Pick how many civilizations, how big they start and how much land they
get. The land is valleys, each with its own climate, and every
civilization starts in one, built for its weather. Every creature
carries six genes (speed, size, sight, aggression, the climate it
likes, and a neutral one that only drifts), and parents pass each on
whole, like an allele, with a small mutation. When a population comes
apart into two groups too different to interbreed, a new species is
born, and named the way naturalists name them: its lineage, then what
sets it apart, so the fierce ones that split from the Aru are
Aru ferox. The chronicle says why each split happened and how
each species' last members died.
Every creature is drawn from its own genes (the key under the map shows
how): size is size, faster ones are longer, sharper-eyed ones have
longer antennae, fiercer ones grow a horn, cold-built ones grow fur,
and the neutral gene shifts its colour, so drifting families slowly
change hue. Click one to see it beside the average of its species. Young ones start small. One second is one year at ×1. At ×1000, as fast as your machine can manage (the readout shows the real rate), tens of thousands of years pass a minute.
Click a creature to follow it. The shading on the map is food.
Throw meteors, plagues, droughts and wars yourself, and choose which
of them also happen by themselves. Every meteor is remembered, with
its size and its toll; a big one's dust cools the whole land for a
generation, and its crater takes a century to heal. Hold rain over
a valley and it grows richer, until it floods; dry one out and watch
its creatures leave, or die. Warm the climate or cool it and it
changes over decades, not overnight: creatures built for the old
weather adapt, grow or shed their fur, move, or die out. The chart's
climate view shows them chasing the land's temperature.
space pause · n new world · p plague · d drought · g plenty · w war · h warming · c cooling · f follow · m meteor · r rain · y dry
Written in Dart, compiled to JavaScript, baked into this page, sounds included, synthesized as they play. Creatures live 55 to 80 years. Real speciation takes far longer; here a thousand years will usually do it.