Twins: Same DNA? Maternal Connection?

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In summary: The movie follows a woman who is told by a medium that she has the same soul as her twin who died in a car accident.
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aychamo
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Do twins, that split from the same egg (is this maternal?) have the exact same DNA?
 
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So called "identical twins," which are formed by an ovum that split into two, generally have the exact same genome. There are a few instances, however, when the genetic material can be modified after the split.

So called "fraternal twins," which are formed by two entirely different ova that just happen to have been released in the same menstrual cycle, have different genomes.

- Warren
 
  • #3
Yes as Chroot said, monozygotic twins have the exact same DNA, although a few instances are known where the karyotype for instance was altered in one of the twins, giving rise to a boy-girl identical twin. Dizygotic twins per definition are independently fertilized zygotes.
 
  • #4
Monozygotic and dizygotic twins

  • Galton's Anecdotal Report on Twins. The use of twins to study the inheritance of behavioral traits was another of Galton's important "firsts." He noted that there were two types of twins, judging from their degree of resemblance. "Identical" twins come from one egg (hence they are now called monozygotic, or MZ, twins), which divides in two shortly after fertilization. Their genetic makeup is identical; thus their genetic correlation is unity (r = 1). And they are very alike in appearance. "Fraternal" twins (now called dizygotic, or DZ) come from two different fertilized eggs and have the same genetic relationship as ordinary siblings, with a genetic correlation of about one-half (on average). That is, DZ twins are, on average, about one-half as similar, genetically, as MZ twins. DZ twins are no more alike in appearance than ordinary siblings when they are compared at the same age.

    Galton was interested in twins' similarities and differences, especially in MZ twins, as any difference would reflect only the influence of environment or nongenetic factors. He located some eighty pairs of twins whose close physical resemblance suggested they were MZ, and he collected anecdotal data on their behavioral characteristics from their relatives and friends and from the twins themselves. He concluded that since the twins were so strikingly similar in their traits, compared to ordinary siblings, heredity was the predominant cause of differences in individuals' psychological characteristics. Because Galton obtained no actual measurements, systematic observations, or quantitative data, his conclusions are of course liable to the well-known shortcomings of all anecdotal reports. Later research, however, based on the more precise methods of modern psychometrics and biometrical genetics, has largely substantiated Galton's surmise about the relative importance of heredity and environment for individual differences in general mental ability.
Arthur R. Jensen. The g Factor. pp12-13.
 
  • #5
Identical twins with mystical psychic connections

http://www.godsendthemovie.com/ new movie is written around the premise that having the identical DNA as someone who had already lived would somehow not be simply the same as being an identical twin.
 
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1. What does it mean for twins to have the same DNA?

Twins are considered to have the same DNA when they are conceived from a single fertilized egg, also known as identical twins. This means that they share 100% of their genetic material, making them genetically identical.

2. Can fraternal twins have the same DNA?

No, fraternal twins are conceived from two separate eggs fertilized by two different sperm. This means that they share approximately 50% of their genetic material, just like any other siblings.

3. How can twins have different physical traits if they have the same DNA?

While identical twins have the same DNA, they can still have different physical traits due to epigenetics. Epigenetics is the study of how environmental factors can influence gene expression, meaning that even though twins have the same DNA, their physical traits can be influenced by their unique experiences and environments.

4. Is there any difference between the DNA of identical twins?

Technically, no. Identical twins have the exact same DNA sequence. However, as they go through life, small mutations may occur in their DNA, which can lead to slight differences in their genetic makeup. These mutations are not significant enough to change their physical appearance or health.

5. Do twins have a stronger maternal connection than other siblings?

There is no scientific evidence to suggest that twins have a stronger maternal connection than other siblings. While they may have a unique bond due to sharing a womb and being born at the same time, the strength of their connection is dependent on individual experiences and relationships with their mother, just like any other sibling.

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