Science
by Siddhartha Mukherjee
What gets passed down, and how?
Siddhartha Mukherjee, a cancer doctor, has a personal reason to ask. Serious mental illness runs through his father's family, including two uncles and a cousin. The Gene tells how we learned what heredity is made of, and asks what to do now that we can read and rewrite it.
Hear a sample · read by Laura
In the 1850s and 60s, Gregor Mendel, a friar in what's now the Czech Republic, crossed thousands of pea plants. Traits like flower colour, he found, pass on in separate units that don't blend, and can skip a generation. Darwin, whose theory needed that answer, died without knowing it.
In the 1910s, Thomas Hunt Morgan's fruit flies showed genes sit on chromosomes. In 1944, experiments suggested genes were made of DNA. In 1953, using X-ray images from Rosalind Franklin's lab, James Watson and Francis Crick found its shape, a double helix that unzips so each strand can be copied.
A few diseases come from a single faulty gene. Most traits, from height to the risk of schizophrenia, are nudged by many genes at once, and the outcome also depends on surroundings and plain chance. Identical twins share their genes, yet can still turn out differently.
By the early 2000s, scientists had read nearly the whole human genome. Then came CRISPR, a tool that can edit DNA far more precisely than before. Mukherjee urges caution. He'd consider changing a gene that almost always causes severe suffering, and warns against editing for traits we simply prefer.
His family
Mental illness runs through Mukherjee's own family, which is part of why he wrote the book.
Mendel
Mendel's pea plants showed that traits pass down in separate units, which we now call genes.
Eugenics
Eugenics took early gene science and used it to excuse cruelty to real people.
Double helix
DNA is a double helix, and its code is copied each time a cell divides.
Genes and life
Genes and surroundings work together. Very few traits come from a single gene.
A story from the book
In 1927, the US Supreme Court let Virginia sterilise Carrie Buck against her will, claiming she was mentally deficient and would pass it on. By most accounts she wasn't. Mukherjee uses her case to show how eugenics, then popular in Britain and America, dressed prejudice up as science.
Hot take · true or myth?
Darwin knew how traits were passed from parent to child.
Myth. Darwin never found a working theory of heredity. His guess, that tiny particles from every part of the body gathered in the sex cells, was wrong. Mendel's answer existed, but Darwin never saw it.
One thing to try
This week, ask an older relative about the health of their parents and grandparents. Write down anything that turns up more than once, like heart disease or diabetes. Mukherjee's story starts with his own family, and a family history is still one of the first things a doctor asks for.
Knotd has the key ideas from 250+ non-fiction books, each in a few minutes, in plain words. The Gene comes with a Hot Take round and a Name That Idea round to make it stick.
Get the whole book on KnotdOpen in the appWhat gets passed down, and how? Siddhartha Mukherjee, a cancer doctor, has a personal reason to ask. Serious mental illness runs through his father's family, including two uncles and a cousin. The Gene tells how we learned what heredity is made of, and asks what to do now that we can read and rewrite it.
The friar and his peas; From idea to molecule; One gene, one trait is rare; Reading and rewriting.
This week, ask an older relative about the health of their parents and grandparents. Write down anything that turns up more than once, like heart disease or diabetes. Mukherjee's story starts with his own family, and a family history is still one of the first things a doctor asks for.
Yes. Knotd has the key ideas from The Gene in a few minutes, in plain words, plus a Hot Take round and a Name That Idea round to test them. It's one of 250+ non-fiction books in the app.
