Tsaba said:
Why? Genes have nothing to do that makes that person, they could have the worst genes in the world, but, have the best personality.
I ... I ...
Is science education this bad? I honestly intend no offence, for it isn't your fault you've been miseducated and education is
in no way related to intelligence (i.e. I'm not calling you stupid).
Here's a (very) brief run down on genes for people who haven't had the best science teacher:
TL;DR: You missed a free science class here! Genes make everything in you and everything in you includes your brain and thus your thoughts etc.
[HEADING=3]How genes work[/HEADING]
Genes are sequences of chemicals called nucleotides that combine in a specific relationship to create an order of nitrogenous substances called 'bases'. There are four bases in DNA and each directly corresponds to another, which allows genes to be copied through templates. These little strands of template genes (called Messenger Ribonucleic Acid, or mRNA) bind to an organelle (specialised little part of your cells) called a ribosome where Transfer RNA (tRNA) molecules bring the building blocks of proteins (amino acids) to the mRNA.
These tRNA molecules are each bound to specific amino acids and each have bases that correspond to those 4 bases on the mRNA molecule we mentioned earlier. As we said earlier, these bases correspond to one another in 'base pairs' which means they can
only match up in a single specific way. This means that these tRNA molecules bring their specific amino acid to the mRNA to create a specific chain of amino acids that all bond together in a line of peptide bonds into a protein.
Now, because these amino acids are pretty vibrant molecules with very specific structures, they interact with one another within the protein to give each protein a unique and intended shape and therefore make it specialised for a function. Muscle proteins need to be
very strong, so their structure of amino acids is densely packed with three different strands, each of which form many little hydrogen bonds with one another. Enzyme (the little proteinous molecules in your body that control every reaction) proteins need to be a specific shape to catalyse specific reactions.
Because your enzymes control
every reaction at
every stage in your body and because everything in your body, from your toenails to your brain, is created by a reaction (or chain of reactions) your enzymes essentially make you who you are. Your enzymes are in turn made who they are by mRNA which is made what it is by the genes it uses as templates. Because your brain
is you and its specific regions control specific functions (and it's been shown for a long time that irregularities in brain functions, even as diverse as Schizophrenia, are attributable to irregularities in shape), if you've got genes that code for the production of undesirable mRNA which in turn code for the production of undesirable proteins which have the wrong specific shape for their intended function then you're very likely screwed for life with no way of having the issue ever sorted out, relying on palliative (non-curative) care forever, like neuroleptic drugs.
Genes make or break you. Literally.
TL;DR: Seriously? You're seriously going to tl;dr a topic about sex? Fine. Genes are mixed around in your sex cells (e.g. sperm) and then combined with completely fresh takes on the same gene (called alleles) in your mate's sex cells during sex.
[HEADING=3]How sex works[/HEADING]
In a normal human non-sex cell there's 46 chromosomes. Chromosomes are coiled up strings of DNA. Deoxyribonucleic Acid, more commonly known as DNA, is basically a long strand of genes. It's like an unimaginably long line of bases, facing their opposite pairs. Two of those chromosomes are sex chromosomes, controlling the gender of the child. The others all control the myriad functions that make us people.
As I previously mentioned, there are two sex chromosomes. There's actually two copies of every chromosome, we only really have 23 'unique' chromosomes coding for specific functions, but we have two sets of each chromosome with one being from each parent (called 'homologous pairs'). This allows for alleles of genes. An allele is a variation on a given gene, a change in its bases which results in a different end protein. The reason some people have green eyes and others blue is because there are different versions (alleles) of the gene for iris fibrovascular pigment. Some alleles will always be expressed (used as a template for mRNA) if present and we call these dominant, some will only be expressed if they're the only ones from which the mRNA can be copied (i.e. if neither parent gives the dominant gene) and we call these recessive. To show how this dominance/recessiveness stuff works we can examine the sex chromosomes, Y and X.
Human females are always XX without exception and human males XY. So what decides if you have a boy or a girl? Sperm! When a sperm is created it goes through a process called 'random assortment' where its full 46 chromosomes are halved and each one of the homologous pair (the two different copies of each of the chromosomes we get from our parents) is 'randomly' (it's not really random, but it gets very complex) assigned to the sperm to make only 23 chromosomes. Since there's both an X and Y chromosome present in the male, but only X and X present in the female, the male's sex cells always 'choose' the gender of the child. If the sperm was given a Y then it combines with the mother's X to produce a boy, if it was given an X then it combines with the mother's X to produce a girl.
Where eugenics, and this debate, gets concerned is this recessive/dominant stuff. Let's take a very simplified and unrealistic example (so I don't have to think too hard!) and claim Schizophrenia is caused by just a single gene. One of the theories of Schizophrenia is that the lateral ventricles (fluid filled cavities in the brain that keep everything in place and act like shock absorbing coolant packs) become massively enlarged so that the actual volume of 'brain tissue' massively decreases. This has been successfully shown on x-ray and autopsy, but it's not been accepted as fully working theory yet. But let's keep this simple and say that enlarged lateral ventricles
are the cause of schizophrenia and they're coded for by just one gene: Hypothetical 1.
Hyp1 comes in two forms, HYP - a dominant gene that makes normally functioning lateral ventricles and hyP - a recessive gene that makes enlarged ventricles. If Adam meets a lovely lady, Eve, and both have received only HYP genes from both of their parents then everything is balmy because their child will necessarily be HYP, HYP. If only Adam
or Eve has received a bum hyP gene from a parent (to have hyP, HYP) then everything's still cool because the worst that could happen would be that the child could become hyP, HYP and the good HYP gene would always be expressed because it's dominant. But if both Adam
and Eve had received hyP, HYP then things aren't looking so great for their kid. Neither Adam nor Eve would have schizophrenia because both of them have a dominant HYP allele blocking out that recessive troublesome hyP. However, their child could end up HYP, HYP or HYP, hyP or the dreaded hyP, hyP. If it ends up hyP, hyP then its mRNA would have no choice but to express the defective gene and leave their kid with schizophrenia.
[HEADING=3]Conclusion[/HEADING]
This is why eugenics isn't something to be feared, it's something to be admired. We can completely obviate genetic disease through careful selection of partners. Love a person, but the genes are incompatible? No worries, use donor sperm or have your sperm genetically modified (first you'll need to stop the religious from blocking all our attempts to study this route)!
I hope I've been helpful and haven't offended anyone because that's not what I set out to do. It also took an hour to write.
