About $200$ million years ago,some land reptiles went back into water to evolve into fish-like reptiles. These reptiles were known as:

Mark the correct statements:
$I.$ Fitness of individuals means reproductive fitness.
$II.$ Homology in vertebrate brain indicates common ancestry.
$III.$ Theory of acquired characters was given by de Vries.
$IV.$ After industrialization,the white moth did not survive due to predators.
The correct option is:

Identify the correct statement from the given options.

In recent years,$DNA$ sequences (nucleotide sequence) of $mt-DNA$ and $Y$-chromosomes were considered for the study of human evolution,because

........ is the largest land reptile.

Galapagos islands are located in