Let's assume a laboratory setting and take sex out of the equation, so we avoid the whole sperm finding the egg problem and the sperm not having the correct equipment to borrow into the egg. In this setting you are able to sequence the genome and understand what most parts of the DNA do for both species. Now it's time for another Bio-lesson folks: GENETICS!
DNA is the code for all life. What does that mean? You have 4 nucleotides that make up this code, Adenine, Thymine, Cytosine, and Guanine. A bonds with T and C bonds with G. These bonds make up the rungs in the ladder that is DNA. In order to make a protein, the DNA is unraveled by proteins, and transcribed into RNA which replaces Thymine with Uracil. Very important: Only one side of the DNA is used for transcription. The other side serves other purposes like proof-reading the primary strand and making sure bad things don’t bid to it and screw up the code. This RNA is then read by a unit called a Ribosome. It reads the RNA like a ticker tape and ‘finds’ and binds the correct amino acids together in the sequence that the RNA presents.
Amino acids are the building blocks of proteins. Think of amino acids as words. They are strung together to make sentences, a poly-peptide chain. This chain folds on itself, making a protein sub unit. Think of this as a paragraph. These paragraphs join together to make a paper, a full protein.
Now, back to the lab. We have this problem of chirality, the direction that the DNA spins in. As I stated before, Quarians are dextro based, meaning theirs spins right handedly. Humans are levo based, spinning left handedly. So, let’s work our fancy super science and spin the DNA the other direction. This will take an amazing leap of genetics the likes of which I can’t even comprehend, but for the sake of hypothetical, we will. So now we’ve spun the human DNA backwards so that it will mesh with Quarian DNA. The next problem is chromosome count.
Each species has a specific number of chromosomes. Humans have 22 pairs of autosomal (non sex) chromosomes and one pair of sex chromosomes (X and either X or Y). I have no idea how many pairs of chromosomes a quarian has. A chimpanzee, our closest relative on earth has 24 pairs. When cells divide to become gametes (sex cells), the chromosomes are de-paired and mixed around so each cell only has half the number of chromosomes. That way, when the gamete recombines with another sex cell, they will have 23 pairs again. Without equal pairs of chromosomes, the possible fetus won’t form correctly. And even if it does, it would most likely be sterile.
Lets make another leap in genetic science and say that we are able to dice up chromosomes, replace them with others and more or less equalize the chromosome count. You’ll be changing the species by doing that, so that it really isn’t either human or quarian, but let us say that it is possible. Now we have to return to a previous issue. When we reversed the chirality of the human DNA, we also reversed the side that is read by the proteins. The problem is, this other side contains no useful information. Yes, it will make proteins, but these proteins won’t do anything. Their form wouldn’t be recognized by either quarian or human. In order to make genetic sense, you’d have to completely rewrite the base pair sequence. And at that point, you would cease to have any information that would be Sheppard related. You are rebuilding the genetic ladder. It may still be made out of the particles that make up Sheppard, but the identity of Sheppard comes from the order of the base pairs, not the base pairs themselves.
Sadly, this means no Tali/Sheppard hybrid. You’d be creating another sentient being that is neither human, nor quarian but something else and it would not have any of the traits of one of the donor species.
This one was done solely by memory. If there’s anything wrong, please tell me, this will be my profession and I can’t really afford to be wrong.
TLDR: We have two different puzzles and though we can mix the puzzles up and carve the pieces with an exacto-knife, the picture that comes out will be meaningless an incomprehensible.
Modifié par Uberpenguin7, 25 février 2010 - 06:21 .