Evolution - Evidence for Biological Evolution

Paleontological Evidence: Fossils found in sedimentary rocks indicate the life forms that existed during specific geological time scales. The age of fossils is often determined using radioactive dating such as $^{14}C$ dating.

Morphological and Comparative Anatomical Evidence: Based on similarities and differences between organisms. It includes Homologous and Analogous organs.

Homologous Organs: Structures with the same fundamental architecture and embryonic origin but performing different functions (e.g., thorns of $Bougainvillea$ and tendrils of $Cucurbita$). This represents Divergent Evolution.

Analogous Organs: Structures that are anatomically different but perform similar functions (e.g., wings of a butterfly and wings of a bird). This represents Convergent Evolution.

Biochemical Evidence: Similarities in proteins and genes (e.g., $DNA$, $RNA$, and $Cytochrome$ $c$) performing the same function across different species suggest a common ancestry.

Adaptive Radiation: The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (e.g., Darwin's Finches and Australian Marsupials).

Embryological Evidence: Proposed by Ernst Haeckel but later disproved by Karl Ernst von Baer. Von Baer noted that embryos never pass through the adult stages of other animals.

Evidence by Natural Selection: Observed in Industrial Melanism in the moth $Biston$ $betularia$. Before industrialization, white-winged moths survived better; after industrialization, dark-winged (melanised) moths had a survival advantage due to soot-covered trees.