Not the same at all. An individual homozygous at a given loci has no guarantee that its offspring will also be homozygous. It will have one copy from that par

Not the same at all. An individual homozygous at a given loci has no guarantee that its offspring will also be homozygous. It will have one copy from that parent, but the other parent may or may not provide an identical copy. If it's a new trait (say a doomsday gene), then no other copies exist in the breeding population, and all offspring will be heterozygous. If the overall population is static, then average expected fitness is two offspring that make it to breeding. Thus, there will be two copies of the 'doomsday' allele in the population, just as there were in the original homozygous parent. In other words, the total number of alleles remains static over time. In order for an allele to take over a population (become fixed), it must confer a fitness advantage, or else make it there by pure chance. Relying on chance, you have to introduce huge amounts into the population so it becomes the majority, otherwise it will be eliminated. Gene drive is completely different as these constructs can copy themselves to the homologous chromosome in heterozygous individuals. Offspring will be homozygous even when only one parent contributes the allele, and thus the expected allele content in the population will double each generation. Now only a few individuals need to be introduced into a population for the trait to become reliably fixed. It's exponential, and it's truly terrifying.