Showing posts with label darwin. Show all posts
Showing posts with label darwin. Show all posts

Bad Science behind introduction of genetically modified Zika mosquitos to control their population

Zika is spreading a little bit outside Brazil and Colombia, and a company called Oxitec is proposing a solution. In all likelihood they are twisting their data to fit their needs-to make it look like the mosquitoes they introduce really cause a decrease in the overall mosquito population.

News stories Here and Here for a sum-up of what they are proposing.

"Trials of the modified mosquitoes in Brazil, Panama and the Cayman Islands suggest they reduced local populations of Aedes aegypti mosquitoes by more than 90 per cent," Oxitec says.

Here's the problem from an evolutionary point of view-just because you have created this male Aedes aegypti mosquito which transmits the gene so that  the offspring are killed before they reach adulthood doesn't mean that the females will mate with them. Even if the sexual selection be random, you will just eliminate the offspring of these males; but the other males, who are a large part of the population, will continue producing offspring. This is the best case scenario.

Sexual selection is not random-it is not like that females will mate with any mosquito-and if the mosquito population realize that the offspring of these genetically modified males are not reaching adulthood, they will probably weed them out by sexual selection even faster. Sexual selection by females will accelerate de demise of these traits.

From what Darwin explained in his Domestication of plants and animals and a little bit in the Origin of Species, it is clear that introducing new strains in a plant or animal is the easy part, the hard part is to make sure that their offspring survive the selection pressures of the others who are the more "stable" varieties. In his words, hybrids are easy to create-but will tend to revert to the stable varieties after a few generation, even if they can reproduce. Hybrids most likely will not even reproduce-and the reason was unclear to him-but the evidence is very strong that hybrids are difficult to breed, and even if they do breed, even more difficult is to ensure that their offspring survive and don't revert back to the parent varieties used to create the hybrid.

This thing about Zika males is very similar-and my bet is that introduction of these males has no effect whatsoever on the mosquito population of Zika.

Regarding the data from Brazil, Panama and Cayman Island-I  think the data has been fudged to give them what they want to prove. And doing it in a lab setting may have nothing to do with how this turns out in real life-with loads of other selection pressures on the mosquitoes, both from within and outside their species. This is similar to the myth of antibiotic resistance in many ways.

-Sanjay


Understanding evolution-zebra article today

Some biologists published a study on why they think zebra stripes are not for camouflage, etc. They do not seem to understand evolution quite right.

The winner in evolution transmits all their characteristics to the offspring. But  you can't say that the characteristic (e.g. stripes) was the cause of the individual being a winner.

A particular human being might be a survivor in a difficult situation because of their excellent intelligence. They may have a mole on their right chin, or have a hairy back, etc. All these characteristics will be passed on to their progeny; but it is not because of their hairy back or the mole on their right chin that they are a winner.


Or instead of intelligence, it might be just luck; maybe the individual just hid in a cave while the rest of the pack was eaten by a predator. Since this individual now reproduces, all his characteristics will be transmitted to his offspring.
This can be extended to all animals, I chose human being as an example animal, that's all.

The characteristics you see in a species like a zebra are just that; they are not there because somehow that characteristic lead the species to win out.

Even for sexual selection this is the same. The characteristic is not a cause of victory; it is a by product of already being victorious.

The same intelligent human being might be able to get more mates; but the females are not selecting the individual for their mole on the right chin or his hairy back.

Another scientific study claims that some people in a Bajau, Indonesia evolved into having bigger spleens because they dove in water for longer periods. A whole chain of scientific arguments are published to prove this-apparently the bigger spleen holds breath longer etc. etc.. who knows what the real cause of their better survival is? Maybe the ancestor of this tribe survived because he could survive the sun well, and he also happened to have a big spleen, and thenn passed on his bigger spleen to all the progeny, which resulted in all these individuals today having bigger spleens. The common ancestor may have also had a firmer set of hands, so he could hold on to the fish longer, and maybe that was the cause for the survival of the tribe, not the spleen. A dozen other theories can be made up to prove whatever you want to prove and invoke evolution.

At a very fundamental mathematical level, these studies are committing the classic error of "correlation is not causality".

This is a common problem I see in evolution related publications; essentially they do not get the causality right. The causes of why an individual survives are not known; the characteristics you see in an individual are the effects of them being winners.

Probability fudging-drug companies with too many vaccinations, Randomized Controlled Trials (RCTs), airplanes safer than cars

In this article I cover some examples of probability fudging which goes on around us daily. The basic tenet of this post is:
When probabilities of two things are low (less than 1%), the comparison between these two things may makes you feel that your intended therapy or treatment improves things; but that doesn't mean it should be done, because 
1) there is a cost of doing interventions, of hassling a large fraction of the population to save a few. A crude example: We can be safer from a meteor hit by walking around in a body armor all day; but the probability of a meteor hit being low, it is not something necessary to do. There is a cost of making people mandatorily walk around in body armor all day, it is darn uncomfortable, and must be considered in the equation. And,
2) there is a safety profile of interventions, you may be doing more secondary harm by the intervention than helping the few who are helped.

HPV and rare disease vaccinations

[This part was written before 2021. Since 2021, I don't believe there is an HPV virus at all-virology is all junk science. However, even if there were an HPV virus, the vaccine is useless at best, as this shows.]

There is a lot of talk about Human Papillomavirus (HPV) vaccinations. Kids, especially girls, between the age of 10 to 15 years are recommended to get this vaccine. Let us look at the data, published by CDC here.

There are 79 Millions Americans (total population of about 300 Million) affected with HPV. There are 12 Million cases of new infections per year. Cancers attributed to HPV are 27000, of which 18000 are girls, the rest of 9000 being boys.

Since 1 in 4 Americans has the virus already, and 12 million get it every year, the virus itself can't be that bad. This is a classic case of measuring too much-if common bacteria presented in the mouth are measured, surely 1 in 4 have some particular "infection"...most Americans get on with their lives just fine, and HPV infection, even if they don't know about it, doesn't seem to be a big deal in everyday life. From this data, it is more common than the common cold virus-and you begin to wonder how (and why) they collected this data at the first place. But let's trust the data for a moment anyway.

The cases where you have severe effects (cancers) are interesting to us, 27000. It is a large number, but looking at the overall population of HPV infected people (79 Million), it is a very small percentage, about 0.034%.   Only 3 in 10000 people are getting cancers attributable to HPV.

The pharma companies say we can eliminate this tiny percentage of people getting cancers by injecting them with the HPV vaccine. The side effects of thee vaccine appear on the same page: Out of 67 million doses of vaccine, 25000 people reported some side effects, and 2000 of these were serious. The serious side effects are about 0.00025%, or about 0.25 in 10000. We must remember that many people may not report a problem even if their child has some side effects, so this number 25000 is likely to go up.

At first instance, it will look like the benefit of the vaccine, eliminating 3 in 10000 cancers, is about 10 times better than the serious side effects of the vaccine (0.25 in 10000). But if the disease is rare to start with, like this HPV-cancer, does it make sense to vaccinate at all? I find it ridiculous that we are going to vaccinate 9997 kids unnecessarily, to potentially save 3. There is tremendous hassle and cost involved in vaccinating children, and society has to bear that cost, one way or the other. Obviously what's rare and not rare is subjective, but to me, a disease which will going to happen to 3 in 10000 is quite rare, and we should not hurry to vaccinate kids against it. Couple that with the problem with this specific case where there's no clear indication that the HPV is causing the cancer (they are confusing correlation with causality, and assuming that the HPV vaccine with prevent cancers 30 years from now, which is very speculative an assumption) and you see that HPV should not be a mandatory vaccine.

Look at the distribution of 1-x, not of x

When probabilities are very low, the right distribution to look at is the 1-x distribution. That is the statistical trickery these guys are doing to convince us of the wonderful effects of the vaccine. If x is small, less than 0.1% (1 in 1000), you must evaluate 1) the risk of intervention causing more damage then the disease itself (the safety of the treatment or vaccine), and 2) just the hassle and cost of everyone undergo the intervention. Unless you have clear data that there is a strong benefit, don't administer vaccines (or other procedures).

Let us look at the 1-x distribution of the same data (placebo group).

99.9966% will not develop a cancer related to HPV if they are not vaccinated.
100% will not develop a cancer related to HPV if they are not vaccinated, but 0.00025% will get serious side effects.

By focusing on the "x" distribution, the benefit is magnified; but in reality, the real distribution of interest is the 1-x, which is a stable distribution, and doesn't change much by vaccinating our children. And we subject the large number of 1-x to an unnecessary intervention/vaccine.

Randomized Controlled Trials (RCTs) are not what they claim them to be 

I broke this down into a separate article here.


Airplane and Car driving safety

Airplanes are safe, driving in cars is safe. Most people know this, and will take a plane or car ride from a place to another without thinking about safety-they will only worry about costs and the conveniences and inconveniences when comparing the two. However, you have all sorts of bad statisticians comparing airplane safety to car safety, and concluding that airplanes are safer (or unsafer) than driving. The error there is that the 1-x is the real distribution of interest: the probability of survival. That is maybe 99.95% over 10 years of car driving  to 99.99% for plane riding, and those two are similar, dont you think? One thing is 99.99% safe, the other is 99.95% safe...we can agree that they are both quite safe. No one thought that planes are significantly safer or unsafer than cars. Both are safe, the 1-x is the real distribution.

Related articles: 

Monsanto, the real problem with GMOs

Lots of protests worldwide against Monsanto these days. The Genetically Modified crops (GMO, O is for organism-genetically modified crops are a special case of GMO, because you can modify animals also) leader has taken a lot of heat. But most people do not understand the real problem, here I go over it. The protests are okay, but are not for the right reasons.

Monsanto claims to modify crops genetically to improve yields and improve resistance to pests (these are the major two). Then they sell their own pesticides which go hand in hand with their seed. The farmer is bound by contract to plant their seed and buy their pesticides (Glyphosate or Roundup, and others). The farmer signs long term agreements to buy the seed from Monsanto (they can't even replant the seed from their crop).

The Science behind Monsanto (or all GMO crop companies) having done any good is dubious. 

Man's selection of crops, together with natural selection, has improved yields and resistance to pests enough that no one in Europe or Americas died of hunger since about 1500..what is Monsanto improving? The monopoly motivated city folk together with the unscrupulous scientists who work for Monsanto make up all kinds of data to show that their crops are better (higher yield, more resistance to pests). The US FDA falls for all this and the United States, the most important agricultural country in the world since 1800, falls for these people. Thankfully the monopoly of Monsanto in the US is countered by other GMO companies, who with equally bad science, provide a balance. And being a developed country the monopoly is controlled by a smart, agriculture favoring government and a good judicial system. So Monsanto prospered in the US, and the US farmer has not seen many problems, but unfortunately, outside the US, the governments are not that smart and the Monsanto monopoly becomes really oppressive for the farmers.

However, even in the US, there are some problems. The US court system in it's zeal of Intellectual Property protection has ruled against the farmer (see example here) but most farmers seem to be okay planting Monsanto seeds and buying pesticides from it. The stupidity of the Science behind the patents is not questioned-and Monsanto, like Apple, becomes another purveyor of patents and intellectual property rights. An Iphone is a completely different thing from a soyabean seed-one is a luxury, the other a necessity-and we start giving patents against farmers the food supply is bound to go down. The most friendly country for agriculture-USA-has fallen for the machinations of a wily monopolist. That Monsanto, a company which is valued at 50 billion dollars sues an individual farmer (in the link above) to protect it's Intellectual property is more a poke in the eye of the US patent office than the poor farmer-the whole patenting of seeds should not be allowed. The US Patent Office is taken for a ride by Apple and Microsoft, but now even the "farmer friendly Monsanto" is using it to win against farmers in courts.

Smith was very lauding of farmers-he said that they readily and willingly shared improvements in the techniques of agriculture with one another, they were free from the spirit of monopoly and "hiding my secret" which pervades in the city folk. Well with Monsanto, the city folk found a way to oppress the farmers!

Contrary to what many believe, the GMO crops do not have any health risks

300 million americans in the USA and several other large countries in the Americas have been eating these grains for a few decades and they seem to be living on just fine. The ignorant public is swayed by the health risk of GMOs and goes around protesting against Monsanto-the clear data than hundreds of millions of people eat GMO crop grains without major health problems is completely sidelined. The real problem-the bad science behind Monsanto and the contracts they impose on the farmers, is not talked about.

Everything around you is modified (genetically by man) anyway. The apples, pears, oranges etc. you see are selected by man to suit his tastes. Wheat, maize etc. are the same way selected for what we want. Darwin formulated his theory of evolution on this very basis-that in a few generation man could create new species and varieties of all kinds of plants and animals. His detailed "Variation under domestication of plants and animals", which is really the big book (two volumes) from which the data for the "Origin of Species" is taken, gives you a history of all domestic plants and animals, where they come from, etc. concluding that most do not exist in the wild state, and are modified by man be slow selection (and sometimes fast selection) to suit his needs or fancies. The point is-that we have been genetically modifying plants and animals since a long time, and there is little likelihood of us doing much wrong by "combination and permutation" of genes. The varieties of wheat, maize, etc. we see today in our fields are carefully selected and optimized for the highest yields, pest resistance etc..and the funkiness of Monsanto's science is really not needed at all to improve them, simple selection by man will improve the crops, plants and animals much better.

Stuff like exotic gene splicing, of putting fish genes in plants or a dog (which scares a lot of people, even the learned Mr. Nassim Taleb), are not cutting-edge science; they are a foolish scientist trying to create something new. The plant or animal which one creates by 'insertion' of foreign and very different genes will most probably die, and has an even lower probability of reproducing (a necessary thing to create lots of individuals of the species). This is covered well by Darwin throughout his book, and the second volume of it. Hybrids are difficult to form, and even more difficult to breed, is the constant message in his works.

In summary-the seeds Monsanto (and all other GMO crop makers) makes are not better than seeds developed by man without direct genetic modification (by artificial (man induced)  selection; over a few years, you get the same modifications...just that the process is slower, and we have done quite well in agriculture in Europe without GMOs). They do not give higher yielding crops or more resistant crops than what man already had (some minor exceptions may exist). The yields on French farms are not significantly lower than US farms (France has banned GMO), and no matter how much data is published by Monsanto, it should be taken with a grain of salt. If the technology of Monsanto is slightly better, or not better at all (my personal view), then the fact that Monsanto makes these massive contracts and monopolies is a reason enough for farmers not to want to plant genetically modified seeds.

Banning GMO crops is a good thing, and France (among several other intelligent countries) has not fallen for the bad science of this monopolist disguised as a cutting-edge science company, and I hope that other countries will follow suit.

Let the farmer produce without contracts and legal complications-it is the abundance of food which is the original cause of economic development of humanity.

One exception would be getting plants modified for specific illnesses/specific pests, which could have a genetic reason and solution; but that should be figured out by artificial selection by man; and there is not need for farmers to be paying expensive research fees to Monsanto. General statements like "our seeds are more pest resistant" (there are thousands of pests!) and high-yielding (marketing talk) are non-scientific and false.

Some validation for my ideas from researchers-details here.

Update 2023: Have realized now that Genetics is junk science, all of it. GMOs are totally fake. Gene splicing, insertion etc. are just simulations and models. Detailed article here.


Thoughts on mate selection in humans

As I have previously said in another post, I classify humans in two major groups determined by their GENETIC MAKEUP-polygamous and monogamous (there is another group maybe, the asexual human, but at this time, these two groups are sufficient to explain things...).

Mate selection in free societies, where females dominate in the selection process (males with sleep with anyone; the females are in control in free societies) is determined by this major classification. The polygamous females will choose polygamous males; the monogamous females will choose monogamous males.

I don't want to put human males in the black widow spider mate group-they do have control, but most of decisions on mating behavior are made by females in FREE and LIBERAL human societies.
This I say from my observations of humans around me.
You can throw away all those psychological compatibility tests, and all other crap which social sciences and psychology etc. tell you to follow (an example here, which made me write this post),  mate selection on a GENETIC basis is really selection by polygamous and monogamous females for males. And the GENETIC basis of mate selection is the only real and lasting basis-you won't last long with someone who likes to sing pop songs like you do, or other irrelevant habits and "things you have in common". Mate selection is robust, enduring and not dependent on silly things like preferences for music or food-the real robustness being GENETIC in nature.

See also-Genetic Affinity in Friendships

and
 Genetics-the mother of everything

Sanjay

On instrinsic affinity in friendships

I used to call this article 'genetic affinity in friendships'. But have now come to the conclusion that genes are a mental construct, don't really exist. The ATAGATCA singing geneticists make it all up.

However, characteristics are passed from parent to child. How? We don't know, the gene model is junk science.

Therefore I will call it 'intrinsic affinity' from now on.

I have noticed that I try to get along well with a particular kind of people. They seem to be of varied professions, upbringings, cultures, countries, races, etc...but the affinity is very very strong. It lasts for a lifetime, they are my friends for life. I see some common things in all these friends of mine-they are honest, truthful, monogamous (or at least serially monogamous) and at some level, "reliable" to me.

I will assert here that this "honesty" which leads to life long friendships is intrinsic. I have a natural affinity for people like this. This is for both men and women alike.

When we don't get along well with someone-I believe it is also a "intrinsic" clash at a very fundamental level. These others surely find other groups of people with similar internal makeups to hang out with, they are their intrinsic friends, but the point I want to make in this post is that our election of friends, and a partner, are intrinsically motivated, and not on other things. Nature dominates, Nurture is secondary for adult human beings.

You don't expect CEOs in suits and ties to hang out with people with more than 100 or more piercings on their body. There are exceptions, of course, but even our selection based on appearance and clothing style has a signature of intrinsic selection written all over it. It is safe to say that given no other information, you believe that your best friends will be people who will look or dress the most like you. Physical appearance is the easiest measure of similarity. Your phenotype is largely determined by your genotype.

Everywhere in the world I see this in action. People of the same kind stick together-and what do we mean by that? The only real similarity between two individuals is intrinsic. Animals do the same, as you might expect (we are a part of the group). When you walk out with your dog in the park, the dog reacts and responds to other dogs. It is interested in animals which look more like it is. In most cases I venture that the encounter is friendly; the dog may love you and everything; but would rather spend time with other dogs who it gets along well with (intrinsic affinity in layman's terms).

You see this with children. If you walk with your child in a mall she is interested in other children in the mall; not the adults. What's going on? The child is able to assess 'moving objects which are most similar to herself' and responds to them positively in most cases. That is intrinsic selection-you are interested in your look-alikes, your ntrinsic clones, other living being who are like you.

This is the reason why humans of the same age tend to hang out together. You can argue that they are equal in maturity, have the same culture etc. but because even kids and dogs who have no idea about maturity and pseudo-scientific words like culture are attracted to their own kind, it is easier to explain everything by accepting the intrinsic similarity (which in most cases will be phenotype similarity as well) argument.

As a general rule-all individuals (includes animals) try to find other individuals who are the most genetically similar to them.

Consider a couple of other facts. When you see orthodox Jews in New York City, Sao Paulo or Buenos Aires, you are struck with how similar they dress. That dress is a signature of their intrinsic similarity, the intrinsic signature of their group (and consequently their difference from others around them). The same goes for Gypsies all around the world, or the Native American tribes throughout the Americas-from Canada to Chile. Or the cowboy-rednecks in the southern United States, or the much smaller Amish community in North US. These are groups of people who are called so because they preserve their culture (a word which is a social sciences word, and quite imperfect)-they way they dress, the music, the way they talk, their physical appearance, etc; but when your look at them as simply  preserving their intrinsic group, it all makes scientific and biological sense, and becomes easier to understand. When I see these groups of people, or some aborigines in Brazil or India, I cannot help thinking that they really are a different species (sub-species) than me and my friends for all practical purposes-they are a different species than I and my friends. Some years ago I went to a private party-the people said hello to each other, and started drinking right away-without many words exchanged. I felt so awkward. Whenever you are with a group of people who seem to get along well with each other, and you feel like an outcast-you can be sure that there is a intrinsic similarity running among them, and you don't have that particular set of intrinsic makeup which makes them get along well with each other. I mean adults (let's say more than 25 or 30 year olds) and not children-who may not have a choice in selecting who they hang out or party with.

When a I see a Gypsy woman approach me for money, I am struck by  how different she is from me. I could call her a different species. Same goes for orthodox jews, people with 20 piercings on their face, or 100 tattoes on their bodies, executives working in banks, insurance and other fluffy sectors. I can give you dozens of groups like this who I believe can be classified as a sub-species of humans. They are so different from me-that I don't mind thinking of them as a different species than me. I am sure the feeling is mutual-they think I am an ET.

I have no intention of disparaging any of the groups mentioned-it is this diversity in humanity which makes life interesting. As long as there is no violence and aggression between the groups, life goes on just fine-and you can appreciate all these different sub-species of humans and enjoy the various different activities they offer as a group.

One must be careful, therefore, to talk about humans. There are many different kinds-do you think a scientist at NASA has much in common with an aborigine in Brazil or Africa? Yet they are both called humans. It would be like me talking about primates and thinking that monkeys and chimpanzees and humans are one and the same thing. I see this sub-speciation occuring in human groups at all levels-in day to day life, we hang out with people of our own kind, intrinsically speaking. Mind you that appearances can be deceptive-there's more to intrinsic similarity than just the way you look, although that is a good first indicator. Just like based on looks alone your domestic dog is quite similar to a wild dog, but you down deeper and realize that they are so very different! Or how dogs of different colors and spots hang out quite fine with each other, but suddenly will kill another dog. Some of these fights are territorial, but in the end, it can all be traced down to intrinsic differences between the dogs who group together to kill the "new" dog. The same behavior is true for humans-in hostile tribes, a new individual is killed. We have come a long way in intermixing, we don't kill or imprison people from new countries and tribes, because somehow we as humans collectively are able to realize that there are things in common you might have with someone from a different race, country, or tribe, far overshadowing the common intrinsic characteristic of the race (or tribe or country). This is how intermixing first started-you could trust people from other tribes and found that you have more in common with them, to actually go out and marry into that tribe. Note that primitive tribes are still marrying within their families (brothers with sisters, cousins, etc). In general, the more primitive and closed a culture (or racial group, tribe, country) the more the marriage within the same family, or same race, same caste, etc. The freest and most open societies, like in Western Europe and South America, are less prone to marriages of this kind.

It is obvious that a human being like you and me can cross with any of these groups to form babies-but that doesn't mean that they are not substantially different INTRINSICALLY. Crossing is a poor way to define species-witness mules, asses, and tiglions. I would guess that if a human male is crosses many many times with a female monkey, in maybe a few hundred thousand crosses, a healthy baby will emerge, just like in the cases of a tiglion or a mule.

We must also note that as different as we look like from outside -let's compare a cow, a monkey, a mouse, and a human-the internal organs and structure are very similar. You are beguiled by the appearance of the skin and the shell-but we without a skin (scaled for size of course, by taking different age sample of these groups) the internal structure of all these animals is very similar, and can confuse even an able scientist). Darwin talked a lot about this in his works.

The whole advance in modern medicine is based on this-we test on mice and when it works we move to higher animals. The obvious truth there is that drugs function similarly on all of us-and that means that we are far more similar that you would like to believe.

I seem to have digressed from the original subject of this post, but , you will realize that it is eventually the connection between all these varied animals, and then the groups choosing the ones most similar to them (their intrinsic 'friends'), crossing with them, preserving the children, and eliminating the ones which are different from them (their intrinsic enemies, or not-so-good friends) , is how we are forming new species in all animals.

In humans, you may object-saying that we must cross within the same family (brothers marrying sisters) to be nearest to you- but it is not necessarily true that you are intrinsically the most similar to your sister. From large amount of data with humans I can safely say that family bonds are weaker than bonds formed between friends (based intrinsic similarity is my argument). Of course, we should talk about adults here, not children; who are dependent on their families (let's say adults are all humans above age 25).

In mate selection, I see the same thing happening, the intrinsic affinity come really into play here. Your spouse or mate  is an extension of your friendships. I believe there is a lot in common between your spouse and your friends, they are the same type of people. Furthermore, you are selecting who you mate with at a very fundamental level, and you can see some very clear patterns here, where it is obvious that you are choosing someone who is similar to you, but of the opposite sex (why that is I don't know. This is obviously for heterosexuals, I don't know how this works for homosexuals, but should be similar). Tall people hang out and marry tall people, dwarfs marry dwarfs, and it is striking to me how couples seem to be so similar PHYSICALLY speaking. This can easily be extended to other animals-and comes from the same base 'intrinsic affinity with someone like me'. For humans, it gets more complex and fun to watch mate selection-heavily tattooed people marry heavily tattooed people, for example (because their love for tattoos is a very clear and obvious way for them to express their intrinsic makeup, just like tallness or shortness). People with lots of piercings also marry other people with lots of piercings. The underlying cause is biological; what you are seeing is the effect of the real cause when you see people with similar physical characteristics pair together. Heavily tattooed people marry heavily tattooed people not because they like people with tattoos as you will hear everyone say (which is a statement which doesn't explain the causality involved); but because there is something in their internal makeup which made them have so many tattoos in the first place, and they are looking for people who have these internal makeup, and in their case, it is easy to recognize because the genotype is expressed in the phenotype by these people getting lots of tattoos.

This intrinsic affinity we have at the individual level, and by it's natural extension at the group level, is the reason, the cause, for racial discrimination. Most individuals are designed to prefer their own race, and will exclude other races. Only when a high measure of intermixing has occurred, as in Brazil or Central American countries, that you see people of "one race" begin to  lose their majority and the majority becomes "mixed" or mulatto, as en Brazil. The intermixing is the cause of why racial discrimination goes away slowly. Why some people are not racists is more a surprise than why they are racists-how they became intelligent enough to realize that their outside physical appearance is not enough to determine their genotype in all cases-and that they can get along well with people who look substantially different from them (their own race). South America is hands down the most civilized and racially tolerant part of the world in that regard. A fraction of every race is designed to intermix, and why that is I don't know, but these are the ones who are able to realize that you have more in common with people of other races than your own race, or at least that race becomes a no-factor in friend and mate selection. Eventually this fraction begins to dominate the population in numbers, as in South America, and the area becomes non-racist.

This attachment at the intrinsic level for individuals, is the reason why nations take on a certain "character" of their own. It is in reality a genetic selection going on- e.g. people from France and Britain  have been moving between the two countries for many hundreds of years, and it is natural that people of one type will huddle together-and u can see the characteristic French or British trait in a substantial number of the citizens of each nation.

I don't want to bore you with all these facts and observations without attempting to draw some conclusions from them which you can use in your daily life. The big one here is that if you don't click with someone fast, let it go-the incompatibility is at the intrinsic level. They may be a part of your family, may play soccer with you, go to the same University you go to, but you may not have much in common with them to call them your friend. Similarly, do not judge people on their habits, their professions etc.; try to keep and open mind and you will find that you will make excellent, life long friends in groups you never thought you could find compatibility. The real attraction is genetic, it is beyond race, it is beyond the habits you might have common with others. Because it is genetic, it is not ephemeral; it is strong and will stay that way all your life. I have used this idea to quickly form friends, and I am sure that these friends will be my friends all my life.

When you don't "click" with someone, walk away quickly and cut your losses. This is even more important in mate selection-where mistakes can be very painful. Don't force friendships and relationships on people; and don't expect people who you knew all of your life to be your best friends. You might make friends very fast in a voyage in Brazil or Germany. Don't be shocked if your sibling doesn't care much about you anymore; that is what makes you associate with other people quickly! It would be a contradiction if all your siblings and cousins were also your best friends; this is a characteristic of a tribal society, not a civilized country with millions of people and millions of possible (intrinsically compatible) friends to choose from.