Particulate inheritance

The theory of particulate inheritance is an idea that originated with Mendelian theorists (or by Mendel himself) stating that characteristics can be passed from generation to generation through "discrete particles" (which meant genes). These particles can keep their ability to be expressed while not always appearing in descending generation.^[1]

File:Mendel.png

Gregor Mendel, the Father of Genetics

Scientific developments leading up to the theory

Early in the 19th century, scientists had already recognized that Earth has been inhabited by living creatures for a very long time. On the other hand, they did not understand what mechanisms actually drove biological diversity. They also did not understand how physical traits are inherited from one generation to the next. Blending inheritance was the common ideal at the time, but was later discredited by the experiments of Gregor Mendel. Mendel proposed the theory of particulate inheritance by using pea plants (Pisum sativum) to explain how variation can be inherited and maintained over time.

Blending Model vs. Particulate Model

• Blending Model:
  • Offspring are a blend of both parents
  • The characteristics of the blended offspring are passed on to the next generation
  • Variation is washed out over time^[2]

• Particulate Model:

Mendel's Methods

Mendel's Laws

Since Mendel used experimental methods to devise his particulate inheritance theory, he developed three basic laws: the Law of Segregation, the Law of Independent Assortment, and the Law of Dominance.^[3]

See also

• Blending inheritance
• Mendelian inheritance
• Modern synthesis

Notes

1. "Particulate theory of inheritance", WebRef
2. Particulate Model of Inheritance, BioEd Online
3. Ibid.

References

• Campbell, N. E. & Reece, J. B. (2002). Biology (6th ed.). San Francisco: Benjamin Cummings.

• "Particulate inheritance." BioEd Online. Retrieved 3-5-2009 from BioEd Online Slides