The power of DNA profiling (editted)

Before proceeding to question 6, lets run through some facts about TWINS, since its relevant to our currrent stage in the mystery.

According to medical dictionary, monozygotic twins or identical twins are two individuals developed from one fertilized oocyte; hence, they have identical genomes.

How does this happen?

Comparison of zygote development in monozygotic and dizygotic twins

Identical twins are formed after a blastocyst essentially collapses, splitting the progenitor cells (those that contain the body's fundamental genetic material) in half, leaving the same genetic material divided in two on opposite sides of the embryo. Eventually, two separate fetuses develop.

Fun fact (well..kind of)

Spontaneous division of the zygote into two embryos is not considered to be a hereditary trait, but rather a spontaneous or random event. Monozygotic twins may also be created artificially by embryo splitting.

       

                         Embyo splitting 1                                          Embryo splitting 2

Genetic similarity: 

1. Identical twins do not have the same fingerprints, due to the fact that even in a small space inside the womb, people have contact with different parts of this environment, which gives small variations in the same digital, making them unique
2. Monozygotic twins are genetically nearly identical and they are always the same sex unless there has been a mutation during development. 

DNA patterns from four sets of twins 

Our DNA also changes in response to things like sunlight or the food we eat. Both can damage the DNA causing mistakes to happen. All of the changes aren't in all of our cells -- not all of our cells have the same DNA sequence! If a DNA mistake happens late in our development, then only a few cells will have that mutation. If a mistake happens early, then more cells will have the DNA change but still not all of them. Such mutations, however, are normally so tiny that DNA analysis can't detect them.

With the technology that we have currently, the police are unable to determine which twin was involved with  the crime. So what do the police do?

Well, police don't use DNA analysis since the DNA is the identical, hence police dust for fingerprints.

Comparison of palatal rugae patterns in siblings and twins

Comparison of palatal rugae patterns in siblings, twins and parents revealed no similarity of rugae patterns. This suggests that there is no evidence of rugae pattern features inheritance. Similar results were given by Fahmi et al (2001) who reported that no two palates are alike in their configuration. Even between twins, the patterns are not identical.

Science of lip prints is called cheiloscopy.

Japanese doctor Suzuki is supposed to have done the greatest work on lip prints. In 1970, he recalled the attention of everyone on the fact that the possible use of lip prints in personal identification. He examined 18 pairs of uni-ovular twins aka identical twins and found that there were considerable similarities in these twins. Before proceeding further, it would be proper to explain briefly about uni-ovular twins. These twins were initially conceived as a single individual from a single ovum, they are called uni-ovular twins. They are always of the same and are very much similar in appearance. It is in the light of these facts that Professor Suzuki was studying lip prints. But of the 18 pairs of uni-ovular twins that he studied, he found remarkable similarities. This was somewhat depressing for the forensic scientists although quite predictable.

             However MacDonell in 1972 described two identical twins who seemed to be indistinguishable by every other means, but lip prints in these twins differed. This was interesting news as identical twins had not been distinguished before by lip prints. He could differentiate between them by some other methods too. These were fingerprints, handwriting, voice prints and nail clippings.


Moving on to the question, 

The question is as follows:
The DNA profile showed evidence for a father and son. In addition there was DNA profiling pattern that matched one living twin (Tanya Rosilawati). With this, match the evidence to these victims who were earlier filed for missing persons. Explain your rationale.

Picture 1: Adult’s skull & jaw

Picture 2: Pieces of a jaw

Picture 1 and 2 shows two adult remains and along with DNA profiling evidences, we can deduce that they are father and son. Thus, the remains most probably belong to Herman and Adi.


Picture 3: Child’s jaw

Picture 3 will then belong to Anya since the DNA profile matches the living sister, Tanya.
Since both of them are identical twins, meaning they come from the same fertilized egg, which had only one complete set of DNA in the first place. That fertilized egg and its single set of DNA split to form twin embryos-each with its own set of DNA, identical to the other.

So, that marks the end of another week. Only one week to go =D