When the human genome was sequenced in 2003, genomics comparisons showed that humans share DNA not only with primates, but also with bananas, chickens and even fruit flies.
Chimpanzee (Pan troglodytes) - ~96% DNA similarities
Chimpanzees are our closest living relatives, therefore they provide important insights into the things that differentiate us from chimpanzees, including the genes associated with developing and regulating the brain.
Chicken (Gallus gallus) - ~60% DNA similarities
Many genes involved in the immune system (interleukins) and bone growth are evolutionarily related between birds and mammals.
Banana (Musa acuminata) - > 60% DNA similarities
There are many “housekeeping” genes that perform basic functions for all cellular life. Examples include the genes that are responsible for DNA replication and cell division.
Fruit Fly (Drosophila melanogaster) - ~60% DNA similarities
Fruit flies are extremely valuable as research models for human disease because 75% of the disease-related genes in humans have related genes that are found in fruit flies.
What is the Reason for Sharing a Large Amount of Our DNA?
Every species originated from a common ancestor known as LUCA (Last Universal Common Ancestor). Most of the primary genetic sequences have remained unchanged through time because they are necessary for life itself.
Why Genetic Similarities are Important to Medicine
Scientists use genetic similarities to:
Find (diagnose) genetic causes of diseases
Build better models for understanding diseases
Have a better understanding of evolution
Find new targets for therapies
MBH/PS