fix water migration
optimize more
roughly 6.5% of thread lifespan is spent waiting at a thread barrier
reduce non-threaded parts of Tribe_Actions()
*cleanup dirty code

*map wrap for movements
*total_runtime
*climate change
*elevation climate effects
*temperature/climate regions based on equatorial distance

6.49 K(°C)/1,000 m (3.56 °F or 1.98 K(°C)/1,000 Ft)
from sea level to 11 km (36,090 ft). 
From 11 km (36,090 ft or 6.8 mi) up to 20 km (65,620 ft or 12.4 mi), 
the constant temperature is -56.5 °C (-69.7 °F), which is the lowest assumed temperature in the ISA.

-2 to +2C gradual temp cycles for 10K years  for now 

food depletion / abundance
predator

*sea travel (scarse displacement)
*state save/load
crc check on state load
age based range for reproduction
*var to limit 1 reproduction per tribe
*better stats (species counts, current life totals)
*better threading
~better interface
fractional texturing

might never do:
continental drift
above sea level bodies of water
find/implement data on ocean/wind currents
vegetation