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Researched by Jamielyn R. |
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General Introduction
Multiple birth is what you call twins, triplets,
quadruplets, and even larger groups of babies born at the same time.
Multiple birth babies can be identical or fraternal, or for triplets
and above, a mixture of the two. Identical multiples look exactly the
same; fraternal twins look either similar or totally different.
Twins (In General)
In 1997 alone 104,137 sets of twins were born in the
United States, an average of 143 sets per day. Women have a one in 35
chance of having multiples, one in 37 chance of having twins. Twins are
the most studied kind of multiples in the United States. Twins are the
most likely multiple you could have. Twins occur about once in every 87
births. The most common type of twins is fraternal.
Twins in Greek Mythology
In Greek mythology, the most famous pair of twins was
Castor and Pollux. They were the sons of Zeus, the king of all
gods. Castor and Pollux protected sailors. When Pollux died, Castor
begged to join him in heaven, and he did.
Twins in Roman Mythology
In Roman mythology, the most famous pair of twins was Romulus and
Remus. They were the sons of the god of war, Mars. They were abandoned
at the Tiber River as infants. They were found by a mother wolf and
nursed back to health, until a shepard came and claimed them as his
own. He raised them until they were old enough to be on their own.
Romulus and Remus stuck together until they founded the city of Rome.
They later fought for control of the city, which ended in Remus’s
death. Some Romans say Romulus and Remus never existed, but some think
otherwise.
Premature Twins
Premature babies are born in fewer than 37 weeks, with the
normal being 40 weeks. Half of all twins in the world are premature.
Fraternal Twins (Dizygotic Twins)
Two-thirds of all twins in the world are fraternal.
One-half of those are born boy and girl. Some fraternal twins look
similar, but some look totally different. Fraternal births are highly
variable and occur frequently among black Africans, but they are least
common among Asians. Pregnancies involving fraternal twins happen when
the mother’s ovaries release two eggs at about the same time, the eggs
are fertilized separately by two different sperm. The babies grow from
two different fertilized eggs. They have different genetic makeup and
characteristics. They look no more alike than a brother and sister who
are not twins. The following triplets are obviously not identical
in appearance or in gender!
Identical Twins (Monozygotic
Twins)
Identical twins are always of the same sex and have the
same genetic makeup. Pregnancies involving identical twins start with a
single fertilized egg.. Identical twins occur early in the mother’s
pregnancy. This happens when the egg’s cell mass splits into two parts
and develops two separate individuals. Identical twins have the same
genes and similar personalities. Identical twins reared apart are about
the same as identical twins reared together. It has been suggested that
identical twins can communicate telepathically. Scientists found that
similarities between identical twins have nothing to do with telepathic
communicating. They are due to the fact that they have similar thought
waves.
Siamese Twins (Conjoined Twins)
About one in every half-million births are conjoined
twins. There are fewer than 50 pairs born a year. They are always the
same sex and same blood type. Conjoined twin pregnancies happen exactly
the same as identical pregnancies except the egg doesn’t split all the
way. The majority of conjoined twins are female. The first successful
separation of conjoined twins was in 1689. The most common type of
conjoined twins is connected at the chest and abdomen. The most unusual
type of conjoined twins are dicephalic twins, which are joined at the
head with a two-legged body. Often, only one twin survives surgery, in
the worst cases both twins die. In approximately 300 years of medical
history, only 100 pairs of conjoined twins were separated successfully.
One of the first conjoined twins to survive to adulthood were Eng and
Chang (below).
Eng and Chang Bunker
Eng and Chang Bunker were born in Mekong, Siam (now
Thailand) in 1811. Although they were conjoined, they still learned to
walk, run, swim, and handle a fishing boat. Their father died in 1819
when Eng and Chang were just eight years old. Eng and Chang went to
work for local fishermen for money. They saved up that money and
started their own business. When a trader named Abel Coffin wanted to
take the boys to America he gave their family $500.00 (which was a lot
in that time). Eng and Chang became known as Siamese twins. Coffin
charged 50 cents for people to see the boys. When Coffin took the boys
on a British tour they took a boat. While Coffin had first class the
boys had to stay in the steerage class. Coffin had said that it was the
captain’s fault, but it was not true. Also, Coffin only gave Eng and
Chang a fraction of the money they earned. Eng and Chang quit Coffin
when they turned 21, and bought a little farm in North Carolina to
become farmers. Later the boys’ married two sisters from a Southern
family named Adelaide and Sallie Yates. They got married in 1840.
Between the twins, they fathered 21 children, but none of them were
twins. Later on the families eventually moved into two different homes
with the boys staying three days at each household. They went on a U.S.
tour to make money. Eng and Chang died on January 17, 1874 at the age
of 63. Chang had died in his sleep from a blood clot in his brain, and
Eng died within an hour from shock.
Birth Defects
Twins are 50% more at risk for birth defects, but boys are
more at risk than girl twins. They can develop problems such as brain,
heart, bladder, and heart problems. Boys have a 29% higher risk of
birth defects such as these. Over the past 20 years twins have been
increasing along with all the birth defects.
Twin Survivors
One twin survivor from a bad time was Eva Mozes, she was
born in Auschwitz, a Nazi concentration camp. Ten years after she was
born Dr. Joseph Mengle (Angel of Death) injected Eva with a deadly
virus and she became deathly ill. After that she was ordered to the
Sham “hospital.” She was denied food, water, and medications. Dr.
Mengle looked at her and said, “Too bad, she only has two weeks to
live.” Eva fought with all her strength to get over the illness, but it
was very hard for her because she kept on fading in and out of
consciousness. One day she found a drinking fountain, and a woman (who
clearly didn’t work at the hospital) gave her some bread. As Eva fought
against her sickness, her fever suddenly broke. As soon as she felt
better she was ordered back to the twins barrack.
Nature –vs.- Nurture
Human beings are a combination of their genetics and the
environment that they live in. For example, the same person will have
different skin color depending on whether they’ve spent the last year
in Hawaii or Northern Alaska. A child could be raised in Japan or in
Mexico or in England. The child’s language, religion, culture,
clothing, and view of the world would be very different depending on
where they grow up. A child raised in a very rich family would be
different than if that same child was raised in a very poor family. A
child that swims regularly would have different muscle shapes than a
child who lifts weights for a hobby. All of these characteristics
influenced by the environment are referred to as “Nurture”.
A person’s genetic makeup determines most of the basic things like
whether you are a boy or girl, your height, your eye color, skin color,
whether your teeth will be crooked or straight, and much more. The
genetics are referred to as “Nature”.
Most aspects however are controlled by both nature and nurture. An
example is your strength. You’re basic body shape and size is
controlled by nature, but your activities and diet are nurture, which
has a lot to do with it too, almost as much as your genetic makeup.
What does this have to do with twins? Scientists use twins to research
the effects of nature –vs.- nurture on human characteristics. For
example, identical twins have the exact same genetic makeup. If they
are raised apart they have very different environments. Any differences
should be due to the environment, or nurture. Any similarities should
be due to nature (genetics). Fraternal twins have different genetic
makeup. If they are raised together any similarities should be due to
the environment (nurture).
Twins are the only people on earth who have identical makeup so the
answer to the nature –vs- nurture question relies on studying them.
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