Ontogeny is the origination and development of an organism, usually from
the time of fertilization of the egg to the organism's mature form. Yet, the
term can be used to refer to the study of the entirety of an organism's
lifespan. Ontogeny pertains to the developmental
history of an organism within its own lifetime, as distinct from phylogeny,
which refers to the evolutionary history of a species. In practice, writers on
evolution often speak of species as "developing" traits or characteristics.
This can be misleading. While developmental processes can influence
subsequent evolutionary processes, individual organisms develop, while
species evolve. Ontogeny, embryology and developmental
biology are closely related studies and the terms are sometimes used
interchangeably. Recently, the term ontogeny has been used in cell biology
to describe the development of various cell types within an organism.
Ontogeny is a useful field of study in many disciplines, including
developmental biology, developmental psychology, developmental cognitive
neuroscience, and developmental psychobiology.
Ontogeny is also a concept used in anthropology as "the process through
which each of us embodies the history of our own making".
Etymology The word ontogeny comes from the Greek
ὄν, on, i.e. "being; that which is", which is the present participle of the
verb εἰμί, eimi, i.e. "to be, I am", and from the suffix -geny from the Greek
-γένεια -geneia, which expresses the concept of "mode of production".
Nature and nurture A seminal paper named ontogeny as one of
the four primary questions of biology, along with Huxley's three others:
causation, survival value and evolution. Tinbergen emphasized that the change of
behavioral machinery during development was distinct from the change in behavior
during development. "We can conclude that the thrush itself, i.e. its
behavioral machinery, has changed only if the behavior change occurred while
the environment was held constant...When we turn from description to causal
analysis, and ask in what way the observed change in behavior machinery
has been brought about, the natural first step is to try and distinguish
between environmental influences and those within the animal...In ontogeny
the conclusion that a certain change is internally controlled is reached by
elimination. " Tinbergen was concerned that the elimination of environmental
factors is difficult to establish, and the use of the word "innate" is often
misleading. Ontogenetic allometry
Most organisms undergo dramatic changes in shape as they grow and mature. Even
"reptiles", in which the offspring are often viewed as miniature adults, show a
variety of ontogenetic changes in morphology and physiology.
Anthropological application Comparing ourselves to others is
something humans do all the time. "In doing so we are acknowledging not so
much our sameness to others or our difference, but rather the commonality
that resides in our difference. In other words, because each one of us is at once
remarkably similar to, and remarkably different from, all other humans, it
makes little sense to think of comparison in terms of a list of
absolute similarities and a list of absolute differences. Rather, in respect
of all other humans, we find similarities in the ways we are
different from one another and differences in the ways we are the same.
That we are able to do this is a function of the genuinely historical
process that is human ontogeny". See also
Recapitulation theory, the idea that ontogeny recapitulates phylogeny
Organogenesis Ontogeny
Phylogenetics Phylogeny
Apoptosis - Cell death in specific locations due to inherited genetic
instructions. Notes and references
External links Media related to Morphogenesis at
Wikimedia Commons The dictionary definition of ontogeny at
Wiktionary