User:Mateuszica/Timeline of brain evolution
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http://en.wikipedia.org/wiki/User:Mateuszica/Timeline_of_brain_evolution/entulho
Contents |
[edit] pre-brain era
600 Ma
Following sponges, Cnidaria (jellyfish, etc.), Ctenophora, and other multicellular animals appear in the oceans. Cnidaria and Ctenophora are some of the earliest creatures to have neurons, in the form of a simple net, with no central nervous system.
Flatworms (Platyhelminthes), the earliest animals to have a rudimentary brain .
--- Impulses to these nerve cells are sent from nerve rings that have collected information from the environment of the jellyfish
echinoderm
They have a simple radial nervous system that consists of a modified nerve net (interconnected neurons with no central organs); nerve rings with radiating nerves around the mouth extending into each arm; the branches of these nerves coordinate the movements of the animal. No echinoderms has a brain, some however do have ganglia.
hydra
Nerve nets connect sensory photoreceptors and touch sensitive nerve cells that are found in the body wall and tentacles of hydras.
cnidaria
Their movement is coordinated by a decentralized nerve net and simple receptors.
ver -- http://en.wikipedia.org/wiki/Cnidaria#Body
[edit] early brain era
antes vertebrates e insetos
[edit] fish era
cartilgem e fish
[edit] amphibina era
see : Nerve net
365 Ma | Primitive tetrapods developed from a fish with a two-lobed brain in a flattened skull, . The "living fossil" coelacanth brain like????. Amphibians today still retain many of the brain ????? characteristics of the early tetrapods.
[edit] amphibina era
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[edit] reptile era
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[edit] mammal era
220 Ma
| the earlist Mammals appear around this time and with them the Neocortex also evolve. This brain region is unique to mammals.
[edit] primate era
25 Ma
| Proconsul slightly larger brain relative to body size.
[edit] homo era
2 Ma
| Homo habilis (handy man) uses primitive stone tools (choppers) in Tanzania. . Emergence of Broca's area (speech region of modern human brain).
1.75 Ma
| Dmanisi man/Homo georgicus , tiny brain came from Africa, with Homo erectus and Homo habilis characteristics.
1.8 Ma | Homo erectus would bear a striking resemblance to modern humans, but had a brain about 74 percent of the size of modern man. Its forehead is less sloping
355 kYA | Homo heidelbergensis had a larger brain-case, about 93% the size of that of Homo sapiens.
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