|
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.
|
