And we can look in particular at three types of siblings: identical twins, twins that actually share 100 percent of their genetic information and shared the same intrauterine environment, versus fraternal twins, twins that actually share 50 percent of their genetic information, versus regular siblings, brother-sister, sister-sister, also sharing 50 percent of their genetic information, yet not sharing the same intrauterine environment.
Kita boleh lihat secara lebih dekat tiga jenis adik-beradik: kembar seiras, kembar yang berkongsi 100 peratus maklumat genetik dan berkongsi persekitaran intrauterin yang sama, dengan kembar tak seiras, kembar yang berkongsi 50 peratus maklumat genetik berbanding adik-beradik biasa, abang-adik, kakak-adik, yang juga berkongsi 50 peratus maklumat genetik namun tak berkongsi persekitaran intrauterin yang sama.