I have heard my entire life that humans share 50% of our genes with a banana. When I look online, I see that many famous scientists such as Steve Jones have said this. However, no one has provided a source for this information. Can you direct me to a scientific study that has shown this? Perhaps they mean that humans generally share half of their genes with most plants?


Your entire life! I’ve have had a look for an authoritative source and can’t find one - maybe someone else will have more luck! There are lots of comments of this type attributed to Steve Jones and others that go back to 2000 or earlier (and are continually recycled), which is interesting given that as far as I can see the first draft of a banana genome was published in 2012 (see - http://www.nature.com/nature/journal/v4 … 241.html). If there is a value of around 50% gene-share between banana and humans, it would be interesting to know how the DNA was actually compared! Presumably by ‘genes’ people are referring to the predicted protein-coding genes, approx 36,000 in the banana genome which is more than that predicted in humans.

There will obviously be some banana (or plant)-specific genes, and bananas won’t be ‘special’ i.e., you would suspect a high degree of nucleotide identity between human and plant house-keeping genes (e.g., involved in basic cell machinery such as transcription and translation). I’ve seen values of around 40-50% gene match between drosophila (fruit fly; around 14,000 genes) and humans (e.g., see - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3082451/) - in this case I think people are generally referring to the overall identity at the nucleotide level between homologs (not all genes!). I doubt bananas will outdo flies at this level!