What are the sources for new genes in species?

Question

organic biology

Answer 1

New genes come from mutations

Causes of mutations
- radiation
- exposure to mutagens
- DNA replication error
- transposons
These mutations are completely random, and may be good, bad, or have absolutely no effect. Ones that don't kill the organism can potentially be passed onto its offspring, and "good" genes will continue to survive in the gene pool while "bad" ones will die off.

Genes can also be added to an organism in vitro through vectors containing plasmids.

Answer 2

In theory, new genes result from mutations which change the gene product. Recent attention has focused on mutations which alter the regulatory sequences of genes rather than the portion which codes for the actual protein.

In addition, it has been discovered that a certain amount of 'junk' DNA may consist of inactive genes that can be re-activated by mutation to the activating portion. The insertion or removal of integrated retroviral sequences may also result in mutations without the actual creation of new genes. Similarly, somatic recombination of chromosomal segments may result in genetic changes that do not require the development of 'new' genes.

Answer 3

Duplications that diverge. Genes are occasionally duplicated. As they mutate, new variations can form while the old are preserved.