Question

What is Phylogeny?

Answer 1

Hint: Phylogeny is the study of evolutionary history of a particular species. Phylogeny helps understand the background of a particular organism of a species in relation to the descent of the same species. In humans, Phylogeny is used when a particular hereditary disease is studied with reference to other members of the same family.

Complete explanation:
Phylogeny is the fundamental phenomenon in taxonomy. There is numerous evidence that can be used to study Phylogeny.
Evidence from the field of Paleontology: Paleontology is the study of the history of life on earth with the help of fossils. Fossils can be remains, imprints, molds or an entire living organism preserved in natural optimum conditions.
Evidence from the field of comparative anatomy: Homologous organs are organs evolved from identical ancestral forms that have similar structure but perform different functions, e.g., forelimbs of horse, frog and man.
Analogous organs are organs that are not evolved from identical ancestral forms and have different structures but perform the same function, e.g., wings of insects, bats and birds.
Evidence from the field of comparative embryology: Comparative embryology compares how embryos of different species are connected.
Evidence from the field of molecular genetics: Molecular genetics helps to study how differences in the DNA structure exhibits a variation in different organisms.

Note:
With the aid of Phylogeny one can study human origin, biogeography, and the origin of a particular trait. Phylogeny is essential because it helps in understanding how a species evolves. Phylogenetic trees are used as a diagrammatic representation of studying evolutionary relationships of a species.