Jump to content
Sign in to follow this  
HomoSad

Polygenetics: Time estimate for change

Recommended Posts

If a particular trait is determined by having at least three mutations on six involved genes and this trait provides a strong survival advantage over those that don‘t have it -  how long will it take ROUGHLY till the trait has for example doubled in a given population?

I mean: Are we talking more of several generations or several hundred or even thousands of generations?

Is there any kind of online calculator to solve that kind of problem?

Share this post


Link to post
Share on other sites

Imagine animals, such as apes, that live in tribes. Do we count a single tribe as a given population, or do we count all tribes as a given population. If we are talking about all tribes, then their size, frequency of inter-tribal breeding, and the amount of survival advantage provided by the trait, will determine the speed. Of course also the initial size of the given population is important. Simulations can sometimes account for these things, but it's quite a lot of work to tweak all such variables to mimic reality (I think). If you just want a broad idea, online simulators should be okay.

I remember using toy models/simulations at university, but those were made in-house. You can play around with some simulation programs (important to run many simulations, as the outcome of each will be different): http://popgensimulator.pitt.edu/graphs/allele#! Or look for some other other gene frequency simulations. 

Maybe other people have more concrete answers (not sure if that simulator can do what you want).

Share this post


Link to post
Share on other sites
Posted (edited)

Thanks very much, I was all the time googling for a "genetic calculator" :) And this although I am familiar with simulations from my own study subject. That's called a fail I guess.

The trait I am looking for is psychopathy. What is your instinct: can a society that prefers violence and inequality (I guess that in unequal societies the abiliy to manipulate will have greater payoffs than in equal ones - as wealth damage can often not be undone in unequal socities while in equal society personal trustability and reliaility should have the greatest long term social pay off ) become more psychopathic in the genetic sense in the next hundred years?

P.S. Do you know a simulator that simulates the spread of a polygenetic trait in one population for simplicity? Because in my hypothesis only when at least 3 of this genes combine (meet) there is a chance that the trait of psychopathy really expresses, or lets better say expresses in a way that it provides a survival advantage because even non-psychopaths in the phenotyp sense with the said gene set seem to have survival advantage. I will need to get a lot of data (for example how much of this genes mutations are already there in the present population) and I have to make assumptions on how much of fitness advantage this genes really lend but I guess a project that is emotionally interesting is a good way to start to learn genetics.

Am I at least loosely right that if there is a fitness advantage in a particular combination of gene mutations than the growth of people who have the complete combination will at the beginning will be slow (because they rarely meet and the individual mutations on their own might not give an advantage) and than the speed at which they will meet and hence become positively selected will grow exponential over time?

Edited by HomoSad

Share this post


Link to post
Share on other sites

I don't think evolution, especially for animals such as humans, where each generation takes quite a while, and which have extremely high inter-tribal (national) relations, will suddenly have more psychopaths in the genetic sense in the next hundred years. Is there any reason to think psychopathy is determined three or only a a few gene variations?

About the fitness of a polygenetic trait that only increases fitness when all the right variants are in place: If they are not carried on the same chromosome, there inheritance is going to be a lot more difficult.

I don't know about a way to simulate such a specific example. Also there are too many confounding variables to give a clear picture and to answer your other questions, at least for me.

Share this post


Link to post
Share on other sites
Posted (edited)
22 hours ago, Dagl1 said:

I don't think evolution, especially for animals such as humans, where each generation takes quite a while, and which have extremely high inter-tribal (national) relations, will suddenly have more psychopaths in the genetic sense in the next hundred years. Is there any reason to think psychopathy is determined three or only a a few gene variations?

About the fitness of a polygenetic trait that only increases fitness when all the right variants are in place: If they are not carried on the same chromosome, there inheritance is going to be a lot more difficult.

I don't know about a way to simulate such a specific example. Also there are too many confounding variables to give a clear picture and to answer your other questions, at least for me.

I see why you are sceptic because in other mental problemes a lot more genes seem to be involved. here is the site that made the somewhat dubious claim that only 6 genes are involved in rising the propability (or known to be involved so fare:  https://en.wikiversity.org/wiki/Genes_linked_to_psychopathy ).

I know that is is mostly from small isolated populations that new species get created. My fear was however that the genetic make up of ALL humanity has already changed so that future changes can be quicker from now on, even with migration. Up to 5 percent of the Population have some form of psychopathy or sociopathy so the involved genes - which do not even trigger under every Environment - are propably not super rare genes.

There is no reason to think however that psychopathy is determined in the next three Generations I guess too. The fitness advantage of not beeing prone to cortisol Health stress should not be very extreme too.  (I saw in one of this genetic simulations you pointed me too that they work with fitness increases from a factor of 1 - Population does not change -  to 1.1 Population starts to change).

However I ask myself how fare politics should think into our "biological future" when deciding what a safe politics and economics should loook like. In Climate Change we try to convince everyone to think more fare than the next election term but it does not happen.

I know that the consumption of brain drugs (antidepressants, opiates) is very high in the USA for example -  and this could be indirect evidence of social engineering non-psychopathic people into a life stile they are simply not made for in a biological sense (and will not withstand is the long run).

Do you - by the way-  know any attempts to link the effects of poltics to gene changes for any kind - maybe in some small Island population/something more predictable than whole humanity?

 

P.S.

I am a bit slow in thinking. But if there would be anyway to link the genetic data of people they are giving so freely to th genetic heritage companies with the number of children they have at a given age than it should be possible to see if psychopathic gene combinations will become more likely. One would as well be able to compare more equal froms of capitalism like that of your Country with less equal forms such as the US. What one has to carefull about however is to calculate as well if the number of "unknown" extra-martial children is higher for psychopaths (fatherhood test). To have the link to the brain drugs it would be usefull to have a questionary about that.

Edited by HomoSad

Share this post


Link to post
Share on other sites

I don't know of any such studies. I also don't know if psychopathy actually increases chances to get offspring. Additionally there is no reason to think that psychopathy is something caused by specific genes, only that certain genes increase the risk (as of now, without enough evidence to support causal links, almost everyone has a chance to be(come) a psychopath, but certain gene variations can increase that chance). 

I don't see how 'brain drugs' are related to social engineering of non-psychopathic people (is it different for psychopathic people?).

To your last question, no I haven't heard of such studies.

Share this post


Link to post
Share on other sites
1 minute ago, Dagl1 said:

I don't know of any such studies. I also don't know if psychopathy actually increases chances to get offspring. Additionally there is no reason to think that psychopathy is something caused by specific genes, only that certain genes increase the risk (as of now, without enough evidence to support causal links, almost everyone has a chance to be(come) a psychopath, but certain gene variations can increase that chance). 

I don't see how 'brain drugs' are related to social engineering of non-psychopathic people (is it different for psychopathic people?).

To your last question, no I haven't heard of such studies.

Brain drugs such as calming agents or antidepressants can treat Symptoms of mental illness that are caused by chronic stress. It is claimed that psychopaths less often get mentally ill so they should not for themselve need or seek to get a prescription Treatment for a mental illness - and especially not a calming agent (they are adrenaline seekers).

In the case of Opiates the realtion is less obvious because they are hig consumers of illegal durgs and drugs that gives highs.

The relation between stress and mental Health is the following: 

Socioeconmic stress triggers mental illness in People that can get stressed and make their course worse (this bad effect of socio economic stress is statistically proofen for example for shizophrenia and the mental health of equal societies is generally and statistically proofen to be better than that of unequal societys ). As explained stress works completely different in psychopaths because they produce adrenaline but not enough cortisol as a Response. And the lack of the later is what should protect them from most stress related illness. Psychologcial Trauma can by the way be somatized and negatively affect the whole Overall Health so other illness besides mental illness might be as well more common in People who can feel stress. Psychopaths in contrast are extraordinarily resilient to punishment which again indicates that they are not prone to stress and Trauma.

If one can hence statisticaly link the prescription of drugs that are strongly related to treating illnesses of chronic cortisol stress (must not necesarilly be mental illesses which are the best candidates here, I have to think about this longer)- with the amount of children one has, one can propably skip the study of the genetic Relations for know and nevertheless has a first Impression of what geneticall is going on.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.