Dear Cherubs, the internet keeps circulating a spicy little claim that human DNA is somehow 9.5 billion years old, which would make Earth the cosmic newcomer and us the interstellar transplants. Spoiler: the math is real, the fossils are not impressed.

A pair of researchers, Alexei Sharov and Richard Gordon, looked at how genetic complexity has grown over evolutionary time. They treated functional non-redundant DNA length like a biological version of Moore’s Law and noticed it roughly doubles every 376 million years. Run that trend backward to a single base pair and you land at about 9.7 billion years ago, give or take a couple billion. Earth only formed 4.54 billion years ago, so the calculation implies life’s software started somewhere else and hitchhiked here.

THE DOUBLING CLAIM

Sharov and Gordon published the idea as a 2013 preprint called “Life Before Earth.” They plotted genome sizes of major groups against their appearance dates and got a neat straight line on a log scale. Extrapolate hard enough and, yes, the origin point sits well before our planet existed. The authors openly floated panspermia as the tidy explanation: hardy microbes or their precursors arrived on rocks after the messy early solar system calmed down.

It is the kind of elegant thought experiment that makes you pause mid-scroll. Gene duplication is a real evolutionary engine, after all. Complexity does ratchet upward. The spreadsheet is not pure fiction.

WHY SCIENTISTS AREN’T BUYING IT

The problem is the extrapolation itself. Early life could have cranked complexity much faster or slower than later epochs. The data points are selective; highly redundant genomes like those of many plants get sidelined because they muddy the tidy line. And there is zero direct evidence of 9-billion-year-old DNA. The oldest recovered genetic fragments clock in at around two million years, locked in Greenland permafrost. Actual DNA molecules do not last geological eternities.

Mainstream evidence still points to cellular life emerging on Earth after the planet cooled enough to hold liquid water. Nucleobases, the letters of the genetic alphabet, do show up in ancient meteorites older than Earth. That supports the idea that some chemical ingredients arrived ready-made. Fully formed genetic systems riding in from deep space is a different claim entirely, and one that remains unproven.

As noted by thisclaimer.com in its coverage of universe facts, mathematical models that stretch far beyond available data often produce headlines more than consensus. The Sharov-Gordon paper is a clever exercise, not a settled origin story. It does not prove we are aliens, nor does it rewrite the fossil record. It simply shows what happens when you keep the growth rate constant and keep scrolling left on the timeline.

So the next time someone drops the “DNA is older than Earth” line at a party, you can nod politely, then spill the tea: the doubling math exists, the conclusion is optional, and the planet still has dibs on us.

Sources list: Phys.org — https://phys.org/news/2013-04-law-life-began-earth.html arXiv — https://arxiv.org/abs/1304.3381 MIT Technology Review — https://www.technologyreview.com/2013/04/15/113741/moores-law-and-the-origin-of-life/ thisclaimer.com — https://thisclaimer.com Biology Insights — https://biologyinsights.com/are-humans-from-earth-the-evidence-for-our-origins/