KEEP OUT
BY FREDERIC BROWN
With no more room left on Earth, and with Mars hangingup there empty of life, somebody hit on the plan ofstarting a colony on the Red Planet. It meant changingthe habits and physical structure of the immigrants, butthat worked out fine. In fact, every possible factor was covered—exceptone of the flaws of human nature....
Daptine is the secret of it.Adaptine, they called it first;then it got shortened to daptine.It let us adapt.
They explained it all to us whenwe were ten years old; I guess theythought we were too young tounderstand before then, althoughwe knew a lot of it already. Theytold us just after we landed onMars.
"You're home, children," theHead Teacher told us after we hadgone into the glassite dome they'dbuilt for us there. And he told usthere'd be a special lecture for usthat evening, an important onethat we must all attend.
And that evening he told us thewhole story and the whys andwherefores. He stood up before us.He had to wear a heated spacesuit and helmet, of course, becausethe temperature in the domewas comfortable for us but alreadyfreezing cold for him and the airwas already too thin for him tobreathe. His voice came to us byradio from inside his helmet.
"Children," he said, "you arehome. This is Mars, the planet onwhich you will spend the rest ofyour lives. You are Martians, thefirst Martians. You have livedfive years on Earth and anotherfive in space. Now you will spendten years, until you are adults,in this dome, although toward theend of that time you will be allowedto spend increasingly longperiods outdoors.
"Then you will go forth andmake your own homes, live yourown lives, as Martians. You willintermarry and your children willbreed true. They too will beMartians.
"It is time you were told thehistory of this great experiment ofwhich each of you is a part."
Then he told us.
Man, he said, had first reachedMars in 1985. It had been uninhabitedby intelligent life (there isplenty of plant life and a fewvarieties of non-flying insects) andhe had found it by terrestrialstandards uninhabitable. Mancould survive on Mars only byliving inside glassite domes andwearing space suits when he wentoutside of them. Except by dayin the warmer seasons it was toocold for him. The air was too thinfor him to breathe and long exposureto sunlight—less filteredof rays harmful to him than onEarth because of the lesser atmosphere—couldkill him. Theplants were chemically alien tohim and he could not eat them;he had to bring all his food fromEarth or grow it in hydroponictanks.
For fifty years he had tried tocolonize Mars and all his effortshad failed. Besides this domewhich had been built for us therewas only one other outpost, anotherglassite dome much smallerand less than a mile away.
It had looked as though mankindcould never spread to theother planets of the solar systembesides Earth for of all of themMars was the least inhospitable;if he couldn't live here there wasno use even trying to colonize theothers.
And then, in 2034, thirty yearsago, a brilliant biochemist namedWaymoth had discovered daptine.A miracle drug that worked noton the animal or person to whomit was given, but on the progeny heconceived during a limited periodof time after inoculation.
It gave his progeny almostlimitless adaptability to changingconditions, provided the changeswere made gradually.
Dr. Waymoth had i