Human Evolution Flashcards
Hominid
Any member of the group consisting of all modern + extinct humans and great apes
Classify
Arrange a group of people in classes or categories according to shared qualities or characteristics
Taxonomy
A hierachiacl system for classifying and identifying organisms
Species
Only organisms in the same species can produce fertile offspring - presumes you are in the same genus
Hominid Evolutionary trends
Directional change in a character state, or set of character states resulting in a significant change through time
Evolutionary trends examples
- Relative size of cerebral cortex
- Mobility of the digits
- Prognathism + dentition
- Locomotion - Adaps to bipedalism + quadrupedalism
Relative size opf cerebral cortex
Cerebrum responsible for complex functions - vison, memory, reasoning + malipulative ability. Larger the cortex more accurate visual + tactile perception
Number of cerebral convolutions increased
Permits greater surface area of cortex - effects on development.
Relative size of cerebral cortex
Average increase in cerebrum in particular the cerebral cortex - frontal lobe
Mobility of digits
Primates are pentadactyl (5 digits per limb). Hihg mobile due to arboreal - living in ttrees.
Evolutionary trends - digits
Increasing ability to mnove digits independantly of one another - most evolved = thumb - independent and opposable.
Power Grip
Is carrying or grasping task where fingers flex towards palm - most forceful grip
Precision Grip
Object pinched between thumb and fingers - fine motor skills
HUman Lacking opposable big toe
Dont live in trees, no need to grip branches - uses to balance
Prognathism
Projecting lower jar or chin. Human jaw is smaller than apes - better centre of gravity
Dentition
Dental arch - Humans are parabolic + teeth are similar in height. Apes have parllel sides + large canine teeth.
Dentition trend
Towards smaller more uniform teeth and more rounded parabolic shape