Phylogeny and Evolutionary Relationships

Describing the process of evolution in terms of past and present geographic distribution of species is termed as biogeography. Evolutionary theories based on comparative study of the structural details of features found in different but related organisms reveals the process of evolution in terms of basic similarities and differences among them. These are termed as comparative anatomy. Comparative embryology defines the process of evolution in terms of basic similarities and differences in embryological development.  Natural selection is the evolutionary force that favors the mutation conferring “fitness” to organisms thereby leading to the evolution of fittest species. Evolutionary theories based on similarities and differences in DNA sequences of different but related species defines their evolution in terms of molecular biology. Thus, the correct answer is option E.

Cytochrome C is a highly conserved protein found in the mitochondria of many organisms. Comparing the amino acid sequence of cytochrome C is a standard method for determining evolutionary relationships and common ancestry.

Cladistic analysis focuses on shared derived characters (synapomorphies) to build phylogenetic trees. It explicitly distinguishes between homologous and analogous characters, making option D the incorrect statement.

If two species have evolved from a recent ancestor, there will be a greater DNA match between the two newly formed species and also the ancestor.

Organisms that share more amino acid sequence homology for commonly occurring proteins are supposed to be diverged from each other recently and share more recent ancestors. Since cytochrome c protein of human and rhesus monkey exhibit single difference while those of human and kangaroos exhibit ten differences, human and rhesus monkey are supposed to share more recent ancestors than human and kangaroos. Thus, the correct answer is D.

Different organism show similarities in physiology and biochemistry thus proved that all animals have evolved from same common ancestor determining phylogenetic relationships.

The doubling of its chromosome number was presumably by errors in mitosis or meiosis within the animal's reproductive organs.A comparison of the chromosomes of the red viscacha rat and the mountain viscacha rat suggested that the chromosomes of the red viscacha rat increased relatively rapidly (in evolutionary terms) due to a diverse set of highly repetitive elements. So, the correct answer is " Errors in meiosis".

Homo erectus had an average cranial capacity of approximately 900-1100 cm³, while Homo sapiens averages approximately 1350 cm³. This size difference is a key morphological distinction between the species. The other options are incorrect: both species originated in Africa (Homo erectus did migrate to Asia), size comparisons are complex, and Homo erectus did leave Africa. The correct answer identifies the brain size difference, despite the typographical error 'eructus' for 'erectus'.

Scientists working across a variety of disciplines have discovered evidence of common descent among the living organisms on earth.  This evidence which constructs a theoretical framework on which evolutionary theory rests demonstrates the natural processes  of earth's biodiversity. These studies are based on fossil studies and comparison of the DNA genetic sequences thereby revealing phylogenetically closer organisms. A protein is a chain of amino acids and the functional end-product of a gene. Studies by evolutionary scientists involve the comparative analysis of both DNA and protein sequences and comparing the same type of gene or protein sequence between organisms helps to determine the closeness of a relation.  According to their studies, two organisms are considered closely related if they share a high percentage of amino acid sequence similarity for a certain protein. The recent studies however, bring to light the close resemblance of Birds to the extinct dinosaur. Thus, the correct answer is option A.

Even though birds lost teeth as physical structures between 60 and 80 million years ago, several studies have shown that those tissues within birds that would normally produce teeth still retain the potential to do so. For example, in 1821, Geoffrey St. Hilaire was the first scientist to publish the observation that some bird embryos exhibited evidence of tooth formation, but his contemporaries considered his work flawed.