ALPHA Guide a lineage through a changing world

Current breeder

Drag to orbit, scroll to zoom.

Selection pressure

Bias shifts the distribution of the next clutch. It does not guarantee an outcome, and the climate still gets a vote. At full tilt a slider moves the odds by about one and a half standard deviations — clearly felt, but still overlapping what you would have got anyway. You are weighting a dice roll, not placing an order.

Hip height sets a hard ceiling on speed. Short legs on a heavy body cannot be out-run by effort — but limbs are tissue, and tissue has to be fed.

Mass drives upkeep to the three-quarter power, so bigger costs more in total but less per kilogram. Size also buys reach and stride; it does not buy a thermal band.

A direct multiplier on upkeep, independent of mass. Raising it is the fastest route to starving in a lean year, and the fastest route out of a cold one.

The three are independent — nothing stops you pushing all of them at once, and nothing refunds you when the environment disagrees.

What kills an offspring

Checked in this order, before you get a vote. Three of the stats above are one half of these comparisons; the header carries the other half.

  1. Collapsed — the body plan cannot stand or move at all.
  2. Starved — upkeep exceeded the food available per head.
  3. Froze — the temperature fell below its tolerance.
  4. Overheated — the temperature rose above its tolerance.
  5. Eaten — escape speed fell below the predator's.

Offspring

Climate forecast

Weather is exact — it does not care how you are doing. The predator line is a projection: it assumes you keep improving at your recent rate. Change direction and you invalidate it, which is the point.

Fossil record

Every organism ever produced. Filled = survived, hollow = died before breeding. The heavy line is the surviving lineage.