don`t be use mallor ,free function,they are from c,if you use they,you memory will be lost.
in lite,you can use sys_malloc,sys_free,like this code.
Code:
typedef struct
{
	char fitness;
	int* dna;
}organism;
void main(){
	organism* Agent = sys_malloc(sizeof(organism));
	Agent.dna 		 = sys_malloc(5*sizeof(int));

	//reset your memory,make all is '\0'
	memset(Agent.dna,'\0',5);
	
	//and than set your varible
	(Agent.dna)[3] = 12; 
	printf("%d",	(Agent.dna)[3]);
		
	sys_free(Agent.dna);
	sys_free(Agent);
}

development 3d game is interesting!