FACT #3 — Humans are surprisingly closely related to fungi
If you zoom out far enough on the family tree of life, fungi are not “basically plants.” They’re actually closer to animals (including us) than they are to plants. Scientists group animals and fungi together in a big branch called Opisthokonta, which is one reason fungi show up in biology and medicine way more than most people expect. https://asm.org/articles/2021/january/three-reasons-fungi-are-not-plants
So what does “we share DNA with fungi” really mean? It doesn’t mean half of your DNA is “mushroom DNA.” It means that when scientists compare genes between species, they often find matching or related genes (called orthologs) that came from the same ancient ancestor and still do similar jobs today. That’s how researchers measure how “related” two living things are at the genetic level. https://pmc.ncbi.nlm.nih.gov/articles/PMC9194483/
Here’s a solid, verifiable number: one peer-reviewed genetics review explains that budding yeast (a fungus) shares 2,146 orthologs with humans, and because humans sometimes have extra copies of genes, humans share 3,942 genes with yeast in that same comparison system. That’s thousands of shared genes between you and a fungus, even though we look nothing alike. https://pmc.ncbi.nlm.nih.gov/articles/PMC9194483/
You’ll also see another way scientists summarize this: one research paper states that yeast has about 23% homologous genes to humans (homologs = genes related by ancestry). That’s a real, measured “share” number you can point to without hype, and it helps explain why fungi are such a powerful model for understanding human biology. https://pmc.ncbi.nlm.nih.gov/articles/PMC5525645/
And it gets even wilder: scientists have tested whether some human genes can literally do the job of yeast genes. In a major study, researchers replaced 414 essential yeast genes with their human versions, and found that nearly half (47%) of those yeast genes could be “humanized” and still work well enough to keep the yeast alive. That doesn’t mean we’re half fungus—it means deep parts of life’s machinery are so conserved that human versions can sometimes run the same biological “hardware.” https://pmc.ncbi.nlm.nih.gov/articles/PMC4718922/
