Basically the first step would be that two eggs get fertilized by different men's sperm. Then these twins would fuse together to create a chimera with two different dads. Since both steps are rare, it will be really rare for both to happen at the same time. But it is definitely possible.
Although this is quite rare it can happen and it's called superfetation. Two babies are conceived from separate acts in two different cycles. These babies can be from the same father or two different men. When heteropaternal superfecundation occurs, the babies are from different fathers.
Chimeras Aren't More Likely to Have Kids with Chimerism
Even when the ovaries or testes of a chimera are made up of cells from both “twins,” their sperm or egg cells will only get DNA from one “twin” or the other. This is due to a process called meiosis.
A chimera is essentially a single organism that's made up of cells from two or more "individuals"—that is, it contains two sets of DNA, with the code to make two separate organisms. These individuals often don't know they are a chimera.
Chimeras can often breed, but the fertility and type of offspring depends on which cell line gave rise to the ovaries or testes; varying degrees of intersex differences may result if one set of cells is genetically female and another genetically male.
Tetragametic chimerism
A hermaphrodite chimera is a variant of a tetragametic chimera where a female embryo is merged with a male embryo, and the resultant chimera will have both male and female specific markers in their body.
Chimerism, the presence in a single person of cells derived from two or more zygotes, is one such rare anomaly. It is usually ascertained through anomalous blood-grouping results or (for XX/XY chimeras) sex reversal or intersex.
Lydia Fairchild (born 1976) is an American woman who exhibits chimerism, having two distinct populations of DNA among the cells of her body.
Sometimes a DNA test can easily show that you are a chimera. A quick cheek swab, a strange result with three or four versions of a specific marker and BAM, you're a chimera. Sometimes you need to test your blood and your skin cells to find out. You get two different results from each and BAM, you're a chimera.
Abstract. Twin blood group chimerism seems to be very rare in humans. The 30-40 previously reported cases usually were found by mere coincidence during routine blood grouping in hospitals or blood banks. Usually in these cases frank blood group mixtures of, for example, 50/50%, 25/75%, or 5/95% at most were seen.
In rare cases, fraternal twins can be born from two different fathers in a phenomenon called heteropaternal superfecundation. Although uncommon, rare cases have been documented where a woman is pregnant by two different men at the same time.
On a relatively basic level, artificial insemination and surrogacy result in an offspring with two genetic parents, but with a third parent as the mother carrying the child. In more extreme cases, it is possible for a child to be created with three genetic parents.
Sometimes children end up looking exactly like one parent, or even closely mirroring a sibling, and sometimes they don't resemble anyone in the family. It's all entirely possible. Kids share 50% of their DNA with each of their parents and siblings, so there's plenty of room for variation.
Recently, researchers with the Institute of Life in Athens, Greece, announced that a healthy baby boy was born who basically had the DNA from three people. The child was born to a 32-year-old woman who had failed in four cycles of in vitro fertilization (IVF).
In this case of semi-identical, or sesquizygotic, twins, the egg is thought to have been fertilised simultaneously by two sperm before it divided. If one egg is fertilised by two sperm, it results in three sets of chromosomes, rather than the standard two - one from the mother and two from the father.
These days, more same-sex male couples are creating their own families through surrogacy. There are two types. Full or gestational surrogacy is when a fertilised donor egg is implanted into a surrogate through in vitro fertilisation (IVF). The surrogate has no genetic connection to the baby.
They resemble long, segmented armored worms, with multiple eyes on their heads and sharp, shearing teeth. Their heads are similar in appearance to those of Hybrids. A fossilized skeleton of a Pure Chimera can also be found in the mines of Mount Pleasant in Resistance 3.
Like sharks, chimaera are vulnerable to commercial fishing pressure. They're long-lived - it's thought they live up to 30 years, likely longer. They also reach sexual maturity late and produce few young.
The most common form is fetal-maternal microchimerism, where the fetus and mother exchange cells (through the placenta), which can remain in circulation in the mother decades later. One study found nearly 50 percent of female chimeras had Y-chromosomes (presumably from their sons) detected in heart biopsy tissue.
In the roleplaying game Dungeons & Dragons, the chimera is an evil-aligned creature which looks like a lion with leathery wings on its back. To either side of its lion's head is the head of a goat and the head of a dragon.
Experts aren't sure how many human chimeras exist in the world. But the condition is believed to be quite rare. It could be becoming more common with certain fertility treatments like in vitro fertilization, but this isn't proven. Only about 100 or so cases of chimerism have been recorded in modern medical literature.
Yes, it is very likely that two human can look very similar, possibly even identical, but they will never be genetically identical. The odds of this happening are so as close to zero as you can get. Yes, it is possible for two humans to be genetically identical, but so slim that our world may never see.
Most chimeras remain undetected, especially if both zygotes are of the same genetic sex. Many are discovered accidently, for example, during a routine blood group test. Even sex-discordant chimeras can have a normal male or female phenotype.
The chimera had a fearsome weapon - she was able to breathe fire. This, combined with her lion's strength, goat's cunning and snake's venom, made her nearly invincible. The chimera lived in Lycia, where she terrorised the people and ravaged the land with her fire breath.
Typically, the Chimera is portrayed with the body and head of a male lion, the head and body of a lion, with the head of a goat arising from its back, and a tail that might end with a snake head. She does not typically have the power of flight, a weakness which is exploited by Bellerophon on his flying steed, Pegasus.