Definition
noun
An evolutionary theory holding that acquired or learned traits can be passed on from parents to offspring.
Supplement
According to this theory, individuals lose characteristics they do not require (or use) and develop characteristics that are useful. These characteristics or traits are caused by changes or mutations in the organism that are directed towards some objective so the organism would become better adapted to a particular situation or to its environment, and the traits acquired or learned during its lifetime can be passed on to its offspring which would also be possessing these traits.
However, this theory is no longer widely accepted like before. For instance, according to this theory, the giraffes evolve into having long necks because of their stretching to reach for the leaves on tall trees, and this trait had been passed on to its offspring. But other leaf-eating animals with short necks would not need a long neck to survive. A sheep does not need longer neck as it can eat leaves from grass. This indicates the giraffe’s neck is long not because of the result of direct mutation nor because it is a requisite for survival, but because it is caused by random mutation.
Word origin: after the French biologist Jean-Baptiste Lamarck, who incorporated the action of soft inheritance into his evolutionary theories.
Synonym: Lamarckism.
See also: direct mutation, soft inheritance.
Dictionary > Lamarckian theory
You will also like...
Homeostatic Mechanisms and Cellular Communication
Homeostasis is the relatively stable conditions of the internal environment that result from compensatory regulatory res..
Chemical Composition of the Body
The body is comprised of different elements with hydrogen, oxygen, carbon, and nitrogen as the major four. This tutorial..
The Dinosaurs
Dinosaurs represented a major turn in the evolutionary development of organisms on Earth. The first dinosaurs were presu..
Biosecurity and Biocontrol
This lesson explores the impact of biosecurity threats, and why they need to be identified and managed. Examples to incl..
Adaptation Tutorial
Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..
Movement of Molecules Across Cell Membranes
Molecules move within the cell or from one cell to another through different strategies. Transport may be in the form of..