Question

Compare and contrast the process by which genes are born and the process by which genes die. include at least one way in which these two processes are the same, and one way in which they are different.

Answer 1

Ans . Both the birth and death of genes can be caused by DNA mutations. The birth of genes can occur through the duplication of existing gene followed by a mutation that results in a new function for that gene. The death of genes can occur through mutations that destroy the function of a gene.

Gene birth :- Gene duplication is the essential source of new genes with new or altered functions. When duplicate is fixed in the genome and is functionally preserved by natural selection , the new born gene may diverge under two primary scenarios.

The first classic scenario is neofunctionalization, in which duplicate evolves towards a new function that results in a sequence that is significantly divergent from its ancestral gene.

The alternative scenario is subfunctionalization, in which ancestral functions are partitioned between new duplicates in spatial or temporal expression patterns. In all cases, the the origin of a new gene can only be demonstrated when its place of gene birth is localized in the genome.

Gene death :- It is usually caused by introducing any changes that lead to a premature stop codon. Now, with the availability of complete animal genome sequences, it is possible to test hypotheses concerning gene death by searching for the trace of a pseudogene in certain species. If the pseudogene can be localized in the corresponding position of a conserved genomic region, the it can be concluded that gene pseudogenization has occured.