Question

There is variation in nucleotide sequences, but the amino acid sequences for the partial sequence presented in this case are identical between the five species. Explain why natural selection might have favored conservation of the amino acid sequence.

Answer 1

Natural selection favors conservation of amino acid sequences to maintain the functional integrity of proteins, with mechanisms like alternative splicing and the degeneracy of the genetic code mitigating mutations while preserving essential protein structure and function, all indicating a common origin of life.

Step-by-step explanation:

Natural selection might have favored the conservation of amino acid sequences across different species due to the importance of these sequences in maintaining the functional integrity of proteins. Despite variation in nucleotide sequences, these conserved amino acid sequences suggest a common ancestry and highlight the shared evolution of protein function among eukaryotes, facilitated by mechanisms such as alternative splicing and recombination.

These processes allow for the diversification of proteins without the need for additional genes, emphasizing the evolutionary conservation of essential protein structures and functions.

Intriguingly, the degeneracy of the genetic code, where multiple codons can specify the same amino acid, helps to mitigate the impact of mutations. This degeneracy allows for synonymous changes at the nucleotide level that do not alter the amino acid sequence, thus preserving protein function. Furthermore, the genetic code is nearly universal, reflecting a common origin of life on Earth, and reinforcing the significance of codon conservation in evolutionary biology.