Identical twins have the same genetic material, but as you can see, every egg they both make is different. Every sperm a man makes is different. Hence the chances of their babies being identical are pretty close to zero.
Although rare, a woman can release multiple eggs during a single menstrual cycle. If she only has intercourse with one man, she can become pregnant with fraternal twins with the same father. Genetically, the twins come from different eggs and sperm, but they have the same parents.
What would happen if fraternal twins had a baby together? If they're all fraternal twins the children would be double cousins, but not any more similar than if the parents were regular siblings. If one set is fraternal and one identical the cousins would be genetically a bit closer than half-siblings.
However, since only women ovulate, the connection is only valid on the mother's side of the family. While men can carry the gene and pass it on to their daughters, a family history of twins doesn't make them any more likely to have twins themselves.
That's why, though children. of identical twins are legally cousins, they are. genetically the equivalent of half-siblings.
Like for their twin parents, there are many fascinating family relationships for the children of twins–when identical twins have children, their children are cousins but genetically as similar as half-siblings.
Since identical twins share the same DNA, the children of two pairs of identical twins are legally cousins, but genetically more similar to siblings.
A dad who's one of a twin may inherit the gene, but it won't increase his chances of having twins too, because the gene only affects ovulation. The same dad may pass on the gene to his daughter, who then goes on to get pregnant with twins, making it look like twins have skipped a generation .
The twin gene is carried by the mother, meaning that it is her genes that determine whether someone may have fraternal twins. Hyperovulation can also play a role depending on certain conditions such as obesity and diabetes or age-related hormonal changes in women over 35 years old.
However, few genes appear to be definitively linked to hyperovulation, so it could just be that genetics in general on the mother's side contribute to the probability of having fraternal twins. Heredity on the father's side, on the other hand, does not increase a couple's odds of having twins.
While it's tempting to wonder whether your twins might sleep better together, the only safe snoozing setup is to place each baby in his own crib or bassinet. Sticking with safe sleep guidelines is always crucial, but it's especially important for twins.
Twin sisters who married twins reveal their sons are genetic brothers and cousins. Identical twin sisters who married identical twin brothers have given birth to sons who are brothers and cousins at the same time.
The biological phenomenon of giving birth to twins with two different biological fathers is called heteropaternal superfecundation. In a rare and surprising event, a 19-year-old Brazilian woman gave birth to twins who belong to two different biological fathers.
Yes, it is possible for a baby to have two biological fathers through the phenomenon known as “bipaternalism” or “heteropaternal superfecundation”. This occurs when a woman ovulates twice within the same menstrual cycle and has sexual intercourse with two different men during that time.
Sean Blackburn is a fact-checker and researcher with experience in sociology and field research. For the most part, twins and multiples share the same birthday. However, depending on the time of day the babies are born and how long the timespan is between each baby's birth, twins can be born on different days.
This belief is based on the assumption that twinning is genetic and runs in families. However, if that was truly the case—if there was a twin gene—then twins would occur with predictable frequency in those families that carry the gene. There is no concrete scientific evidence that suggests twins skip a generation.
Factors that increase the chance of twins include: consuming high amounts of dairy foods, being over the age of 30, and conceiving while breastfeeding. Many fertility drugs including Clomid, Gonal-F, and Follistim also increase the odds of a twin pregnancy.
Identical (i.e., monozygotic, or MZ) twins share 100 percent of their genes, whereas fraternal (i.e., dizygotic, or DZ) twins generally share only 50 percent of their genes.
Everyone has the same chance of having identical twins: about 1 in 250. Identical twins do not run in families. But there are some factors that make having non-identical twins more likely: non-identical twins are more common in some ethnic groups, with the highest rate among Nigerians and the lowest among Japanese.
Age – Generally older women have a higher chance of conceiving twins than younger women. A woman at 35 years old is 4 times more likely to have fraternal twins. As women age near menopause, they will experience hormonal changes where their follicle-stimulating hormone rises.
Homopaternal superfecundation is fertilization of two separate ova from the same father, leading to fraternal twins, while heteropaternal superfecundation is a form of atypical twinning where, genetically, the twins are half siblings – sharing the same mother, but with different fathers.
They may share the same mother but different fathers (in which case they are known as uterine siblings or maternal half-siblings), or they may have the same father but different mothers (in which case, they are known as agnate siblings or paternal half-siblings.