Archaeology & Evolution Glossary (A)



abduction: Movement of a limb away from the body’s midline, or of a digit away from the long axis of a limb.

aboriginal: Native, aboriginal.

absolute dating: Age estimation in calendar years before the present; also known as numerical dating, chronometric dating.

acetabulo-cristal buttress: A bony buttress extending vertically down the iliac blade, supporting it against the powerful muscular forces generated by the hip abductor muscles.

acetabulum: Joint depression in the os coxa into which the head of the femur fits, the socket in the ball-in-socket hip joint. The three bones of the os coxa (ilium, ischium, pubis) meet in the acetabulum.

achieved status: Social standing and prestige reflecting the ability of an individual to acquire an established position in society as a result of individual accomplishments.

acrocentric chromosome: A chromosome with a centromere near the end such that it has one long arm plus a stalk and a satellite.

adaptation: Changing to fit, or respond to, the requirements of the environment.

adaptive radiation: Multiplication of species from a single phyletic line into a series of closely related taxa occupying different niches or adaptive zones.

adaptive valleys (cf. adaptive peaks): Stable morphological configurations based on effective genetic compromises that maximize overall fitness in specific adaptive niches, envisioned as a series of dips across a fitness plateau.

additive genetic variance (VA): Genetic variance that arises from the additive effects of genes on the phenotype.

adduction: Movement of a body’s limb towards the midline, or of a digit toward the long axis of a limb.

adenine (A): A purine base found in RNA and DNA; in double-stranded DNA adenine pairs with the pyrimidine thymine.

affine: A relative by marriage.

affinity: Relationship by marriage. May include the relationship between corporate groups linked by marriage between their members.

agnate: A person related by patrilineal descent.

airorhynchy: An upward rotation of the front of the palate (the alveolar portion of the face under the nose).

allele: One or two or more alternative forms of a single gene locus. Different alleles of a gene each have a unique nucleotide sequence, and their activities are all concerned with the same biochemical and developmental process, although their individual phenotypes may differ.

allele frequency: The percentage of an allele at a particular locus relative to all the different alleles at the locus, usually calculated for a population.

allelomorph: A term coined by William Bateson; literally means “alternative form”; later shortened by others to allele.

Allen’s Rule: To retain heat, warm-blooded animals tend to have shorter and bulkier limbs in colder climates than their relatives in warmer regions.

alliance: A system whereby descent groups or other kin groups or other kin groups are linked by a rule or prescriptive or recurrent marriage so that the groups remain in an affinal relationship to one another across generations.

allometry (allometric scaling): Generally, the effect of size on shape. Specifically, any relationship of anatomical variables that fits the equation Y = AXk (A is a constant, the exponent k the coefficient of allometry).

allopatric speciation: Species formation when there is geographical isolation (cf. sympatric speciation).

allopatry: Non-overlapping geographic ranges.

allopolyploidy: Polyploidy involving two or more genetically distinct sets of chromosomes.

alternation of generations: The two distinct reproductive phases of green plants in which stages alternate between haploid cells and diploid cells (gametophyte cells and sporophyte cells).

altricial: Having the young born in an immature and helpless condition.

altruism: Behavior that benefits another individual at a cost to the actor, where cost and benefit are defined in terms of reproductive success.

alveolar height: The vertical dimension of the lower part of the skeletal face, from the lower nasal border to the bone between the upper incisors.

alveolar margin: The rim of the alveolar process.

alveolar process: The tooth-bearing portion of the jaw.

alveolar prognathism: Forward projection of the portions of the jaws that hold the teeth and their roots.

alveolus: Socket, as in tooth socket.

Ames test: A test developed by Bruce Ames in the early 1970s that investigates new or old environmental chemicals for carcinogenic effects. It uses the bacterium Salmonella typhimurium as a test organism for mutagenicity of compounds.

amino acids: The building blocks of polypeptides. There are 20 different amino acids.

amino-acid racemization: A method used in the dating of both human and animal bone. Its special significance is that with a small sample (10g) it can be applied to material up to 100,000 years old, i.e. beyond the time range of radiocarbon dating.

aminoacyl-tRNA: A tRNA molecule covalently bound to an amino acid. This complex brings the amino acid to the ribosome so that it can be used in polypeptide synthesis.

aminoacyl-tRNA synthetase: An enzyme that catalyzes the addition of a specific amino acid to a tRNA molecule. Since there are 20 amino acids, there are also 20 synthetases.

amniocentesis: A procedure in which a sample of amniotic sac fluid is withdrawn from the amniotic sac of a developing fetus and cells are cultured and examined for chromosomal abnormalities.

anagenesis: Anatomical change in a single lineage over time that is sufficient to name a new species.

analysis of variance (ANOVA): A series of statistical procedures for examining differences in means and for partitioning variance.

anaphase: The stage in mitosis or meiosis during which the sister chromatids (mitosis) or homologous chromosomes (meiosis) separate and migrate toward the opposite poles of the cell.

anaphase II: The second stage of meiosis during which the centromeres (and therefore the chromatids) are pulled to the opposite poles of the spindle. The separated chromatids are now referred to as chromosomes in their own right.

anatomical equivalence: The same requirements met in different ways.

andesite: A fine-grained igneous rock in the diorite family that is intermediate in color between the light end of the spectrum (rhyolite) and the dark end of the spectrum (basalt).

aneuploidy: The abnormal condition in which one or more whole chromosomes of a normal set of chromosomes either are missing or are present in more than the usual number of copies. Aneuploidy also refers to the abnormal condition in which a part or parts of a chromosome or chromosomes are duplicated or deleted.

angular torus: A raised and thickened ridge at the back of the posterior temporalis muscle attachment, where the line marking the furthest backward extent of its fan-shaped fibers angles downward and forward.

angular trigone: A backward-facing triangular form to the lateral-most part of the supraorbital torus. The apex is created by a prominent temporal ridge, and the torus is thicker at the trigone than it is more medially. To be distinguished from frontal trigone.

anterior: Frontal portion.

anterior iliac spines: In hominids, two bony projections (superior and inferior) for muscles to attach that extend the leg, protruding from the front edge of the ilium. Sartorius attaches on the anterior iliac spine and rectus femoris (one of the quadriceps) on the anterior inferior spine.

anterior pillars (of the maxilla): Two vertical columns of bone, on either side of the nasal aperture, extending above and lengthening the pilaster of bone surrounding the canine roots.

anterior tooth loading: Forces placed on the front teeth when an object is held between them. The source of the force on the teeth of each jaw is the opposite jaw and the force applied to the object.

anthropithecine: A member of the subfamily Anthropithecinae, the group including the African apes and the hominids.

anthropology: The study of humanity – our physical characteristics as animals, and our non-biological characteristics collectively referred to as culture. The subject is traditionally broken down into four sub-disciplines: biological (physical) anthropology, cultural (social) anthropology, archaeology, and linguistics.

antibody: A protein molecule that recognizes and binds to a foreign substance introduced into the organism.

anticodon: A three-nucleotide sequence that pairs with a codon in mRNA by complementary base pairing.

antigen: Any large molecule that stimulates the production of specific antibodies or that binds specifically to an antibody.

antimeres: Equivalent teeth from opposite-sides of the jaw (i.e., as in left and right M1).

apes: The large hominoid arboreal primates, based on similarity and not common descent (apes are not a monophyletic group).

apical: Toward or at the far end.

apical ancestor (ancestress): The ancestor or ancestress from which descent is traced (the “apex” of the triangle of descendants).

apomorphy: A derived character, a feature whose state is unlike the ancestral condition. If it is a unique variation it is an autapomorphy, if shared by more than one taxon, it is a synapomorphy.

appendicular skeleton: The bones of the limbs and the shoulder girdle.

applied research: Research done with an eye towards making products that can be commercialized, or at least made available to humankind for practical benefit.

arboreal: Living mainly in trees; for instance, arboreal quadrupeds are animals that use all four limbs in walking and running on trees limbs.

Arboreal theory: A theory that many of the cranial and post-cranial adaptations found in primates are actually exaptations for life in the trees.

archaeobotany: See paleoethnobotany.

archaeological culture: A constantly recurring assemblage of artifacts assumed to be representative of a particular set of behavioral activities carried out at a particular place and time.

archaeological sequence: Regular stratigraphic variation within a deposit reflecting the appearance of new tool types, changes in toolmaking technologies, or changing frequencies of tools.

archaeology: A subdiscipline of anthropology involving the study of the human past through its material remains.

archaeology of cult: The study of the material indications of patterned actions undertaken in response to religious beliefs.

archaeozoology: Sometimes referred to as zooarchaeology, this involves the identification and analysis of faunal species from archaeological sites, as an aid to the reconstruction of human diets and to the understanding of the contemporary environment at the time of deposition.

archaic: Ancient.

articular eminence: The articular surface is in front of the mandibular fossa, where the mandibular condyle is located when it transmits force during mastication. The eminence may be expressed as anything from a straight, angled, plane to vertical and horizontal surfaces that meet along an edge. The back side of the eminence is the front side of the fossa.

articular surface: Portion of a bone that is linked to another bone through an intervening joint of cartilage.

articulation: Joint between two or more bones.

artifacts: Humanly modified objects.

artificial selection: Human determination as to which individuals will survive and reproduce. If the selected traits have a genetic basis, they will change and evolve.

ascending ramus: Vertical portion of the mandible, extending from the corpus to the condyle.

ascribed status: Social standing or prestige which is the result of inheritance or hereditary factors.

asexual (vegetative) reproduction: Reproduction in which a new individual develops either from a single cell or from a group of cells in the absence of any sexual process.

assemblage: All the artifacts, fauna, and other debris found in a single layer or excavation unit at a side.


association area: One of the many regions of the cerebral cortex not devoted exclusively to either primary sensory perception such as vision and audition, or to motor movement, but rather to more complex association between these modalities. There are frontal, parietal, and temporal association areas.

asterion (ast): A point on the back of the skull at which the lambdoidal, parietomastoid, and occipital sutures meet.

asterionic notch: The notch at the bottom-rear of the parietal bone, located over the mastoid process.

astragalus (talus): Ankle bone.

asymmetrical alliance: In alliance theory, a marriage system involving indirect exchange.

atlas: Most superior of the cervical vertebrae, supporting the cranial articulation.

atomic absorption spectrometry (AAS): A method of analyzing artifact composition similar to optical emission spectrometry (OES) in that it measures energy in the form of visible light waves. It is capable of measuring up to 40 different elements with an accuracy to approximately one percent.

attentuation: A regulatory mechanism in certain bacterial biosynthetic operons that controls gene expression by causing RNA polymerase to terminate transcription.

attribute: A minimal characteristic of an artifact such that it cannot be further subdivided; attributes commonly studied include aspects of form, style, decoration, color, and raw material.

attritional age profile: A mortality pattern based on bone or tooth wear which is characterized by an overrepresentation of young and old animals in relation to their numbers in live populations. It suggests either scavenging of attritional mortality victims (i.e. those dying from natural causes or from non-human predation) or the hunting by humans or other predators of the most vulnerable individuals.

auditory meatus: External opening of the ear canal.

auditory tube: The tube of the bone holding the tympanic part of the temporal, the passage leading to the tympanic membrane.

auricular point (au): A point often used for measurements, particularly projected into the sagittal plane, located vertically above the center of the auditory meatus and porion, on the root or base of the zygomatic arches. This point is located a few millimeters above, and lateral to, the porion.

australopithecine: Referring to members of the genus Australopithecus.

Australopithecus: A collective name for the earliest known hominids emerging about 5 million years ago in East Africa.

autapomorphy: An apomorphy unique to a single species.

autonomously replicating sequences (ARS elements): Specific sequences (e.g., in baker’s yeast, Saccharomyces cerevisiae) that, when included as part of an extrachromosomal, circular DNA molecule, confer on that molecule the ability to replicate autonomously.

autopolyploidy: Polyploidy involving more than two chromosome sets of the same species.

autosome: A chromosome other than a sex chromosome.

auxotroph: A mutant strain of a given organism that is unable to synthesize a molecule required for growth and therefore must have that molecule supplied in the growth medium in order for it to grow.

auxotrophic mutation: A mutation that affects an organism’s ability to make a particular molecule essential for growth.

avunculocal: Postmarital residence of a person with their mother’s brother.

axial skeleton: The part of the skeleton along the central axis of the body: vertebral column, pelvis, and thorax.

axillary: Of or pertaining to the armpit.

axion: The nerve fiber extending away from the nerve cell body to meet the axion of another nerve cell.


Andrefsky, W., Jr. 1998. Lithics: Macroscopic Approaches to Analysis. Cambridge: Cambridge University Press.
Keesing, R.M. 1975. Kin Groups and Social Structure. Fort Worth: Harcourt Brace.
Renfrew, C., and P. Bahn. 1996. Archaeology: Theories, Methods, and Practice. New York: Thames and Hudson Inc.
Russell, P.J. 1998. Genetics. Menlo Park: Addison Wesley Longman, Inc.
Wolpoff, M. 1999. Paleoanthropology. second edition. Boston: McGraw-Hill.