Alternative RNA splicing has been estimated to occur in more than 95% of multi-exon genes. Which of the following is not an evolutionary advantage of alternative RNA splicing?

• A. Alternative RNA splicing increases diversity without increasing genome size.
• B. Different protein variants can be expressed by the same gene in different tissues.
• C. Alternative RNA splicing creates shorter mRNA transcripts.
• D. Different protein variants can be expressed by the same gene during different stages of development.

Answer: (C)

Verified step by step guidance

1. Understand the concept of alternative RNA splicing: It is a process by which different combinations of exons are joined together to produce multiple mRNA variants from a single gene, leading to the production of different proteins.
2. Identify the evolutionary advantages of alternative RNA splicing: It allows for increased protein diversity without the need for a larger genome, enables tissue-specific protein expression, and allows for developmental stage-specific protein expression.
3. Analyze the given options: The first three options describe known advantages of alternative RNA splicing, such as increasing diversity without increasing genome size, and allowing for different protein variants in different tissues or developmental stages.
4. Evaluate the option 'Alternative RNA splicing creates shorter mRNA transcripts': This statement does not describe an evolutionary advantage. The length of mRNA transcripts is not directly related to the evolutionary benefits of alternative splicing.
5. Conclude that the correct answer is the option that does not describe an evolutionary advantage: 'Alternative RNA splicing creates shorter mRNA transcripts' is not an advantage, as the focus of alternative splicing is on diversity and adaptability rather than transcript length.