Exam Prep Flashcards
Obligate
By virtue of necessity; our recent ancestors of the past 2-3 million years had developed a number of adaptations that effectively obligate them to adopt a terrestrial, bipedal form of locomotion
Hominin
A term inclusive of modern humans and their bipedal ancestors
Facultative Bipedalism
Adopting a two-legged posture only under particular circumstances as an exception to a habitual non-bipedal form of locomotion
Canine Honing Complex
Sharpening, in this instance of one tooth through repeated contact with another
Diastema
A space between adjacent teeth in the dental row into which the canine from the opposite jaw fits in a closed mouth
Sectorial Premolar
P3 - found in Old World primates, a lower third Premolar in which the mesiobuccal surface appears as a long, sloping surface due to contact with the upper canine
Endocasts
Impressions of the inner surface of the cranium and the outer surface of the brain, which may occur naturally as “fossils” or from moulds created in the laboratory
Protohominin
Referring to a number of fossil for a sting between 4.5 and 6.5 mya that show some derived hominin features but also many panin-like or gorilline-like characteristics
Savannah Hypothesis
The now discredited idea that the development of open savannah grassland created conditions leading to the evolution of hominins
Where are Australopithecines found?
Found in East and South Africa
When are Australopithecines found?
Date from 4.2 - 1.1 mya
Evolutionary trends of Australopithecines
Canine reduction
Absence of canine honing complex
Retained some climbing ability
Later were obligate bipeds
Types of Australopithecines
Gracile and Robust
Gracile
Australopithecines that have anatomical evidence for retained climbing ability
Robust
Australopithecines genus Paranthropus, adopted a distinctive life way of hard-object feeding reflected in the megadont adaptation in dental an cranial features
Megadont
Literally, large teeth; these forms are characterized by expansion of the posterior teeth, i.e., premolars and molars
Gracile Species
A. anamensis A. afarensis Kenyanthropus platyops A. bahrelghazali A. africanus A. garhi A. sediba
Robust/Megadont Species
Paranthropus aethiopicus
Paranthropus boisei
Paranthropus robustus
Phylogeny
The evolutionary history of a group of organisms (timeline)
Stable Isotope
Different forms of an element that have different atomic mass and that are not radioactive
Insular Dwarfism
An evolutionary process that results from long-term isolation on a small island with limited food resources and a lack of predators - H. floresiensis
Linear Enamel Hypoplasia
Caused by childhood stress such as nutritional deficiencies, disease and environmental conditions. Forms in childhood when development of dental enamel is disrupted. It’s easy to see and permanent
Archaic Hominins
Emerge 500,000 ya
Found in Africa, Europe, and Asia
Combination of H. erectus and modern human traits
Relative increase in brain size and shape of skull
Out of Africa Model
Out of Africa model proposes that modern humans evolved from earlier arcahic populations in Africa sometime between 150,000 and 200,000 years ago, then spread to Europe and Asia, replacing pre-existing archaic populations with little or no interbreeding
Multiregional Evolution Model
The Multiregional evolution model preposes that archaic humans evolved into modern Homo sapiens in several regions of the Old World, with extensive gene flow between regions maintaining these populations as a single species
Assimilation Model
The assimilation model proposes that modern humans first evolved in Africa and spread from there to other parts of the Old World, where they interbred with local archaic populations, genetically swamping them
Race
In general biology, a category often considered synonymous with “subspecies,” into which individuals can be placed based on distinctive physiological, morphological, and/or ecological features; it is now generally held that the complexity of human biobehavioral variation cannot be usefully understood in terms of race
Monogenesis
The belief that all humans were created at once but that variation between populations reflected degeneration from the original form
Polygenesis
The belief that difference so called-races were created as separate species
Typology
A static perspective of the world ascribed to the philosopher Plato, in which “ideals” or “types” were perceived to be real, and variation as observed in the world was considered a deviation from ideal reality
