Lecture 22: Mammals 2 Flashcards
primates
- arboreal
- have grasping limbs
- have forward facing eyes
- have a big cerebrum
- VERY social
Two groups of primates
- Prosimians
2. Anthropoids
Prosimians
- once found everywhere, now just Madagascar and SE Aisa
- nocturnal
- many species endangered
ex. lemurs have radiated, not all are found in trees and some are diurnal and NOT found in Africa
Anthropoids
- smallest primates
- only entirely carnivorous primates
ex. TARSIER- big eyes, too large to rotate them
New World monkeys
- have prehensile tail (used to grip/grasp objects)
- have flat noses
- tend to be arboreal
Gibbons, orangutans and African apes
- have no tail
Gibbons
- smaller than other apes
- mostly arboreal
Orangutans
- too large to cross from one tree to another, so it goes down and walks
African Apes
- include gorillas, chimps and hominids
Hominids
- ardipithecus ansestor
- fossils uncovered that it walked upright
- didn’t use arms for walking
- retains a primitive big tow that could grasp tree like an ape
Australopithecus
- 35% brain size compared to humans
- “Lucy”- fossil had a complete skeleton. Provided evidence that bipedalism evolved before brains fully developed
Early Homo species
• Homo Habilis - handy/skillful - shorter jaw, bigger brain • Homo erectus - standning - first fire use - as large as modern humans (small brain, TICK skull)
Recent Homo species
•Homo Neanderthalensis
- coexisted with H.sapiens (possibly exterminated by them)
- short & stalky, but powerfully built
- larger brains than humans
• HOMO SAPIENS THE MOST POWERFUL SPECIES OF ALL TIME!!!!!1!11!!!!!1
- arose in Africa, then spread out
- larger brains that earlier homo species
- favouring increasingly complex social life
Did Homo sapiens interbreed with Neanderthals? DID THEY GET THAT N DICK?!
- 1.5-2.1% of DNA from non-africans is from Neanderthals
* therefore, they spread out from Africa and started interbreeding*
Homo Floresiensis
- another species that coexisted with homo sapiens
- half out height (like a hobbit)
- extinction due to volcanic eruption
- survived until 17,000 YA
Central nervous system
- dorsal hollow tube of nervous tissue
- large, cephalic ganglion (brain)
- long tube inferior to it (spinal cord)
- protected by bone
Peripheral nervous system
- system of lateral nerves
- cranial nerves from brain
- spinal nerves from spinal cord
Structures in brain
- Cerebrum: conscious thought and memory
- Diencephalon: info relay and control of homeostasis
- Brain stem: info relay and autonomic control
- Cerebellum: coordination complex of complex motor patterns
Cerebrum
- enlarged in primates
- used for intellect, memory, language and consciousness
- left side of brain communicates with right side of bodu
The frontal lobe
personality
Temporal lobe
helps with facial recognition
- neuron responds maximally to a complete face shown
Amyglada
- encodes for both acoustic features pf stimulus and its perceived unpleasantness
Hippocampus
- has to do with memory
Limbic system
- responsible for basic physiological drives (hunger, thirst, emotions, long term memory)
