Essay on Human Twins is published for informational purposes only. The free papers are not written by our writers, they are contributed by users, so we are not responsible for the content of this free sample paper. If you want to buy a quality Essay on Essay on Human Twins at affordable prices please use our essay writing services offered by EssayEmpire.

Human twins have always been objects of especial interest, partly perhaps on account of the fine humor of the situation, and partly because of the frequent occurrence of "look-alike" twins or "duplicate" twins. Popular interest has quite naturally focused upon the striking similarity, amounting in some cases to almost complete identity, which exists in certain types of twins; this emphasis upon resemblance is justified by the biological analysis of twinning, as is shown in what follows.

Biologists have for some time recognized at least two distinct types of human twins: fraternal and duplicate. Fraternal twins may or may not be same-sexed, are usually no more alike than are brothers and sisters, and are believed to be dizygotic, derived from two fertilized eggs. Duplicate or identical twins are always of the same sex, are almost identical, and are believed to be monozygotic, derived from a single fertilized egg.

No twins occur in nature at all comparable with the old favorite type which has done such signal service in the drama and in fiction (not to mention the "movies"), wherein brother and sister are identical. Science, however, can afford to be magnanimous, so let us as a concession to art include in our list these "literary twins."

Another type of human twins, stranger than fiction, is found in conjoined twins and double monsters, of which the Siamese twins furnish a stock example. There appears to be a graded series of types ranging between duplicate twins and the less monstrous types of conjoined twins; similarly, the conjoined twins appear to grade into the various kinds of double monsters. Some conjoined twins are very lightly connected and some double monsters are so closely united that one individual may be a mere degenerate parasite upon the other. The fact that very lightly conjoined twins exist would point to the probability that such twins might sometimes be born separately. This is Wilder's view of the relation between duplicate twins and double monsters. Lightly conjoined twins are always of the same sex and are strikingly similar; there seems to be no question as to their monozygotic origin. What more natural, therefore, than to infer that separate twins which are of the same sex and strikingly alike are also monozygotic? . . .

Free essays are not written to satisfy your specific instructions. You can order a term paper, research paper or custom TOPIC at our site which offers professional essay writing services. Get your high quality custom paper at relatively cheap prices. EssayEmpire is the best solution for those who seek help in essay writing related to TOPIC and other relevant topics.