ontogeny
Organism's life development
Ontogeny is the developmental history of an individual organism from embryo to adult.
The term appears in biology and psychology when tracing how a single creature grows and changes over its lifespan, as distinct from phylogeny, which tracks the evolutionary history of a species: The ontogeny of the nervous system begins in the first weeks after conception.
The phrase ontogeny recapitulates phylogeny—the now-discredited idea that embryonic development replays evolutionary stages—was once influential in biology.
Evolutionary relationships among organisms
- evolutionSpecies changing over generations
- recapitulationSummarizing what came before
- HaeckelGerman zoologist, Darwin champion
- ancestryFamily line of descent
Immature feeding stage
- pupaInsect's resting stage
- chrysalisPupal casing for metamorphosis
- cocoonSilk wrapping for transformation
- tadpoleImmature aquatic amphibian
caterpillar · nymph · instar · imago · molting · pupation · neoteny · transformation
Formation of early life
- gastrulationEmbryo forms primary layers
- zygoteFirst embryonic cell
- fertilizationGamete fusion creating zygote
- cleavageTendency to split cleanly
organogenesis · germinal · morphogenesis · induction · patterning · determination · competence · regulative
Increase in length
- hypertrophyTissue enlargement via cells
- hyperplasiaExcessive cell multiplication
- anabolismMetabolic construction of molecules
- accretionGrowth through external addition
Organism's full developmental sequence
- germinationSeed's initial growth phase
- sproutingSeeds beginning growth
- maturationProcess of becoming complete
- pubertySexual development stage
adolescence · adulthood · senescence · aging · juvenility · fledging · weaning · sexual maturity
Recognizing meaningful differences
- proliferationRapid increase in quantity
- cell divisionParent splitting into offspring
- mitosisNuclear division producing identical cells
- cellularComposed of small units
phenotypic · genotype · epigenetics · plasticity · apoptosis · signaling · gene expression · stem cell
phylogeny
Evolutionary relationships among organisms
- evolutionSpecies changing over generations
- recapitulationSummarizing what came before
- HaeckelGerman zoologist, Darwin champion
ancestry · cladistics · conserved · homology · common ancestor
larva
Immature feeding stage
- pupaInsect's resting stage
- chrysalisPupal casing for metamorphosis
- cocoonSilk wrapping for transformation
tadpole · caterpillar · nymph · instar · imago · molting · pupation · neoteny · transformation
embryogenesis
Formation of early life
- gastrulationEmbryo forms primary layers
- zygoteFirst embryonic cell
- fertilizationGamete fusion creating zygote
cleavage · organogenesis · germinal · morphogenesis · induction · patterning · determination · competence · regulative · canalization
elongation
Increase in length
- hypertrophyTissue enlargement via cells
- hyperplasiaExcessive cell multiplication
- anabolismMetabolic construction of molecules
life cycle
Organism's full developmental sequence
- germinationSeed's initial growth phase
- sproutingSeeds beginning growth
- maturationProcess of becoming complete
puberty · adolescence · adulthood · senescence · aging · juvenility · fledging · weaning · sexual maturity · flowering
differentiation
Recognizing meaningful differences
- proliferationRapid increase in quantity
- cell divisionParent splitting into offspring
- mitosisNuclear division producing identical cells
cellular · phenotypic · genotype · epigenetics · plasticity · apoptosis · signaling · gene expression · stem cell · progenitor
ontogenyphylogeny
Evolutionary relationships among organisms
phylogenesis · macroevolution · speciation · evolutionary history · evolution
ontogenysenescence
Gradual functional decline with age
degeneration · atrophy · decay · involution · regression