Lamarck’s theory of evolution proposed by a French naturalist and biologist named Jean-Baptise Lamarck.
In his book Philosophie zoologique, Lamarck argues that evolution occurs due to internal drives within living things and these changes are passed down to the next generation.
The change in living things is to increase the size and function that is superior in life. Lamarck’s theory of evolution is not generally accepted because it has weaknesses. Here are the drawbacks Lamarck’s theory of evolution!
Also read: Evolution: Definition and Development
Have no proof
Basically Lamarck’s theory of evolution is a concept that has no evidence. Lamarck did not have scientific evidence to support his theory, so this theory was widely criticized.
Evolution is not always an increase in size
Reported from Online Biology Notes, Lamarck related evolution as the tendency of certain groups of organisms to change and increase in size. However, the available evidence suggests that evolution did not go that way.
Evolution doesn’t always increase in size
Evolution does not always increase the size of living things, but also reduces their size. For example, many ancient plants and animals were large but evolved to be smaller.
For example, ancient ferns were once giant in size, now shrinking smaller after evolving.
Also read: Evolution and Its Various Theories
Contradictions with August Weisman
Lamarck viewed evolution in a simple way, where changes occur as a result of the body parts used. For example, a giraffe tries to get food on tall trees, so its neck slowly lengthens.
Lamarck assumes the change was directly passed on to the next offspring of the giraffe. This was opposed by a German biologist named August Friedrich Leopold Weismann.
Reported from Encyclopedia Britannica, Weissman showed that germplasm continuity is sufficient to explain the heritable characteristics of all individual traits of a species without needing to postulate contributions from body cells.
According to Weissman, there is nothing to do with the use of an organ into the evolution as stated by Lamarck.
Reported from The Embryo Project Encyclopedia, Weissman also assumes that changes that occur in somatic cells (body cells) cannot be passed on to germ cells (egg cells and sperm cells). Thus, Weissman rejects the characteristics of inheritance proposed by Lamarck.
Contrary to Darwin’s theory
After Lamarck’s theory was made public, fifty years later Darwin put forward his theory of evolution. Despite some similarities, there are contradictions between Lamarck’s and Darwin’s theories of evolution.
Lamarck thought that evolution occurred due to internal factors in living things. Meanwhile, Darwin assumed that evolution occurred due to external factors in the form of natural selection.
Get updates news of choice and breaking news every day from Kompas.com. Let’s join the Telegram group “Kompas.com News Update”, how to click the link https://t.me/kompascomupdate, then join. You must first install the Telegram application on your cellphone.