate lineages Chick and quail for transplants/lineages Mouse and rat for mammalian development Fish and marsupials for regeneration of the CNS

3. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU We need to know their taxonomic relationships How closely related are their nervous systems? What characteristics are derived? What characteristics are convergent? What pre-adaptations are required? What restricts nervous system development in different phyla? Only evolution can make sense of taxonomic relationships Taxonomy is based on presumed evolution

4. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Nerve Nets Even primitive animals can have complex behaviour

5. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Hirudinea (Leeches) With the addition of a gut, cephalization and segmentation a segmental nerve pattern arises.

6. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Interneurons & Sensory Cells Added

7. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Segmentation Common in Invertebrates

8. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU

9. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Invertebrate Embryology is Determinate Individual cells can be identified Cells have specific lineages Destroy cells, specific parts of the embryo are missing Vertebrates are regulative (otherwise in vitro fertilization would be impossible)

10. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Invertebrate embryology is variable and quite unlike that of vertebrates

11. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Cephalopods Have the most complex nervous systems

12. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Invertebrate nervous systems are ventral Vertebrate nervous systems are dorsal Amphioxus Annelids

13. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Vertebrate Nervous Systems are Dorsal The inverted lobster!

14. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Hemichordates are a side issue?

15. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU We most likely evolved from tunicates Only echinoderms and vertebrates share caudal gastrulation Tunicates are sessile filter feeders Their larvae are mobile Some salps are permanently mobile Their tails have somites and a notocord Add a basic neural tube and you end up with Amphioxus.

16. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU All vertebrate embryos look very similar

17. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Primate evolution has been marked by an increase in cerebral volume by a rotation of the foramen magnum

18. Human Neurobiology 217 Prof Stuart Bunt SMBUNT@ANHB.UWA.EDU.AU Are Humans “Different”? Development of language needs many preadaptations? Use of hands and tools precede brain development Neanderthals had larger cranial capacity than Homo sapiens When did consciousness evolve? Is the brain more than just cells?