Glossary

A PRIORI
Known though reasoning and/or intuition along, independently of physical evidence.
AGNATHAN
A jawless vertebrate.
AMORPHOUS
Formless, without easily-defined shape.
ALTRUISM
Unselfishness.
ANOMALOUS
Not in accordance with normal expections.
ANTERIOR
Forward; front.
ANTERO-POSTERIOR
Front-to-back.
APPENDICULAR
Pertaining to appendages, particularly the limbs of animals.
ARCHETYPE
A fundamental original pattern.
ARTICULATION
A joint or jointed part.
ARTHROPOD
An invertebrate animal with a segmented trunk and, in many cases, segmented limbs.
ASSIMILATE
To ingest and absorb; to eat.
ATAVISM
A throwback; reoccurrence of features normally no longer evident in a lineage.
AUDITORY
Pertaining to hearing or hearing organs.
AXIAL
Forming an axis; pertain to a main axis or trunk.
BILATERAL
Two-sided; pertaining to both sides.
BIOGENETIC LAW
A theory maintaining that embryonic development parallels evolutionary development, aka recapitulation theory.
BIOTA
Living things; the totality of animal and plant life of a realm.
BISERIAL
Arranged in a linear sequence of pairs.
CAMBRIAN
Pertaining to or appearing in the period from 570 million to 500 million years ago.
CAMBRIAN BOOM
The period of explosive evolutionary development over 500 million years ago, during which the major types of animals appeared.
CARAPACE
The shell or armor covering the back of various animals.
CARTILAGE
A structural or skeletal animal tissue, softer and more flexible than bone.
CHORDATE
An animal having a notochord, or primitive spinal structure, at some stage of development; a member of the phylum Chordata, such as a vertebrate.
CHROMOSOME
Bodies within the cell which are composed of DNA.
CLADISTICS
The science of evolutionary genealogy.
COELACANTH
A type of fish, nearly extinct, noted for its lobe-fins, fins with a long limb-like base, intermediate in form between typical fins and the limbs of land animals. (pronounced see-la-canth).
COELOM
The main body cavity of metazoans, enclosing most major organs. (pronounced see-lom).
COLONIAL ORGANISM
An organism consisting of separate yet interdependent component organisms.
CONCATENATION
A linked series; a chain of elements.
CONJUNCTIVE
Connective; connecting.
CONVERGENCE
In evolutionary biology, the independent formation of similar characteristics in different lineages.
CRANIAL
Pertaining to the skull.
CREATIONISM
The belief that the origin and nature of life should be explained by reference to a supernatural agent.
CROSSOPTERYGIAN
A lobe-finned fish such as a coelacanth.
DEISM
The belief that the world was created and set in motion by a supernatural agent which subsequently does not intervene.
DEVELOPMENT
The process of growth producing the adult organism, including embryonic growth.
DIFFERENTIATION
Process of becoming different, distinct, or discrete.
DISCRETE
Distinct; separate.
DIPLODOCUS
A large dinosaur with a long neck and a long tail.
DISTAL
Distant; outward; farthest from the center.
DNA
Deoxyribonucleic acid; the material of the chromosomes. DNA molecules are long chains; genetic information is encoded in the ordering of the elements of these molecules.
DORSAL
Pertaining to the back.
ECOLOGY
The study of the economy of nature, the interactions of organisms with one another and with the inorganic environment.
ECOSYSTEM
A complex of interdependent organisms and inorganic components.
EDIACARAN
Pertaining to an ancient multicellular fauna existing prior to the Cambrian boom.
EMBRYO
An organism in early stages of development or growth.
EMPIRICAL
Pertaining to facts gained through sense perception.
ENDOMITOSIS
Multiplication of chromosomes without division of the nucleus and reproduction of the cell.
ENDOSKELETON
An internal skeleton.
EQUINE
Pertaining to horses.
ETHOLOGY
The science of animal behavioR.
EXOSKELETON
An external skeleton.
EXTRAPOLATION
Estimation of data beyond the range of what is known by assuming continuation of trends or patterns within known data.
FAUNA
Animals; animal life.
FINITUDE
Limitation; exhaustibility.
FLEXURE
Folding or bending.
GENE
A unit of inheritance; an hereditary factor.
GENETIC
Pertaining to heredity and variation.
GENETICS
The science of heredity and variation.
GENOME
The genetic information of an organism; its chromosomes.
GENOTYPE
The genetic information of an organism, in contrast to phenotype, the actual organism developing in accordance with the genotype.
GIRDLE
The anchoring and supporting bones linking vertebrate limbs to the trunk.
GNATHOSTOME
A vertebrate with jaws.
HETEROCHRONY
Change in the relative timing of aspects of development.
HETEROGENEOUS
Variegated; composed of differing parts.
HEURISTIC
Pertaining to, or helping in, discovery.
HERITABLE
Capable of being inherited.
HOMOLOGY
Similarity due to common ancestry.
HYBRID
Offspring of parents of different species or varieties.
INCIPIENCE
Beginning.
INGESTION
Eating; assimilation.
INTEGRATION
Unification.
LANCELET
A simple fishlike animal.
LARVA
An early stage of growth which differs markedly from the adult.
LIMB BUD
The early embryonic form of the vertebrate limb.
LONGITUDINAL
Lengthwise; along the main axis.
LUNGFISH
A family of fishes having both gills and lungs.
MELANOCYTE
A cell producing pigmentation.
METAZOAN
A multicellular organism.
MICROMUTATION
A slight change in the heritable nature of a species.
MINUTIAE
Particulars; details.
MITOSIS
The multiplication of chromosomes and splitting of the nucleus which culminates in cell division.
MOLECULAR BIOLOGY
The study of life at the molecular level, particularly the study of DNA.
MOLECULAR EVOLUTION
Evolutionary change at the molecular level, especially regular gradual change in DNA which may indicate the relative timing of genealogical divergences.
MOLLUSK
An invertebrate animal such as a snail or shellfish.
MORPHOLOGY
The study of the form and structure of organisms; or, the form itself.
MUTATION
A change in offspring of a species; in evolutionary biology, only heritable mutations are of interest.
NASCENT
Newly born, with a propensity for immediate interactivity, change, or growth.
NEOTENY
The attainment of adulthood (sexual maturity) while retaining some normally juveile features, through truncation of ontogeny.
NUCLEUS
A distinct body within the cells of metazoans and most plants, the fission of which initiates cell division. the nucleus contains the chromosomes.
ONTOGENY
The development or growth of an organism, particularly as an embryo.
ORGANELLE
Any specialized organ within the cell.
OSSICLE
A small bone such as exists in the inner ear of some vertebrates.
PAEDOMORPHOSIS
Adulthood and sexual maturity attained with retention of juvenile features, through alteration of normal ontogeny.
PALEOZOIC
Pertaining to or existing in the Paleozoic era, from 570 to 240 million years ago.
PARABIOSIS
Siamese-twinning; life side-by-side; the physical joining of organisms through natural mutation or experimental procedures.
PARADIGM
A general idea, model, or pattern.
PARALLELISM
In evolutionary biology, similar paths of evolutionary development in lineages of common ancestry.
PECTORAL
Pertaining to the chest or the anterior paired limbs of vertebrates.
PELVIC
Pertaining to the skeletal structure supporting the posterior paired limbs of vertebrates.
PHENOTYPE
The actual apparent organism, in contrast to the genotype, the genetic information upon which the phenotype is based.
PHYLOGENY
Evolutionary history; genealogy of species.
PHYLUM
A fundamental division or category of animals or plants.
PINCERS
A grasping organ.
POLYDACTYLY
Condition of having more fingers or toes than normal.
POPULATION GENETICS
The study of the movements and effects of genes within populations and gene pools.
POSTERIOR
Located toward the rear.
PREADAPTATION
The suitability of an existing feature for a new use.
PRIMITIVE
In evolutionary biology, this term often means ancestral or genealogicaly prior, yet sometimes it means simple or crude. Under a simple-to-complex evolutionary paradigm, the two senses are often confused.
PROCRUSTEAN
Suggestive of Procrustes, a Greek mythological figure who enforced conformity.
PROGENITOR
Direct ancestor.
PROTO
Prefix: first; preliminary; original.
PRIMATE
A member of the order of mammals which includes lemurs, monkeys, and man.
PROXIMAL
Near; inward; closest to the center.
PTERODACTYL
An extinct winged reptile.
RADIAL
A ray, bone, or chain of bones projecting from a central point or axis.
RANDOM
Haphazard; not determined by any known pattern.
RAY
A supportive spine of a fin, typically numerous and composed of cartilage.
RECAPITULATION
The appearance of structures during development which are no longer present in the adult; or, the theory that embryonic growth directly illustrates evolutionary history.
RHIPIDISTIAN
An ancient reptile.
SCENARIO
Outline, plan, or synopsis.
SECRETE
To produce and give off a substance.
SEGMENTATION
The condition of being divided into distinct segments.
SERIAL HOMOLOGY
Condition in which homologous structures (structures which are similar due to common ancestry) are arranged in linear order, forming a chain of segments.
SOMITE
A body segment; especially, in vertebrates, a segment in the early embryo.
STASIS
Stability; changelessness.
SYMBIOTIC
Pertaining to dependence or interdependence between different organisms.
SYMMETRY
Equality in size and form between parts; correspondence or repetition of a pattern between or within structures within an organism.
TAXONOMY
The science of classification of organisms.
TETRAPOD
A terrestrial vertebrate with four limbs.
TRILOBITE
An extinct crustacean of the subphylum trilobitomorpha.
TRUNCATE
To shorten; to cut off.
TUNICATE
An invertebrate animal of the subphylum Urochordata.
VERTEBRA
(plural VERTEBRAE). A segment or bone of the spinal column.
VERTEBRATE
An animal with a segmented spinal column; a member of the subphylum Vertebrata.
VESTIGE
A degenerate structure; a remnant or trace.

Table of Contents