How Genetically Similar Are We to Bananas?

Humans and bananas share a surprisingly large fraction of their DNA, with commonly cited estimates landing around 60 percent. That figure sounds absurd until you understand what it actually measures: not that you are mostly banana, but that the basic molecular toolkit for running a cell has been conserved across more than a billion years of evolution. The real story behind the number is more interesting than the number itself, because it reveals how much of your biology was already in place long before anything resembling an animal or a plant existed.

Where the 60 Percent Figure Comes From

When people say humans and bananas share 60 percent of their DNA, they are usually talking about a comparison of protein-coding genes. Your genome contains roughly 20,000 genes that code for proteins, and the banana genome contains around 36,500.

1Oxford Academic (Database). The Banana Genome Hub Many of those genes perform the same fundamental jobs in both species: copying DNA, producing energy, recycling damaged proteins, building a cell’s internal scaffolding, and responding to signals from the environment. When researchers align the amino acid sequences of these shared proteins, a large proportion match closely enough to be recognized as relatives of each other. That is what gives you the 60 percent figure, or something in that neighborhood depending on the alignment tool and the threshold used.

The percentage shifts depending on what you compare. If you lined up the entire raw DNA sequence of a human and a banana, including all the stretches that do not code for proteins, the overlap would be much lower. Most of the human genome is noncoding DNA, and a huge portion of the banana genome is, too. Those noncoding regions evolve faster and are far less similar between distant species. So the headline number reflects the conserved, functional core of both genomes rather than the genomes as a whole.

A Shared Ancestor More Than a Billion Years Old

The reason so much genetic material is shared between species as different as humans and bananas is that all complex life traces back to a single-celled ancestor. This organism, often called the last eukaryotic common ancestor, lived roughly 1.5 to 1.8 billion years ago, and about half of the gene families found in modern organisms were already present in it.

2Cell Genomics. A protein interactome for the last eukaryotic common ancestor illuminates the biochemical basis of modern genetic diseases Those genes formed the molecular systems that still power cells today, and many of them continue to influence genetic diseases and traits in humans.

The lineages leading to plants, animals, and fungi eventually went their separate ways. Analysis of amino acid sequences from dozens of enzymes places that split at roughly a billion years ago.

3PubMed. Determining divergence times of the major kingdoms of living organisms with a protein clock That same analysis found that plants are actually slightly more similar to animals than fungi are to animals, at least in terms of these core protein sequences. So despite how different a banana looks from a person, at the molecular level, the plant kingdom is not the most distant branch of complex life relative to us. Fungi are.

The Molecular Machinery We Genuinely Share

The shared DNA is not just an artifact of alignment algorithms. It corresponds to real biological systems that work in nearly identical ways in your cells and in a banana plant’s cells. A few examples bring this to life.

Tubulins are the proteins that form the internal scaffolding of a cell. Both plants and animals rely on networks of microtubules built from alpha-tubulin and beta-tubulin proteins, and these proteins are strikingly conserved across kingdoms. Animal, plant, fungal, and protist versions typically share more than 88 percent amino acid sequence similarity. The conservation is so strong that tubulin from one kingdom can co-assemble with tubulin from another, both in test tubes and in living cells.

4Plant Physiology. Differential Expansion and Expression of α- and β-Tubulin Gene Families in Populus

Actin filaments are another part of the cell’s internal skeleton, and the actin cytoskeleton plays vital roles in everything from cell division to intracellular transport. Research comparing actin’s function across species has confirmed that its core roles are conserved in organisms as different as humans and plants.

5PubMed Central. Exploring the Role of the Plant Actin Cytoskeleton: From Signaling to Cellular Functions

Then there is TOR, a master regulatory enzyme that coordinates how cells grow in response to nutrients and energy. TOR is conserved across yeasts, plants, animals, and humans, where it integrates nutrient and energy signals to promote cell growth and division.

6PubMed Central. The Role of Target of Rapamycin Signaling Networks in Plant Growth and Metabolism In humans, disruptions in TOR signaling are linked to cancer, diabetes, and aging. In plants, the same pathway controls growth and metabolic balance. The underlying logic is remarkably similar.

When Plant Genes Can Stand In for Human Ones

Perhaps the most vivid demonstration that shared DNA means something real comes from functional complementation experiments, where researchers take a gene from one kingdom and insert it into a totally different organism to see if it still works.

In one study, a plant enzyme called DlPar13, a parvulin-type protein from a plant, was put into yeast cells carrying a crippling mutation in their own version of the gene. When overexpressed, the plant protein was nearly as effective as the human version, hPin1, at rescuing the yeast from the effects of the mutation.

7PubMed. Functional replacement of the essential ESS1 in yeast by the plant parvulin DlPar13 Plant gene, human gene, both could fill the same slot in a yeast cell. That is the kind of conservation a billion years of evolution has not erased.

A more recent experiment went the other direction. Researchers took the human gene TMEM165, which is involved in transporting manganese inside cells, and inserted it into a mutant strain of the plant Arabidopsis that had lost its own version of the gene. The human protein was able to restore the plant’s photosynthesis efficiency, manganese binding, growth rate, and biomass production. A cyanobacterial version of the gene worked too, indicating that this manganese transport function is an ancient feature shared across plants, animals, and even bacteria.

8PubMed Central. Gene Replacement in Arabidopsis Reveals Manganese Transport as an Ancient Feature of Human, Plant and Cyanobacterial UPF0016 Proteins

These experiments make a point that a simple percentage cannot. It is one thing to say two genes look similar in a sequence alignment. It is another to show that one can physically replace the other in a living organism and keep that organism functioning.

Where the Similarity Breaks Down

The shared 60 percent is real, but the other 40 percent matters enormously, and even framing it as a clean split understates the differences. Humans and bananas diverged so long ago that the parts of the genome not under strong evolutionary pressure have drifted into unrecognizability. More fundamentally, each lineage has invented entire categories of biology the other lacks.

Plants photosynthesize. The entire chloroplast genome, the genes that build the light-harvesting machinery, the enzymes of the Calvin cycle, and the regulatory networks that coordinate photosynthesis with growth and development have no counterpart in human cells. Plants also build rigid cell walls from cellulose, an ability humans do not share. We have nervous systems, immune systems built around antibodies, and bones. None of those exist in bananas.

Even where the same gene family exists in both organisms, it can be deployed in wildly different ways. Plants cannot move to escape threats, so they evolved an extraordinary number of receptor genes to detect pathogens and environmental stress, often far exceeding the number humans carry for similar purposes. The banana genome, for instance, has undergone lineage-specific whole-genome duplications that expanded many gene families well beyond what is typical in animals. That is why a banana has over 36,000 protein-coding genes compared to a human’s roughly 20,000. More genes does not mean more complexity in the way people tend to imagine. It means evolution took a different path and solved different problems.

Epigenetics Across Kingdoms

Beyond the DNA sequence itself, both plants and animals use a layer of chemical modifications to control when and where genes are turned on or off. This layer, broadly called epigenetics, involves tagging DNA and the histone proteins that DNA wraps around. The tagging systems are surprisingly similar. DNA methylation and certain histone modifications, especially methylation at specific positions on histone tails, are among the best-characterized epigenetic marks in both plants and animals.

9PubMed Central. Epigenetic modifications in plants: an evolutionary perspective

Several of the enzymes responsible for placing or removing these marks are homologous across kingdoms.

10PubMed Central. Unexplored potentials of epigenetic mechanisms of plants and animals-theoretical considerations But there are also stark differences. Plants have an entire system of RNA-directed DNA methylation that animals do not use in the same way, and plants use DNA methylation far more extensively to silence transposable elements throughout their genomes. Animals, meanwhile, rely heavily on certain histone modifications for gene regulation during development that plants handle through different mechanisms. So even in the regulatory layer above the DNA, the theme is consistent: ancient shared foundations overlaid with kingdom-specific innovations.

Why the Percentage Changes Depending on How You Measure

One reason the “60 percent similar to a banana” claim circulates without a definitive source paper is that the number is genuinely squishy. It depends on choices the researcher makes at every step.

First, there is the question of what counts as “the same gene.” If you require that two genes share a specific ancestor, the threshold for calling them related matters a great deal. Set the similarity cutoff at 30 percent amino acid identity and you will find many more matches than at 50 percent. Both cutoffs are used in legitimate research for different purposes, and they yield different headline numbers.

Second, there is the question of what you are comparing. Whole-genome DNA alignment gives one answer, protein-coding gene comparison gives another, and comparison of individual protein families gives yet another. The tubulin proteins shared between plants and animals are over 88 percent identical, as noted earlier, while other proteins shared across kingdoms might be only 25 or 30 percent identical. Averaging across all shared proteins gives you one number, but it smears together highly conserved essential proteins and barely recognizable distant relatives.

Third, comparing genomes of different sizes introduces its own complications. The banana genome is about 523 megabases, while the human genome is roughly six times larger at around 3,200 megabases. Much of the size difference comes from noncoding DNA, repetitive elements, and structural features that do not correspond gene-to-gene. Any “percent similar” figure that does not specify which fraction of the genome it is talking about is ambiguous at best.

This does not make the comparison meaningless. It means the comparison is more nuanced than a single number can capture. A more precise way to say it: for roughly 60 percent of human protein-coding genes, you can find a recognizable counterpart in the banana genome, and those counterparts often work similarly enough that one can sometimes substitute for the other in a different organism.

How Bananas Compare to Other Classic Genome Comparisons

The banana comparison sounds surprising mostly because people underestimate how conserved the basic toolkit of life really is. But it fits neatly into a broader pattern. The degree of genetic similarity between humans and other species drops off in a fairly predictable way with evolutionary distance. Chimpanzees, our closest living relatives, share over 98 percent of their DNA with us. Mice share roughly 85 percent of protein-coding genes. Fruit flies and humans share enough core biology that fly research has been foundational for understanding human genetics and disease. Even yeast, a single-celled fungus, shares hundreds of genes with humans that are similar enough to be functionally interchangeable.

Bananas sit further along this continuum. The split between plants and animals happened roughly a billion years ago, compared to roughly 80 million years for the human-mouse split and about 6 million years for humans and chimps.

3PubMed. Determining divergence times of the major kingdoms of living organisms with a protein clock What is remarkable is not that the shared fraction dropped to 60 percent over a billion years, but that it stayed as high as it did. The genes that survived a billion years of independent evolution in both lineages are the ones that do the most essential, non-negotiable jobs in cell biology. Break them and the cell dies, so evolution kept them intact.

What the Comparison Actually Teaches Us

The banana statistic often gets trotted out as a fun fact or a gotcha to highlight the weirdness of genetics, but it carries a genuinely useful insight. Much of medicine and biology depends on the fact that model organisms share core genes with humans. The reason scientists can study cancer-relevant pathways in yeast, or test drug targets in fruit flies, or use the plant Arabidopsis to understand fundamental cell biology, is that the shared ancestry is real and functional. When roughly half the gene families in modern organisms were already present in our shared single-celled ancestor 1.5 billion years ago, even organisms that look nothing like us can serve as windows into how our own genes work.

2Cell Genomics. A protein interactome for the last eukaryotic common ancestor illuminates the biochemical basis of modern genetic diseases

The banana comparison also quietly corrects a common misconception about how genomes work. People tend to assume that a more complex organism must have more genes, or more unique genes, than a simpler one. Bananas have nearly twice as many protein-coding genes as humans. Complexity in organisms comes less from the raw number of genes and more from how those genes are regulated, spliced, and combined. The epigenetic and regulatory machinery layered on top of the genome creates most of the difference you see between a person and a piece of fruit, while the underlying gene catalog overlaps more than anyone would guess from appearances alone.