sub fitnessCalculation{ ... }
sub mixAndMutate{ ... }

my @data = readData();

my @generation = genRandomGeneration( 1000 );

while( 1 ) {
    $_->score = fitnessCalculation( $_ ) for @generation;

    @generation = ( sort @generation ) [ 0 .. 200 ];

    last if $generation[ 0 ]->score > $targetScore;

    push @generation, mixAndMutate( @generation );
} 

report $generation[ 0 ];

##</code><code>##

use threads;
use Thread::Queue;

sub fitnessCalculation{ ... }
sub mixAndMutate{ ... }

my $Qwork = new Thread::Queue;
my $Qresults = new Thread::Queue;

my @workers = map 
    threads->create( \&fitnessCalculation, $Qwork, $Qresults 
), 1 .. $noOfCores;

my @data = readData();
my @generation = genRandomGeneration( 1000 );

while( 1 ) {
    $Qwork->enqueue( @generation, (undef) x $noOfCores ); ## Updated.
    @generation = ();

    for ( 1 .. $noOfCores ) {
        push @generation, $_ while $_ = $Qresults->dequeue;
    }

    @generation = ( sort @generation ) [ 0 .. 200 ];

    last if $generation[ 0 ]->score > $targetScore;

    push @generation, mixAndMutate( @generation );
} 

report $generation[ 0 ];