Ontogeny repeats phylogeny.. Biogenetic law.. May pls anyone elucidate it..

Question

Ontogeny repeats phylogeny..  Biogenetic law..  May pls anyone elucidate it..

Answer

development of an organism (ontogeny) expresses all the intermediate forms of its ancestors throughout evolution (phylogeny).

Answer

The theory of recapitulation, also called the biogenetic law or embryological parallelism—often expressed using Ernst Haeckel's phrase 'ontogeny recapitulates phylogeny'—is a hypothesis that the development of the embryo of an animal, from fertilization to gestation or hatching (ontogeny), goes through stages

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Tubler secretions take place

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Ontogeny Repeats Phylogeny: Biogenetic Law Explained

The concept of 'ontogeny repeats phylogeny' is a key principle in the field of developmental biology. It suggests that the development of an individual organism, from fertilization to adulthood, recapitulates the evolutionary history of its species. This idea, also known as the biogenetic law, was originally proposed by German biologist Ernst Haeckel in the late 19th century. Let's delve into the details of this concept.

Ontogeny and Phylogeny: Definitions
1. Ontogeny: Ontogeny refers to the individual development of an organism from conception to maturity. It encompasses the series of morphological, physiological, and behavioral changes that occur throughout an organism's life cycle.
2. Phylogeny: Phylogeny, on the other hand, refers to the evolutionary history and relationships among different species. It represents the branching patterns of the 'tree of life' and the common ancestry of organisms.

The Biogenetic Law
The biogenetic law proposed by Haeckel suggests that during ontogeny, an individual organism goes through stages that resemble the ancestral forms of its evolutionary lineage. In other words, the developmental stages of an organism mirror the evolutionary history of its species.

Evidence and Examples
1. Gill Slits in Human Embryos: One of the most well-known examples supporting the biogenetic law is the presence of gill slits in human embryos during early development. These structures resemble the gill slits found in fish and other aquatic organisms, indicating a shared evolutionary ancestry.
2. Tail Development: Another example is the presence of a tail during early embryonic stages in humans. This tail eventually regresses as development progresses, reflecting the evolutionary history of tailed ancestors in our lineage.
3. Limb Development: The development of limbs in different organisms also follows a similar pattern. For instance, the limb buds of vertebrates, including humans, start as simple outgrowths and then differentiate into more complex structures like fingers or toes.

Interpretation and Limitations
While the biogenetic law has provided valuable insights into the relationship between ontogeny and phylogeny, it is important to note its limitations:
1. Oversimplification: The law does not imply a strict one-to-one correspondence between each stage of ontogeny and phylogeny. It is more of a general pattern rather than an exact replication of evolutionary history.
2. Embryonic Variation: Different species may exhibit variations in the developmental stages or structures observed during ontogeny, making it challenging to find universal patterns across all organisms.
3. Evolutionary Loss: Some ancestral features may be lost or modified during evolution, resulting in incomplete or altered recapitulation during ontogeny.

Conclusion
While the biogenetic law has faced criticism and refinement over the years, it remains an influential concept in developmental biology. The idea that ontogeny repeats phylogeny provides a framework for understanding the relationship between individual development and evolutionary history. By studying the developmental stages of organisms, scientists can gain insights into their evolutionary past and shed light

Similar NEET Doubts

Haeckel's biogenetic law is (1) ontogeny repeats phylogeny (2) phylogeny repeats ontogeny (3) reproductive isolation (4) every organism is produced by its parents?

According to Haeckels biogenetic [CPMT CPMT 77, 79]

Which one of the following statement is correct?[2007]

According to recapitulation theory[NCERT 75, CPMT 82]

Man is called an walking museum because

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