Twins - Biologically, Physically, and Psychologically Similar Essay

What would it be like to have a twin? This is a question people often ponder. People often say that they see someone that resembles someone they already know. It is almost like dejavu. â€Å"Twin† comes from the German word â€Å"twine† meaning â€Å"two together† (Nagy 1). Most people automatically think of two people who look just alike when they hear the word â€Å"twin†. However, there is a lot more to twins than just looking alike. Twins are the most common type of multiple births. Many think there are only two types of twins, identical and fraternal; they often leave out conjoined twins. Twins are very unique and fascinating individuals because of their similarities biologically, physically, and psychologically.   Ã‚  Ã‚  Ã‚  Ã‚   An author from the twin’s network stated that, â€Å"A British scientist was the first to say that identical twins are identical biologically and may have come from a single egg† (Nagy 1). He was correct when he made this hypothesis. Identical twins form when a single fertilized egg splits usually one to fourteen days after conception (Wade 53). Identical twins are the same sex, they have the same chromosomes, and are the same blood type. Identical twins also mean monozygotic twins. According to the twin’s network, studies show that identical twins live longer than fraternal twins; they believe this is due to their close communication (Nagy 1). Fraternal twins are the most common type of twins. They are the result of the union of two eggs and two sperm. Fraternal twins can be the same or different sexes (Wade 53). Segal says that, â€Å"They are two individuals, no more genetically alike than brothers and sisters that develop from separate fertilizations† (Segal 1). Amazingly, fraternal twins can be conceived at separate times and have different fathers. It seems to be a hereditable trait to conceive fraternal twins. Yet, tendency to conceive conjoined twins may be caused by genetic and environmental conditions (Hunter 1). Conjoined twins are the rarest type of twins. Conjoined twins were once known as â€Å"Siamese twins.† Conjoined twins originate from a single fertilized egg so they are always identical and same sex twins. The developing embryo starts to split into identical twins within the first two weeks after conception but stops before completion. A partially separated egg is left of the embryo, and it continues to mature into a conjoined fetus (Hunter 1... ...rities and the same preferences. They also felt an immediate bond upon meeting. Jim Springer and Jim Lewis are twins who were separated four weeks after they were born in 1939, and they were reunited thirty-nine years later. The twins discovered that they had married and divorced women named Linda, married second wives named Betty, and named their first sons James Allan and James Alan, respectively. They both drove the same model of blue Chevrolet, and they both enjoyed the same hobby. They often vacationed on the same small beach in St. Petersburg, Florida, and owned dogs named Toy (Heredity 62). There have been many cases reported similar to this one, such as where twins were separated at birth and when reunited, found that they had astounding similarities between the two. By studying twins who were reared apart, scientists are learning how the forces of nature and nurture interact to make us what we are (Chensanow 69). Many environmental, genetic, and emotional factors are related to the composition of twins. Any types of twin share a relationship that most people will never experience. Twins, whether fraternal, identical, or conjoined, are an amazing phenomena of human life.