Mutation: Mutation is a random change in the base
sequence of DNA.
Adaptation: Adaptation is any characteristic which is
advantageous to an organism or a population and which helps to adjust itself
to the environment in which it lives.
Speciation: Speciation is the formation of new species
from pre-existing simple species.
Gene Pool: Gene pool is the total number of genes
present in a population.
Homologous Organs: Homologous are those organs which
have similar origin as well as basic structure but are differently adapted to
perform different functions. For example, legs in different insects, human
Analogous Organs: Analogous organs are those organs which
perform similar function but different basic structure and origin. For
example, wings of a bird and insect.
Connecting Links: Connecting links are those living organisms
which possess characters of two different group of
Vestigial Organs: Vestigial organs are the organs which are
non-functional in an organism but which are functional in related animals.
Atavism: Atavism is the reappearance or refunctioning of some vestigial organs. For example,
appearance of tail in human being.
Fossils: Fossils are the remains of hard parts of
ancient animals which are found preserved in some rocks or in any other
Geological Time Scale: From the origin of earth till date,
time has been divided into a scale. This scale is called geological time
Missing Links: Missing links are those extinct organisms
which had the characters of two different group of
Palaeontology: Is the study of
Crossing over: The exchange of segments between the
non-sister chromatids of homologus