Question

What kind of evidence suggested that man is more closely related with chimpanzees than with other hominoid apes?
A. Evidence of DNA from sex chromosomes only
B. Comparison of chromosome morphology only.
C. Evidence of fossil remains and the fossil of mitochondrial DNA alone.
D. Evidence from DNA extracted from sex chromosomes, autosomes and mitochondria.

Answer 1

The great apes belong to the Hominidae family. There are eight species belonging to the family – the orangutans, gorillas, bonobos, chimpanzees and humans. Fossil evidence can determine the closeness of one group to another and help us determine the phylogenetic relationships.

Complete answer:
Human beings are known to evolve from primate ancestors. At present, eight species remain of the great apes - the orangutans, gorillas, bonobos, chimpanzees and humans.
Out of these species, humans are said to be closest to the chimpanzees. The last common ancestor between these two species is called The Chimpanzee-Human Last Common Ancestor or CHLCA. It is said that these two species diverged around 13 million years ago in the Miocene era and completed in the Pliocene, around 4 million years ago.
Genetic evidence suggests that the chimpanzees and humans share around 98 percent of their genome. This suggestion arises from the similarities in genetic makeup of humans and chimpanzees. Studies have been conducted with mitochondrial DNA and nuclear DNA. The mitochondrial DNA is a single locus source of DNA that does not recombine and is inherited from one parent. Nuclear DNA comprises autosomes and sex-chromosomes.
DNA collected from the autosomes, sex-chromosomes and mitochondria of humans and chimpanzees have been scanned for Single Nucleotide Polymorphisms or SNP(s). SNP(s) are mutations at a single locus present throughout the genome. Similar patterns of SNP(s) indicate closeness of two species with respect to their evolution.
Apart from gene sequencing for SNP(s), the application of molecular clocks also suggests similarities between human and chimpanzee genomes. Molecular clock is a technique used to calculate the mutation rate of biomolecules like DNA, RNA or proteins in two or more species to determine the time at which the species diverged.
Fossil remains indicate morphological similarities only. DNA evidence helps us to construct phylogenetic trees.
Hence to conclude, human and chimpanzees are more closely related to each other than the other members of the family of Great Apes. This is suggested by DNA evidence from autosomes. Sex chromosomes and mitochondrial DNA.

Hence, the correct answer is option (D).

Note: Humans and chimpanzees belong to the Hominid family along with the other primates like orangutans, gorillas and bonobos. The chimpanzees are more closely related to humans than with other hominids. This has been suggested by DNA evidence collected from both the species.