BIO NMDCAT

The kiwi bird lives on the ground with few predators; its lack of flight led to the disuse of wings, causing them to shrink and become vestigial over generations.

Lamarck's "Philosophie Zoologique" was published in 1809, which is in the early 19th century.

Lamarckism posits that the plant responds to the environmental dry stress by adapting its physiology (succulence) to meet its new need, then transmitting this acquired trait.

Darwin proposed Pangenesis to explain how physical modifications in body parts might be communicated to reproductive cells, aligning closely with Lamarckian inheritance.

Lamarck's first postulate suggested that living organisms possess an inherent internal vital force that drives them toward greater organizational complexity.

Under the use and disuse principle, frequent running strengthens and elongates the limbs, and under the inheritance of acquired characters, this trait is passed down.

Both Darwin and Lamarck recognized that organisms adapt to their environments over time, though they proposed different mechanisms for how these adaptations occur.

Lamarck proposed that the giraffe's ancestors had short necks but stretched them to reach leaves on high branches, leading to a longer neck through "use" which was then inherited.

Lamarckism is rejected because somatic changes (acquired characters) cannot alter germ-line DNA, meaning they cannot be inherited under modern genetic principles.

Genetic engineering alters the genome directly. Lamarckism refers to somatic phenotypic changes (like organ use/disuse) being converted into heritable genetic info, which does not happen here.

Under Lamarckism, the disuse of wings because of terrestrial lifestyle and abundant ground-level resources led to the degeneration of wings over generations.

Lamarck argued that variations are purposefully acquired during life in response to environment, whereas Darwin proposed that variations exist naturally in a population before natural selection acts.

Under Lamarckism, the mental training/acquired skill of navigating the maze would be passed to the offspring, making subsequent generations progressively better at it without training.

Lamarckism explains vestigial organs (like the human appendix, coccyx, or wisdom teeth) as structures that lost their function and gradually degenerated due to continuous disuse over generations.

This is Lamarck's second postulate (environmental changes produce new needs, which lead to the development of new organs through effort or behavior).

Mutilating the tail alters somatic tissue (somatoplasm) but leaves the germplasm (reproductive cells) untouched, demonstrating that somatic changes are not inherited.

Orthogenesis (straight-line evolution) is conceptually linked to Lamarck's internal vital force, suggesting organisms have an innate drive to evolve in a specific, progressive direction.

Lamarck explained webbed feet as an acquired physical modification resulting from the continuous effort of spreading the toes to push water while swimming.

While Lamarck recognized adaptation to the environment, he did not propose natural selection (survival of the fittest based on pre-existing genetic variations) as the mechanism.