All of us have unique DNA, one part of it is from our father the other part is from our mother. Suppose there is a way to allow human being to give birth to a pair of twin whereby the male inherited 100% of the gene from father and the female inherited 100% of gene from mother, my question is how will present society benefit from this trend despite the fact that we will also inherit the flaw such as genetic short comings? most importantly will it kills family value? Actually this is part of my villian's plot to rule over the world I'm hoping the plan works I could care less about the ramification or should I?
2$\begingroup$ Your villain's plan for world domination seems to me like the plan for profit of the underpants gnomes in South Park. $\endgroup$– PhilippJul 15, 2015 at 14:27
5$\begingroup$ I have an identical twin and thus don't have unique DNA. You don't need to pretend like we don't exist. $\endgroup$– SamuelJul 15, 2015 at 16:15
If all children came in pairs one exact duplicate of each parent, it would immediately stop (well almost) the evolution of the human species. Evolution comes about by the mixing of genes and 'better' changes becoming dominant. What you are asking about is effectively asexual reproduction. Any change to the children would be accidentally imperfect gene reproduction.
The benefit, would be you would know a lot about your child's future health, and maybe be able to prevent or reduce any negative impacts, you can also expect them to have similar behavior to your self. There would never be any question on whose child it is either, paternity tests would be moot.
It might actually make family ties stronger since there would be no question if either partner strayed and had children by someone else, and any children you had would really be 'you'. Though at that point family ties themselves would likely be looser outside of the parental relationship, because, both of your kids wouldn't have any genetic reason not to have an intimate relationship, and as a matter of fact might find each other attractive for the same reasons their genetic duplicates (parents) did. Even worse, when the children get older they will look exactly like their parents did at a younger age (I'll stop there).
But one thing it might do is encourage families to split, mom takes daughter or daughters and dad takes son or sons. It could encourage a strange breakdown between the sexes. Since each family the siblings would be more like step siblings and not biological siblings.
1$\begingroup$ I think that the evolution of the human species is already comming to a halt, because in developed countries there is almost no natural selection anymore. $\endgroup$– PhilippJul 15, 2015 at 14:20
1$\begingroup$ @Philipp How do you reckon that? Is your breeding selection entirely random? $\endgroup$– SamuelJul 15, 2015 at 16:27
1$\begingroup$ @Philipp Number of Children still impacts it. Also look up the Darwin awards. $\endgroup$– PyRulezJul 20, 2015 at 22:48
1$\begingroup$ @PyRulez curiously, in many developed countries those demographics with a lower income and level of education - indicators for less desirable genetic traits in our society - usually have more children. And people who manage to kill themselves through their own stupidity are so few that it is not statistically significant. Look up the statistics. In developed countries, almost every child which is born will survive into adulthood and have 1.5 - 2.5 children before they die. $\endgroup$– PhilippJul 21, 2015 at 7:39
$\begingroup$ @Philipp The Darwin award was a joke. And that's the ironic, what we usually see as success, industrial society and such, is biologically unsuccessful. $\endgroup$– PyRulezJul 21, 2015 at 12:46
Well you could flat out clone 2 people and implant the embryos in 1 woman to carry to term though they wouldn't really be twins in any meaningful sense of the word apart from sharing a womb, they wouldn't be related unless you were cloning related people.
It has been quite possible to produce clones with present technology for decades though human cloning is considered unethical since clones have a higher rate of deformities and defects than regularly-conceived children.
But what's the advantage for your villain? A clone isn't you, it's just a kid very similar to someone else, a twin born decades after yourself with a few extra mutations.
There aren't really any benefits to doing this, in fact it's far less efficient than either standard sexual or asexual reproduction.
The main advantage of asexual/cloning reproduction is that you only need one person involved.
The main advantage of sexual reproduction is the ability to mix genes, this allows positive traits to spread and makes it harder for diseases and parasites to spread through the population.
The scenario you propose loses both of those benefits and does not gain any to compensate.
From a social perspective you have no real extended family. If you are female then your mother, grandmother, sisters, daughters are all identical to you genetically speaking. However your father, brother, uncle, grandfather are no more related than any stranger.
Custody and support battles might become interesting (the father might say "I'll pay support for my son but not for my daughter"), and it's quite likely that couples would keep having children until they had at least one of each gender and would then favour the children of their own gender.
One big thing to keep in mind though is that genetics is only one factor. There are all sorts of environmental things in not just your life but your parents and grandparents that change how you develop. For example see this article: http://www.livestrong.com/article/542877-the-average-height-of-humans-over-time/
The changes in height described there are not due to evolution or genetic changes, but due to environment.