���˿���

There are two types of gene transfer:

• vertical gene transfer - when genes are transferred down generations, ie from parent to offspring as a result of sexual or asexual reproduction
• horizontal gene transfer - when genes are transferred across from an individual to others in the same generation. This does not occur due to reproduction.

Prokaryotes such as bacteria can exchange genetic information through horizontal gene transfer. This method of gene transfer is instantaneous and therefore can result in faster evolutionary change than in organisms that only use vertical transfer. Resistance to antibiotics has spread widely in the bacterial population due to the horizontal transfer of plasmids that carry these resistance genes.