So over the weekend the Weelanders finally acquired the means to share genetic matter, and sharing genetic matter seems to be a more reliable way to create a healthy population…

After some tweaking and slimming down of the Basic-c2 genome, I made two new versions of it.  The first, a000, was basically just a copy–this is the “asexual” basic genome.  The second, s000, was identical in all respects except the _ReproMethod gene was set to 1 (sexual) instead of 0 (asexual).

Then just for grins, I started the simlation with a mixture of a000's and s000's (36 of each).  The sim ran for 2,482 ticks when the last creature died.  I expected the sexual creatures to take over and the asexual ones to die out, but it didn't quite work out the way I expected.  First of all, if a Weelander has sexual reproduction turned on, it doesn't matter if the target mate does.  An s000 can exchange genetic matter with any compatible genome (same number of chromosomes, same chromosome names).  So really the presence of the s000 genome *helped* the a000 genome.  How?  By creating a hybrid genome (called “i” in my simulation) that was half-s and half-a. 

When an “i” is born, it carries one gene that says “reproduce sexually”, and another that says “reproduce asexually”.  The one that is active is decided randomly at birth, so some of the hybrids just copy themselves, while others seek out a partner.  Apart from this one gene s000 and a000 (and the hybrid i) are all identical.  So when i mates with i, the offspring is either another i, or a new a000, or a new s000.  Thus the hybrid organism can produce more organisms of different types! When i mates with a000, the offspring is 50% likely to be an a000.  When i mates with s000, the offspring is 50% likely to be an s000.

Nonetheless, looking at the numbers, one might conclude that the asexual method of reproduction is better for a species.  Check it out:

As you can see s000 (the green line) starts strong, but evetually peters out about two thirds of the way into the sim.  a000 (the blue line) seems to do more poorly at the beginning, but is still there when s000 dries up, and in fact the last creature alive on the grid is an a000.  The hybrid (red) appears to have more staying power than s000, but it too disappears before a000 does.

(Note the little reappearance of s000 around tick 1650!  Back from the dead?  Nope, just the offspring of two hybrids mating!)

The thick purple line is the count of the number of different genomes alive on the grid at each tick (the diversity).  As you can see, once the activity of s000 and i have peaked, the diversity reaches its peak and slowly tapers off during the decline in the population.

Looking at this graph one might think that asexuality is the winner.  But not so fast!  First of all, when an asexual creature reproduces, it makes a copy of itself.  When a sexual creature reproduces, it makes a new creature.  So it is normal and expected for s000 to fade out faster than a000.  The important questions are, (1) what about s000's genetic matter, is it surviving in the overall population, and (2) is it helping the overall population?

The genome report holds the answer:

Most successful genomes:
Genome s000 - 307 births.  Lineage:
Genome a000 - 363 births.  Lineage:
Genome i - 336 births.  Lineage:  --> s000 + a000
Genome 0 - 25 births.  Lineage:  --> s000 + s000
Genome q - 23 births.  Lineage:  --> i + i
Genome s - 25 births.  Lineage:  --> 0 + i
Genome t - 33 births.  Lineage:  --> a000
Genome Q - 43 births.  Lineage:  --> s000 + q
Genome x - 30 births.  Lineage:  --> Q + s000
Genome J - 37 births.  Lineage:  --> s000 + t
Genome K - 22 births.  Lineage:  --> i + J

Although a000 enjoys a 16% lead over s000 in total number of births (some of which are the result of pairs of i's mating) it's easy to see who's genetic material had the most impact on the population.  Of the 11 successful genomes on the list, all but 2 reproduce sexually.  The only asexual reproducers that made the grade were ”t”, a descendant of a000, and a000 itself.

 Every other creature had a pair of parents.  That's 848 creatures the product of sexual reproduction, to 396 from asexual reproduction.  Sex wins, folks.