The codons that code for alanine in a potato beetle are the same as those that code for alanine in mackerel and humans. This evidence best supports the idea that -(D) different species share components of the genetic code
Explanation:
Evaluating the other options given
A.humans and fish evolved from insects -This option is incorrect as human and fish did not have a common ancestors.
B. different species synthesize the same proteins :No this statement also is not the correct option
C. insects, fish, and humans express the same genes-The expressed genes cannot be same for different species
Hence the correct answer is
The codons that code for alanine in a potato beetle are the same as those that code for alanine in mackerel and humans. This evidence best supports the idea that -(D) different species share components of the genetic code(As the genetic code is said to be universal