11A: Classification and Characteristics of Modern Humans Flashcards
Taxonomy
The process of identifying naming and grouping organisms
Homologous structures
A structure within a group of species that performs a different function yet has the same underlying structure
Molecular Phylogeny
Comparison of nucleotide sequences of genes and amino acid sequences of proteins, from which evolutionary relationships can be inferred
Primate
The order consisting of all current and extinct Humans apes and monkeys, characterised by having dextrous hands with opposable thumbs and a relatively large and developed brain
Hominoid
The superfamily consisting of all current and extinct humans and apes
Hominin
The subfamily consisting of all current and extinct bipedal primates
Bipedal
Able to work on two legs, or upright
Genus
A group of related organisms that share a recent common ancestor
Species
A group of organisms that can interbreed, producing fertile and viable offspring
Features of mammals
Bear Live young
Produce milk
Have fur/hair
Features of primates
Dextrous/grasping hands
opposable thumbs
Forward facing eyes
Features of Hominoids
No tail
Molars with 5 cusps (not 4)
Broad and flattened ribcage
Features of hominins
Bipedal, which separates humans from other great apes
main characteristics in the evolution of hominin skulls
More centralised foreman magnum
Smaller brow ridge
More Parabolic Jaw
Flatter Face
Two main overall characteristics in the evolution of hominins
Change in limb structure
Increase in brain size
Timeline of Australopithecus
4.4-1.4 Million years ago
Timeline of Homo
1.4 mya - current
Bipedalism
The characteristic of being bipedal, i.e walking upright on two legs
Foramen Magnum
Hole in the base of the skull through which the spinal cord enters/exits the skull
Adaptations to support bipedal locomotion
Increase in arm to leg ratio
Greater Femur angle
Big toe aligned with rest of toes
Increase arch and heel size
Advantages of bipedalism
Helps keep the body cool
Frees hands
Standing taller allows observation for food water or potential predators
4 key regions of hominin brain in development
Occupital lobe
Cerebral cortex
Broca’s area
Cerebellum
Occupital Lobe
Significance of this region
Increased vision of greater distances
Cerebral cortex
Significance of this region
Processing of visual information
Depth of planning
Memory
Problem solving and reasoning
Broca’s Area
Significance of this region
Language/speech
Cerebellum
Significance of this region
Fine movements and sensations (particularly fingers)
