Free Shadows of Forgotten Ancestors by Carl Sagan, Ann Druyan

solution of life’s greatest mystery would be snatched away. If science were in the business of conferring sainthood, the conduct of Darwin and Wallace towards one another would have earned it for them both. Darwin wrote a letter of hearty congratulation to Wallace in which he mentioned how long he’d been working on the same problem.
    Darwin’s friends Huxley and Hooker prodded him to quit stalling and write the paper that would make an ironclad case for evolution. He complied and was nearing its completion in 1858, while Wallace, now in Indonesia and sick with malaria, tossed and turned, grappling with the question “Why do some die and some live?” 22 Emerging from his stupor, he understood natural selection. He wrote “On the Tendency of Varieties to Depart Indefinitely from the Original Type” and promptly mailed it to Darwin, asking him to use his judgment aboutwhat should be done with it. Darwin was distressed to see how very close Wallace’s work was to his own writings of 1839 and 1842. In 1844 he had combined them into an essay, but it remained unpublished. Darwin turned to his friends for guidance on how to deal ethically with this dilemma. Hooker and Lyell came up with a wise solution: Present both the Wallace paper and a version of Darwin’s unpublished 1844 essay at the next meeting of the Linnaean Society and publish them together in the Society’s
Proceedings
. 23 Thereafter, Wallace always spoke of evolution as being Darwin’s theory and Darwin always credited Wallace with its independent discovery. Darwin now applied himself to the task of writing the book that would cause so much trouble.
    On November 24, 1859,
The Origin of Species
was published. The first edition of 1,250 copies was snapped up by the booksellers. Darwin had been careful to make only one reference to humans in the whole book: “Light will be thrown on the origin of man and his history.” 24 Anything more from his pen on this delicate matter would have to wait another twelve years, for the publication of
The Descent of Man
. His restraint fooled no one. Given its formidable armamentarium of data, there could be no reconciling
The Origin
with a literal rendition of Genesis.

Chapter 4
     

A GOSPEL OF DIRT
     

I detest all systems that depreciate human
nature. If it be a delusion that there is
something in the constitution of man that is
venerable and worthy of its author, let me live
and die in that delusion, rather than have my
eyes opened to see my species in a humiliating
and disgusting light. Every good man feels his
indignation rise against those who disparage his
kindred
or his
country;
why should it not rise
against those who disparage his
kind?
    THOMAS REID
letter of 1775 1
     
    When I view all beings not as special creations,
but as the lineal descendants of some few
beings which lived long before the first bed of
the Cambrian [geological] system was
deposited, they seem to me to become
ennobled.
    CHARLES DARWIN
The Origin of Species , Chapter XV 2
     

M ankind has conducted an experiment of gigantic proportions,” Darwin wrote in
The Origin of Species
. He was struck by the success of “husbandry,” as it is tellingly called, in generating new varieties of animals and plants useful for humans. Nature provides the varieties and we select who shall reproduce, which traits we want preferentially to propagate into future generations. By transferring pollen from flower to flower with a camel’s hair brush, or by letting the stallion in with the mare, humans take it upon themselves to determine who shall mate with whom. Indigestible crops, weakling horses, scrawny turkeys, sheep with knotty coats, and cows that are grudging with their milk are discouraged from reproducing. Generation after generation, by cumulative selection, humans impress their interests on the heredity of the plants and animals whose breeding they control. But Nature, too, selects those plants and animals which by its lights happen to be more