Ontogeny vs Phylogeny: Difference and Comparison

Ontogeny is focused on the study of individuals. It tries to debunk the processual steps of growth included in developing a ‘complete’ organism. Conversely, Phylogeny is focused on studying particular populations as against the individual organism.

It enhances our understanding of how species develop and evolve.

Key Takeaways

1. Ontogeny refers to the development of an individual organism from fertilization to maturity, while phylogeny refers to the evolutionary history and relationships between different groups of organisms.
2. Ontogeny is concerned with the growth and development of an individual, while phylogeny is concerned with the larger picture of how different organisms are related.
3. Ontogeny is often studied in developmental biology, while phylogeny is studied in evolutionary biology.

Ontogeny vs Phylogeny

The difference between Ontogeny and Phylogeny is that the former is a specific branch of science that studies the growth and development of an individual organism. At the same time, the latter is also a branch of science, but it investigates any species’ evolutionary development process.

Comparison Table

Parameters of Comparison	Ontogeny	Phylogeny
Definition	Ontogeny is the branch of science investigating the historiography of an individual organism’s development.	Phylogeny is the branch of science investigating a particular species’ evolutionary history.
Translations	Ontogeny is a Greek word that can be translated to connote the ‘origin of being’.	Phylogeny is a Greek word that can be translated to connote the ‘origin of tribes or kind’.
Emphasis Of Analysis	Individuals are the focal point of all research conducted within the field of Ontogeny.	Populations are the focal point of all research conducted within Phylogeny.
Central Theory	The central theory of Ontogeny is based on the evaluation of the development process of an organism from a single cell to a ‘complete’ organism.	The central theory of Phylogeny is based on evaluating the complete trajectory of development that characterizes an entire species.
Application of the Theory	Ontogenesis is important in developmental biology, developmental cognitive neuroscience, etc.	Phylogeny is important in the fields of forensics, bioinformatics, etc.

What is Ontogeny?

Ontogeny is a scientific school of thought that studies and examines an individual organism’s development process. It considers the origin of the individual and the steps of development that the organism has lived through.

‘Ontogeny’ derives from a Greek word that means the ‘origin of being’. Ontogenesis is focused on analyzing an organism’s physiological and psychological development.

Ontogeny is committed to examining the processual growth of the organism, right from the fertilization of the egg to the presentation of the ‘whole’ organism.

Ontogeny believes that certain ancestral qualities are still preserved in an organism. At this juncture, Ontogeny is connected with Phylogeny, as an individual’s development and features cannot occur in a vacuum.

They are inevitably a mirror image of the changes happening in the species. This creates the much-debated biogenetic model.

Ontogeny undeniably influences the growth of developmental psychology, developmental cognitive neuroscience, developmental biology, and other disciplines.

What is Phylogeny?

Phylogeny is the study of the process of evolution that each species has experienced. It is focused on understanding the history of the evolutionary process. Derived from Greek, the word means the ‘origin of tribe or kind’.

The basis of this theory is that all organisms are genetically connected. These biological and genetic connections between various species can be effectively represented using a phylogenetic tree that traces the common ancestor among species.

Phylogeny is important to understand how organisms have retained certain ancestral features while amalgamating new features that help species adapt to their ever-changing environments.

Phylogeny is important in categorizing species as well as in the development of the fields of forensics and bioinformatics.

Phylogeny is closely associated with Ontogeny. Scientist Ernest Haekel stated that ‘Ontogeny recapitulates Phylogeny’- a statement that formed the basis of all biogenetic laws. However, this has been widely contested as it does not apply to all organisms.

Main Differences Between Ontogeny and Phylogeny

1. The main difference between Ontogeny and Phylogeny is that the former is the branch of science investigating an individual organism’s development historiography. At the same time, the latter term connotes the branch of science that studies the history of evolutionary development experienced by different species.
2. The meaning of each term is also quite different. ‘Ontogeny’ can be translated to connote the ‘origin of being’. While the term ‘Phylogeny’, when translated, means ‘origin of tribe or kind’.
3. The two fields can be significantly differentiated based on the focus points of each discipline. While Ontogeny focuses on a singular individual, Phylogeny is more focused on the history of the development of a given population or species.
4. Ontogeny is centred around understanding a single organism’s growth and development process, from fertilisation to forming the ‘complete’ organism. At the same time, Phylogeny is rooted in investigating the whole evolutionary process.
5. Ontogeny is important in augmenting our knowledge of developmental psychology, developmental cognitive neuroscience, developmental biology, etc. On the other hand, Phylogeny is important in studying forensics, bioinformatics, species classification, etc.

References

1. https://www.cambridge.org/core/journals/paleobiology/article/conceptual-relationship-between-ontogeny-and-phylogeny/6A5D7B8BBA14E0E1356B49116600D757
2. https://www.karger.com/Article/Abstract/115302