Lecture 22 Flashcards
1
Q
Primates
A
- Arboreal ancestor
- Grasping limbs with opposable thumbs
- forward- facing eyes (Depth perception, overlap btwn eyes is what causes 3D sight)
- Big cerebrum (encodes memory, higher functioning)
- Highly social (reduced brood size and extended parental care)
- Two major groups: (prosimians, anthropoids)
2
Q
Prosimians
A
- ex. lemurs, loris
- Not monkeys although they are primates
- mostly arboreal and nocturnal
- Once found on all continents, but now just Madagascar, SE Asia (no lemurs are found in Africa but some lorises are)
- Lemurs in Madagascar have radiated, not all found in trees and some are diurnal (Diurnal: awake during the day, opposite to nocturnal)
- Many species are threatened or endangered
3
Q
Anthropoids “the rest”
A
- Ex. Tarsier
among the smallest primates, only entirely carnivorous primate, large eyes that are heavier than their brain
4
Q
New World vs. Old World Monkeys
A
- New World: North and South America
- Old World: Africa and Asia
- Prehensile tail = tail used to grasp/hold objects (not present in Old World monkeys)
- New World monkeys also have flat noses and tend to be arboreal
5
Q
Gibbons, Orangutans and African Apes
A
- Lack tails
- Gibbons: smaller than other apes, mostly arboreal
- Orangutans: too large to cross from one tree to another by branches and mist go down to the ground and walk between them
- African apes (includes
6
Q
Old World Monkeys
A
long tailed macaques [Indonesia], baboon[South Africa], vervet [South Africa])
7
Q
New World Monkeys
A
(White-faced Capuchin, spider monkey, Howler monkey, vervet [introduced from the old world to the new world]
8
Q
Hominids
A
- Ardipithecus
- Australopithecus
9
Q
Ardipithecus
A
- In 2009, fossils of Ardipithicine ancestor uncovered dating back 4.4 million years ago (oldest)
- Fossils suggest it walked upright and didn’t use its arms for walking, as chimps do, yet it retains a primitive big toe that could grasp a tree like an ape
10
Q
Australopithecus
A
- Brains approx. 35% size of modern human brain
- Australopithecus afarensis
- Fully Bipedal
- “Lucy” 3.5 MYA from Ethiopia, most complete skeleton
- Provided evidence that bipedalism evolved before brains fully evolved
11
Q
Bipedalism
A
- walking on two legs
- Australopithecus
12
Q
Early Homo species
A
- Homo habilis “handy/skillful” (In Africa, 2.5-1.5 MYA, first tool use 2 MYA, shorter jaw, bigger brain)
- Homo erectus “standing” (Believe to be first hominid to leave Africa) (Spread to Eurasia) (1.6 MYA to 250,000 years ago, first fire use, as large as modern humans, but smaller brains, thick skull)
13
Q
Recent Homo species
A
Homo neanderthalensis
- discovered in Neander valley, Germany
- Coexisted with H. sapiens
- Disappeared approx. 30,000 years ago [possible due to extermination by H. sapiens]
- Short, stalky but powerful build
- brains larger than H. Sapiens
14
Q
Did H. Sapiens interbreed with Neanderthals?
A
- 1.5-2.1% DNA in non-Africans is estimated to be from Neanderthals
(0% in mitochondrion, found interbreed in nucleus)
15
Q
Did we interbreed with anyone else other than Neanderthals?
A
- 4-6% DNA in Melanesians is estimated to be from Denisovans
- Denisovans DNA is found only really in Melanesia and in Tibet where the genes were selected for because of high altitude living conditions (good to mate with neanderthals)
16
Q
Homo Floreisensis
A
- Found in Flores, Indonesia
- survived until 17,000 years ago
- Volcanic eruption likely caused its extinction
- Much smaller than present-day H. sapiens
17
Q
Homo Sapiens
A
- 0.2 MYA also arose in Africa
- spread out of Africa across Eurasia and to rest of world
- Larger brains than earlier Homo species, favoring increasingly complex social life
Neanderthals are very closed to us
18
Q
Mammalian Nervous System
A
- CNS
- PNS
- The brain
19
Q
Central Nervous System (CNS)
A
- brain and spinal cord
- Dorsal, hollow tube of nervous tissue (large cephalic ganglion [brain], long tube inferior to it [spinal cord], both brain and spinal cord protected by bone)
20
Q
Peripheral nervous system (PNS)
A
- System of lateral nerves
cranial nerved from brain, spinal nerves from the spinal cord
21
Q
Brain (4)
A
- Contains four distinct structures (cerebrum, cerebellum, diencephalon, brain stem)
22
Q
Cerebrum
A
- enlarged in primates (intellect, learning, memory, language, consciousness)
- divided into 2 hemispheres
- Top layer = cerebral cortex, rich in cell bodies (grooves and ridges, increasing surface area)
23
Q
Cortex
A
- Motor & sensory cortex
- amount of cortex devoted in various parts of the body
- Notes: lots of cortex devoted to mouth (talking, eating) and hands (tool use, fighting)
24
Q
Frontal lobe
A
- Phineas Gage - was stabbed through the brain by a rod when setting up dynamite (he survived but his personality changed)
25
Q
Temporal Lobe
A
- Facial recognition
- Tested monkey by showing him pictures of other monkeys to see if they could recognize it
26
Q
Limbic System
A
- include amygdala, Hippocampus & nucleus accumbens
- Responsible for basic physiological drives like hunger, thirst, emotions, long-term memory
- “pleasure and pain centres” located here
27
Q
Hippocampus
A
- spatial memory
- tested the brains of london taxi drivers vs. bus drivers (found taxi drivers had greater gray matter volume in the mid-posterior hippocampi (where spatial memory is stored) and less in the anterior hippocampi
28
Q
Amygdala
A
- “annoyance” of a sound is encoded in this part of the brain
