Question

2Discuss the value of each of the following characters for use in phylogenetic inference:

identity of nucleic acids at third positions in a codon triplet,

nucleic acid sequences in eukaryotic introns,

surface proteins in viruses,

numbers of flower parts in angiosperms,

presence of alkaloids in leaf tissues of angiosperms,

diversity of hemoglobin types within an individual organism in tetrapods,

presence or absence of specific recombination factors in bacteria,

relative limb length (limb length relative to body size) in tetrapods

Answer 1

The phylogenetic inference involves an attempt to measure the evolutionary history of a group of organisms (taxa) or a family of genes. The character given below are not play a very important role in estimate the evolutionay history of a group of organisms or a family of genes.

• identity of nucleic acids at third positions in a codon triplet,
• nucleic acid sequences in eukaryotic introns,
• surface proteins in viruses,
• numbers of flower parts in angiosperms,
• presence of alkaloids in leaf tissues of angiosperms,
• diversity of hemoglobin types within an individual organism in tetrapods,
• presence or absence of specific recombination factors in bacteria,
• relative limb length (limb length relative to body size) in tetrapods

Hence these examples mentioned above are not good for the purpose of phylogenetic inference since they are all being selected upon, we can use non-selected upon factors such as noncoding DNA for phylogenetic inference.