Roxanne Khamsi: We Are All Genetic Mosaics

“You are a slightly different genetic version of yourself today from yesterday, and will be different yet again tomorrow.”—Roxanne Khamsi

“Each neuron really is a beautiful and unique snowflake”—Ed Yong

Roxanne Khamsi is one of the leading life science journalists, a contributing writer at The Atlantic, recognized with multiple awards for notable publications. Her new book is entitled BEYOND INHERITANCE. It tells the story about us all being genetic mosaics, chock full of somatic (acquired) mutations, and the implications of those mutations for our health. The myth of a single genome, carbon copy, master blueprint, but instead a dynamic, shifting mosaic in constant internal evolution.

And here’s the back cover. I was delighted to endorse this book, and reread it to prepare for our podcast. It’s extraordinary and mind-bending.

Here are the topics we covered:

—The Math. 330 billion cells of our ~37 trillion turnover each day, which yields trillions of mutations per day.

—Cellular competition. Winners and losers of an “endoevolution,” Darwinian selection inside us whereby healthy or super-fit mutated cells can crowd out the unfit ones.

This was theorized in 1881 in a book THE STRUGGLE OF PARTS, by Wilhelm Roux

which led to Friedrich Nietzsche’s famous quote “Uniformity is pure delirium.”

—Single-cell sequencing. How this field catapulted forward owing to the ability to zoom in on genomic mutations at the cellular level.

—Cancer chemotherapy overkill. The routine scorched earth, carpet bombing approach can promote resistance and deleterious mutations, leading to an adaptive strategy of leaving some cancer cells behind, as has been shown to be effective in prostate cancer for improving survival.

—The immune system somatic hypermutation. B cells have the theoretical capacity to produce 1 quintillion unique antibodies (a million trillion). If this weren’t possible, we could die from a common cold. In the Covid pandemic, even before the Omicron variant appeared, Covid booster shots induced hundreds of unique antibodies with neutralization capacity against Omicron. The anticipatory “Red Queen” effect.