Archaeology & Evolution Glossary (M)

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


 
macrocrystalline: The texture of a rock with grains or crystals easily observed with the naked eye or over 0.75 mm in diameter.

macroevolution: Evolution above the species level; the evolution of higher taxa and the processes that result from differences in species survivorship or rates of speciation.

macrofamily: Classificatory term in linguistics, referring to a group of language families showing sufficient similarities to suggest that their speakers are genetically related.

macromolecule: A large molecule (such as DNA, RNA, and proteins) that has a molecular weight of at least a few thousand daltons.

mafic rock: Refers to igneous rock dark in color as a result of dark minerals such as olivine and pyroxene.

magma: Molten rock that cools and solidifies below the surface of the earth.

magnetic reversal: Alteration of the earth’s magnetic field so that its polarity is reversed.

malar: See zygomatic.

malar incisive (notch): See maxillary notch.

mammelon: Small elevations found along the occlusal margin or newly erupted incisor.

mandible: Lower jaw.

mandibular corpus (body): Horizontal or tooth-bearing portion of the mandible.

mandibular foramen: Opening on the internal surface of the ramus for the mandibular vessels and nerves to pass. There are two distinct anatomies to its rim. In the common form the rim is “V” shaped, with a groove separating the anterior and posterior parts. In the horizontal-oval form there is no groove, and the rim is horizontally oriented and oval in shape, the anterior and posterior parts connected.

mandibular (glenoid) fossa: Joint for the mandibular articulation with the skull, a depression on the base of the temporal bone, just in front of the ear opening, into which the mandibular condyles fit.

mandibular groove: A groove extending down from the lower rim of the mandibular foramen or from just below it.

mandibular ramus: See ascending ramus.

mandibular symphysis: The midline joining plane, connecting the two sides of the mandible, fused in adult Anthropoidea.

mandibular (transverse) torus: Shelf-like thickening of bone on the inside of the mandibular symphysis; superior and inferior transverse tori can be present but there can also only be one. The inferior transverse torus is a simian shelf if it is thin and projects so far to the rear that its lowest point is also its most posterior.

mandibular (symphyseal) trigone: An upward facing triangular form at the base on the symphysis.

manuport: An unmodified piece of rock known to be carried to a locality by a hominid because it could not have gotten there naturally.

mapping functions: Mathematical formulas that are used to correct the observed recombination values for the incidence of multiple crossovers.

map unit (mu): A unit of measurement used for the distance between two gene pairs on a genetic map. A crossover frequency of 1 percent between two genes equals 1 map unit. See also centi-Morgan.

marginal ridges: Elevated ledge on the edges on the inner surface of the incisors.

market exchange: A mode of exchange which implies both a specific location for transactions and the sort of social relations where bargaining can occur. It usually involves a system of pricemaking through negotiation.

masseter muscle: A short, quadrangular muscle between the zygomatic arch and the lower edge of the jaw, along its outside, supplying bite power.

mastication: Chewing.

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

mastoid process: A pyramid-shaped prominence of cancelous bone on the temporal bone behind the external auditory meatus. Muscles that extend and turn the head attach on it.

mastoid tubercle: A distinct bump on the lateral face of the mastoid process, just behind the external auditory meatus. It is usually treated as a nonmetric trait.

mate recognition system: The system of signals (chemical, olfactory, vocal, visual) that bring together potential breeding partners.

material culture: The buildings, tools, and other artifacts that constitute the material remains of former societies.

maternal effect: The phenotype in an individual that is established by the maternal nuclear genome, as the result of mRNA and/or proteins that are deposited in the oocyte prior to fertilization. These inclusions direct early development in the embryo.

maternal inheritance: A phenomenon in which the mother’s phenotype is expressed exclusively.

mating types: A genic system in which two sexes are morphologically indistinguishable but carry different alleles an will mate.

matrifocal: Family or other group headed by a female.

matrilateral: Based on relationship on the mother’s side.

matrilineage: See lineage.

matrilineal: Descent reckoned through the female line.

matrilocal: See uxorilocal.

matrix: The physical material within which artifacts are embedded or supported.

Maxam-Gilbert sequencing: A method of rapid sequencing of DNA molecules developed by Allan Maxam and Walter Gilbert. The technique uses specific chemical reactions to break DNA at specific nucleotides. The DNA is first radiolabeled with 32P at the 5′ or 3′ end of a chain. Second, the DNA is chemically modified and cleaved at various points along the backbone. Third, the DNA fragments are analyzed with polyacrylamide gel electrophoresis.

maxilla: Paired bone of the upper jaw, enclosing the nose and the inner and lower rims of the eye and holding the upper teeth.

maxillary notch (incisura malaris): A distinct angle between the lower border of the cheek at the zygomatic process of the maxilla and the external palate wall, which establishes a notched lower cheek contour.

maxillary pillar eversion: Expansion and outward projection of the frontal process of the maxillary bones, the part of the maxilla that joins the frontal and supports the nasal bones along the inside of the orbits.

maxillary shelving: A straight lower cheek border that merges smoothly into the lateral wall of the palate and creates a continuous bone mass between the masseter attachment and tooth row.

maxillary sinus: Air space within the maxillary bone, under the lower surface of the orbits and above the tooth roots.

maximum frontal breadth: See frontal breadth.

mean: The average of a set of numbers, calculated by adding all the values represented and dividing by the number of values.

meatus: A tube-like passageway.

medial: Toward the midline of the body.

medullary cavity: The hollow or marrow-filled center of long bones.

megadont: Having large teeth (usually large postcanine teeth).

megafauna: Very large animals, such as elephants, mammoths, or giant sloth.

megasporogenesis: The formation in flowering plants of megaspores and the production of the embryo sac (the female gametophyte).

meiosis: Two successive nuclear divisions of a diploid nucleus that result in the formation of haploid gametes or of meiospores having one-half the genetic material of the original cell.

meiosis I: The first meiotic division that results in the reduction of the number of chromosomes. This division consists of four stages: prophase I, metaphase I, anaphase I, and telophase I.

meiosis II: The second meiotic division, resulting in the separation of chromatids.

member: In geology, a subdivision of a rock formation.

menarche: Onset of menstruation, marked by the first menstrual period.

Mendelian factor: See gene.

Mendelian population: An interbreeding group of individuals sharing a common gene pool; the basic unit of study in population genetics.

mental eminence: Projecting mandibular trigone, or chin.

mental foramen: A large, sometimes multiple, foramen on the lateral anterior surface of the mandibular corpus, for the mantal nerve and vessels.

mesial: The side of the tooth nearest the midline of the jaw, as directed along the tooth row.

mesial drift: Movement of the teeth slowly toward the front of the mouth as the distance between adjacent teeth decreases with interproximal wear.

mesiodistal: Front to back direction, as taken along the tooth row arch, the length of the tooth.

mesocephalic: Describes an intermediate Cephalic Index, between brachycephalic and dolichocephalic.

Mesolithic: An Old World chronological period beginning around 10,000 years ago, situated between the Paleolithic and Neolithic, and associated with the rise to dominance of microliths.

messenger RNA (mRNA): The RNA molecule that contains the coded information for the amino acid sequence of a protein.

metabolism: The internal processes that make energy available.

metacarpals: Five parallel bones of the hand connecting the phalanges (fingerbones) with the carpals (bones of the wrist).

metacentric chromosome: A chromosome that has the centromere approximately in the center of the chromosome.

metamorphic rock: Rock formed or changed either structurally or mineralogically by heat and pressure underground.

metamorphosed: Usually refers to rocks that have been changed by heat and pressure.

metaphase: A stage in mitosis or meiosis in which chromosomes become aligned along the equatorial plane of the spindle.

metaphase II: The second stage of meiosis during which the centromeres line up on the equator of the second-division spindles (in each of two daughter cells formed from meiosis I).

metaphase plate: The plane where the chromosomes become aligned during metaphase.

metaquartzite: A quartzite of metamorphic origin as opposed to a sedimentary origin. The quartz grains in metaquartzite are usually deformed and fused from heat and pressure.

metastasis: The spreading of malignant tumor cells throughout the body so that tumors develop at new sites.

metatarsals: Five parallel bones of the foot connecting the phalanges (toe bones) with the tarsal bones (bones of the arch).

methodological individualism: Approach to the study of societies which assumes that thoughts and decisions do have agency, and that actions and shared institutions can be interpreted as the products of the decisions and actions of individuals.

metopic suture: Midline suture joint between the two sides of the frontal bone, an uncommon variation in adults.

microblade: A bladelet or small blade. This term is usually associated with bladelets found in the Arctic areas of North America and northeastern Asia.

microcystalline: Describes a rock in which the individual crustals can only be seen as such under a microscope.

microevolution: Evolution of populations over short periods of time, in response to observable causes.

microfauna: Very small animals, such as bats, moles, or mice.

microhabitat: The immediate environment surrounding an organism.

microliths: Very small blades usually geometric in form used in composite (hafted) tools.

microsporogensis: The formation in flowering plants of microspores in the anthers and the production of the male gametophyte (pollen), normally from diploid microsporocytes.

microwear: The traces of wear on stone tools that is not visible without magnification. Such wear may be in the form of a retouch or polish.

microwear analysis: The study of the patterns of wear or damage on the edge of stone tools, which provides valuable information on the way in which the tool was used.

midden: A deposit of occupation debris, rubbish, or other byproducts of human activities.

Middle Range Theory: A conceptual framework linking raw archaeological data with higher-level generalizations and conclusions about the past which can be derived from this evidence.

midface: The central portion of the face, comprised mainly of the cheeks and nose.

midsex average: The mean value of a characteristic, estimated as though there were an equal number of males and females, calculated by taking the average of the male mean and the female mean.

migration (genic): The movements of genes caused by individuals moving, including new individuals entering (immigration) or leaving (emmigration) a population, introducing or removing genetic material and thereby changing allele frequencies.

milk teeth: See deciduous teeth.

minimum frontal breadth: See postorbital breadth.

missense mutation: A gene mutation in which a base-pair change in the DNA causes a change in an mRNA codon, with the result that a different amino acid is inserted into the polypeptide in place of one specified by the wild-type codon.

mitochondria: The small extra-nuclear organelles (bodies) within a cell’s cytoplasm that control production of energy from food through the production of ATP (adenosine triphosphate).

mitochondrial DNA (mtDNA): The single (double stranded) DNA molecule that controls the development and functioning of the mitochondrion containing it. Because reproduction is by cloning, mtDNA is usually passed along female lines, as part of the egg’s cytoplasm.

mitosis: The process of nuclear division in haploid or diploid cells producing daughter nuclei that contain identical chromosome complements and that are genetically identical to one another and to the parent nucleus from which they arose.

mitotic crossing-over (mitotic recombination): A genetic recombination that occurs following the rare pairing of homologs during mitosis of a diploid cell.

MNI (minimum number of individuals): A method of assessing species abundance in faunal assemblages based on a calculation of the smallest number of animals necessary to account for all the identified bones. Usually calculated from the most abundant bone or tooth from either the left or right side of the animal.

mobility art: A term used for the portable art of the Ice Age, comprising engravings and carvings on small objects of stone, antler, bone, and ivory.

moderately repetitive sequence: A DNA sequence that is reiterated from a few to as many as 103 to 105 times in the genome.

moiety: A division of a society into two social categories or groups, characteristically by a rule of patrilineal descent (patri-moiety) or matrilineal descent (matrimoiety).

molar: A flat posterior tooth.

molariform: Molar-like in form and function; for instance, a premolar adding cusps and becoming more closely rectangular in outline.

molecular clock: A means of determining dates of evolutionary divergences using genetic similarities between extant species and assuming that molecular evolution proceeds at a constant rate.

molecular genetics: A subdivision of the science of genetics involving how genetic information is encoded within the DNA and how biochemical processes of the cell translate the genetic information into the phenotype.

moment (if inertia): The effect of the distribution of the mass of an object on its resistance to change in motion. A moment is calculated by multiplying the magnitude of a force by the length of its lever arm, the perpendicular distance between the line of action of the force and the point where it is applied.

monocausal explanation: Explanations of culture change (e.g. for state origins) which lays stress on a single dominant explanatory factor or “prime mover.”

monoecious: A term referring to plants in which male and female gametes are produced in the same individual.

monogamy: A social system based on mated pairs and their offspring.

monohybrid cross: A cross between two individuals that are both heterozygous for the same pair of alleles (e.g., Aa x Aa). By extension, the term also refers to crosses involving the purebreeding parents that differ with respect to the alleles of one locus (e.g., AA x aa).

monophyletic group: A number of relatives (individuals, species, etc.) who are all the descendants of their last common ancestor.

monoploidy (monosomy): An aberrant, aneuploid state in a normally diploid cell or organism in which one chromosome is missing, leaving one chromosome with no homolog.

monotypic: A taxon containing limited variation or internal subdivision, with one immediately subordinate taxon (e.g., a species with only one subspecies or race).

morph: Any of the genetic forms (individual variants) that account for polymorphism.

morphemes: Meaningful combinations of sound units in a language.

morphocline: A continous gradation of anatomical change over space and time.

morphology: The form, shape, and/or structures of organisms.

morphospecies: A typological species recognized on the basis of morphological differences or discontinuities.

mosaic evolution: Evolution that proceeds at different rates for different features.

Mossbauer spectroscopy: A technique used in the analysis of artifact composition, particularly iron compounds in pottery. It involves the measurement of the gamma radiation absorbed by the iron nuclei, which provides information on the particular iron compounds in the sample, and hence on the conditions of the firing when the pottery was being made.

motor area (of the brain): The posterior region of the frontal cortex that controls motor movements.

mRNA splicing: A process whereby an intervening sequence between two coding sequences in an RNA molecule is excised and the coding sequences ligated (spliced) together.

MSA: Middle Stone Age.

mudstone: General term used to describe a very fine-grained sedimentary rock. Mud-sized particles that have solidified under water or underground are often identified as mudstone.

multi-dimensional scaling (MDSCAL): A multivariate statistical technique which aims to develop spatial structure from numerical data by estimating the differences and similarities between analytical units.

multifactorial trait: A trait influenced by multiple genes and environmental factors.

multigene family: A set of related genes that have evolved fromm some ancestral gene through the process of gene duplication.

multiple alleles: Many alternative forms of a single gene.

multiple cloning site: See polylinker.

multiple crossovers: More than one crossover occurring in a particular region of a chromosome in a meiosis.

multiplier effect: A term used in systems thinking to describe the process by which changes in one field of human activity (subsytem) sometimes act to promote changes in other fields (subsystems) and in turn act on the original subsytem itself. An instance of positive feedback, it is thought by some to be one of the primary mechanisms for societal change.

Multiregional evolution: (Ethnogenesis, restricted gene flow and isolation by distance) The evolutionary model that posits humans evolved as an interconnected polytypic species from a single origin in Africa. The small population effects during initial colonization outside Africa, and adaptations to local conditions, helped establish regional differences, which were subsequently maintained through isolation-by-distance and adpative variation. Advantageous changes spread widely because of genic exchanges and the common background of the evolving cultural system whose elements could also spread.

multivariate explanations: Explanation of culture change, e.g. the origin of the state, which, in contrast to monocausal approaches, stresses the interaction of several factors operating simultaneously.

multivariate statistics: Statistical procedures that are designed to treat simultaneously (and to assess relationships among) several variables per object.

mutagen: Any physical or chemical agent that significantly increases the frequency of mutational events above a spontaneous mutation rate.

mutant allele: Any alternative to the wild-type allele of a gene. Mutant alleles may be dominant or recessive to wild-type alleles.

mutation: An error in replication or other alteration of the nucleotide base sequence creating a change in the sequence of base pairs on a DNA molecule. If the change occurs in the DNA of a somatic cell, the mutation may cause a change in the organism’s phenotype (leading, for example, to cancer) but will not affect the organism’s offspring; only mutations in the germ cells can cause heritable changes in the offspring.

mutation frequency: The number of occurrences of a particular kind of mutation in a population of cells or individuals.

mutation rate: The probability of a particular kind of mutation as a function of time.

mutator gene: A mutant gene that increases the spontaneous mutation frequencies of other genes.

Bibliography

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.