Discovering Life’s Story: The Birth of Genetics

Can we crack the code to life itself? In the third volume in the Discovering Life’s Story series, scientists compete to decipher the genetic blueprint behind all life on earth.

It’s the dawn of the twentieth century. Darwin has theorized that traits get passed down through generations, and Mendel has come up with a mathematical formula that predicts how traits reappear over time. But a key mystery remains: is there a recipe for living beings? If there is, where is it hidden? With the help of powerful new microscopes and x-rays, scientists peer ever closer into cells, searching for answers. They find chromosomes, tight coils of DNA, mutations that introduce new variations in species, and proteins that dictate how living things function. Walter Sutton observes that chromosomes come in pairs. Nettie Stevens discovers the X and Y chromosomes that define biological gender. And Rosalind Franklin, James Watson, and Francis Crick compete to be the first to understand DNA’s structure. But is it proteins or DNA that carry the secrets to life’s blueprint?


In Birth of Genetics, Joy Hakim, author of the best-selling series A History of US, continues charting the path of human discovery as scientists race to unravel our genes and the mysteries they hold.Hakim gives the story rich historical context. . . . This book offers a clear, vivid, and detailed look at the birth of genetics, and the many photographs and illustrations make the story come alive.
—School Library Journal

The frequent illustrations, bold design, chapter heading quotations, and approachable writing style provide teen appeal. . . . Hakim presents the big-picture ideas clearly and closes by setting the stage for the next series entry. Rivetingly told, with an eye to inclusive coverage and collaborative efforts.
—Kirkus ReviewsJoy Hakim is the best-selling author of A History of US, a ten-volume history of the United States that has sold over three million copies. She also wrote the much-lauded Story of Science series (Smithsonian) that includes Einstein Adds a New Dimension. The author of the first two books in the Discovering Life’s Story series, Biology’s Beginnings and Evolution of an Idea, Joy Hakim has worked as a teacher, newspaper writer, and editor and currently lives in Maryland.Introduction: Here Come the Moderns
When Charles Darwin dies, in 1882, he leaves much to discover.
His work dramatically shifts our perspectives of life on Earth and our place in it. According to Darwin’s evolutionary theories, the organisms best adapted to their surroundings are the most likely to survive. That concept becomes known as “survival of the fittest.” But at the dawn of the twentieth century, many questions remain unanswered and great changes in our understanding of evolution are on the horizon. Soon biologists will see things that are smaller in size and larger in significance than even Darwin could imagine.
Granted, it is the atom and the vastness of outer space that capture most public attention during this time. Albert Einstein, Niels Bohr, Marie Curie, and later Stephen Hawking are star physicists who change the way we understand the world around us. Trips to the moon and computers on desktops are two by-products of the new ways of thinking that come with modern physics.
But the twentieth century’s biologists will grapple with a fundamental question: What is it inside each of us that makes us unique? Philosophers and clerics have had thoughts on this question throughout recorded time, but in 1900, with the twentieth century looming, the question has not yet been answered. Scientific tools—chiefly microscopes—are not yet powerful enough to solve what has become one of the world’s great mysteries. The clues are just too tiny to see.
Discovering the truth will take persistence, invention, and scholarship as scientists slowly build on one another’s work. This quest will be helped by technological marvels and interrupted by terrible wars. It will take place at a time of astonishing societal change.
In 1879, Walther Flemming (1843–1905), a German scientist who served as a military physician during the Franco-Prussian War, peers through a microscope. Flemming is determined to figure out what happens when a cell, the basic structure found in all life-forms, divides, resulting in two new cells. He notices a cluster of threadlike material that appears just as a cell begins to divide. When the cell splits, so too do these tiny wisps, separating themselves equally between both sides.
This observation feels to Flemming like a critical clue. Over the next few years, he centers his studies around these threads, coloring them with dye made from coal tar to better track their movements. As microscopes improve, the threads come into sharper relief and are eventually named chromosomes, from the Latin words for color (chroma) and body (soma).
But though they have a name, not everyone agrees that chromosomes matter. A spirited debate unfolds. One prominent Swiss botanist, Carl von Nägeli, dismisses their importance, theorizing that something he calls the “idioplasm” must be directing hereditary changes. A German biologist, Richard Altmann, believes tiny mechanisms within cells that he calls “bioblasts” are more important. But by the end of the nineteenth century, many scientists share Flemming’s belief that chromosomes must play a significant role in transmitting genetic information during cell division and reproduction: How could something that suddenly appears while the process is underway not be vital to its success?
And they are right: the key is in the chromosome, and unlocking its secrets will consume life science for the next half of the century.
And what a century it is! The world is changing at a rapid clip. In 1913, Henry Ford develops a way to mass-produce his Model T automobile, transforming the way we travel. His groundbreaking assembly-line system—where workers line up alongside moving conveyor belts, each charged with a different task—changes the way all sorts of goods are produced, making them more affordable. Soon enough, middle-class citizens in many countries are able to afford not only cars but also flushing toilets, washing machines, refrigerators, and other useful things.
Big ideas percolate throughout society. An abundance of inventors, experimenters, artists, writers, and financiers are informed and inspired by the new knowledge exploding around them. Radio and TV don’t exist when the century begins, but print is cheap, and the “penny press” flourishes. Information has value and is in demand; newsstand displays are lined with newspapers and magazines.
It is not only the United States that is experiencing a shift toward a more modern world. The Eiffel Tower is completed in Paris in 1889. The Panama Canal, a shipping route connecting the Atlantic and Pacific Oceans, is under construction. The Kodak camera, introduced in 1888, uses rolled film rather than unwieldy glass plates, making photography more accessible. Marie Curie, a Polish-born physicist, is conducting pioneering research on radioactivity in Paris. In Japan in 1904, the physicist Hantaro Nagaoka develops new theories about the atom, likening its structure to that of a solar system.
Some of the changes grow out of mathematical roots planted by England’s James Clerk Maxwell,