In nature, clones are derived from a single parental organism or cell by mitotic cell division, asexual reproduction, or parthenogenesis. 在自然条件下来源于有丝分裂所产生的单个亲本细胞或生物体，还可能来源于无性繁殖或单性生殖。
Two diploid gametes may fuse to give a tetraploid zygote, or gamete may develop directly by parthenogenesis. 两个二倍体配子融合可能产生一个四倍体合子，这样的配子也可以通过孤雌生殖直接发育而来。
However, reproduction is often by parthenogenesis since polyploid animals are often sterile. 然而，它们常常是通过孤雌生殖繁殖的，因为多倍体动物往往不育。
