“The last thing we want is a nasty divorce between humans and superintelligent machines, for that would certainly spell the end of the human race.”

BBC (2 December 2014) http://www.bbc.com/news/technology-30290540

The Transhumanism Handbook, 2019

Source: Sceptical Essays

Cited in Tim Flannery, Atmosphere of Hope. Solutions to the Climate Crisis, Penguin Books, 2015, page 81 ISBN 9780141981048.
Other

All Gall Is Divided (1952)

1950s, The Russell-Einstein Manifesto (1955)
Context: Here, then, is the problem which we present to you, stark and dreadful and inescapable: Shall we put an end to the human race; or shall mankind renounce war? People will not face this alternative because it is so difficult to abolish war.
The abolition of war will demand distasteful limitations of national sovereignty. But what perhaps impedes understanding of the situation more than anything else is that the term "mankind" feels vague and abstract. People scarcely realize in imagination that the danger is to themselves and their children and their grandchildren, and not only to a dimly apprehended humanity. They can scarcely bring themselves to grasp that they, individually, and those whom they love are in imminent danger of perishing agonizingly. And so they hope that perhaps war may be allowed to continue provided modern weapons are prohibited.
This hope is illusory. Whatever agreements not to use H-bombs had been reached in time of peace, they would no longer be considered binding in time of war, and both sides would set to work to manufacture H-bombs as soon as war broke out, for, if one side manufactured the bombs and the other did not, the side that manufactured them would inevitably be victorious.

"One Half of a Manifesto," The New Humanists: Science at the Edge (2003)

Television interview on March 24, 1958, as quoted in The United States in World Affairs (1959), p. 12
1950s

Spark (2014)