Rh gene

a reply to: Temudjin

Not at all. There are many factors thst can alter gene expression.

a reply to: chr0naut

So lets say before the labs, how long does it take for a mutation to take over lets say a tribe of 100 people ?

a reply to: Temudjin

Im assuming youre referring to a beneficial mutation in this scenario so with that in mind, its a pretty variable number because if the group of people in question is 100 at point zero there is no guarantee that the group in question will maintain such a strict number. In fact, its highly improbable. But realistically youre still looking at dozens of generations at a minimum and because of the nature of mutations, there isnt a guarantee that the entire population will have that particular mutation. Again, this probability is highly unlikely. Even in ancient populations such as the Khoi-San people of Sub Saharan Africa, there is no universality in terms of every beneficial mutation. Obviously there are some traits that have taken over the population such as skin color, hair type and eye color but even these are not guaranteed to appear in every member of the population in every single generation. Otherwise traits like albinism would not appear due to recessive genes. In other areas of Africa where Malaria is prevalent, not all members of a given population will demonstrate the genes for sickle cell, in Europe and Asia we see a multitude of phenotypic presentations from eye, skin and hair color to height and body fat and skeletal frame. The larger the population, the longer it takes amd the less likely a trait is to over take a population. Its one reason rates of obesity due to sedentary lifestyles and poor diets in westernized countries, especially so in areas of the US. In short, there isnt really a fast and hard rule or ascribable time frame. We can see in tra sitionary periods from H. Heidelbergensis to H. Neanderthalensis thst body types prevalent in HN populations took nearly 100 KA

a reply to: peter vlar

Now lets say a dozen of humanoids shared a trait, and it was incestuous would it give rise to more genetic damage like overgrowth, albinos, blood diseases, etc. etc. and if that family mated with a better genetic sample ( naturewise ) would the diseases like size etc. pass thru?

a reply to: Temudjin

Inbreeding results in homozygosity, which can increase the chances of offspring being affected by recessive or deleterious traits. There is a recent example of this in Australia. By the 4th generation(great grand children of the original breeding pair of brother and sister) there were rampant homozygosity deformations rampant in the children. It doesn't take long for deleterious recessive alleles to present in a profound fashion.

www.independent.co.uk... r-generations-of-inbreeding-8998115.html

www.sciencedirect.com...


ETA: Apparently the first link is too long to display properly. If you quote this post you can then copy and paste it into your browser to view it.

originally posted by: Temudjin
a reply to: chr0naut

So lets say before the labs, how long does it take for a mutation to take over lets say a tribe of 100 people ?

How long is a piece of string?

Really, there are so many factors relating to the spread of a mutation through a group that it would be hard to put any definite figure on it. Also, one would expect the numbers of the group to change over time as well.

So, assuming the mutation is heritable and advantageous, the starting number is 100, the average generation is 40 years, the average number of children of a union is 3, the mutation expresses in all offspring, ignoring mortality issues such as disease and average age at death is 80 years:

The first generation would produce 4 people with the mutation, three of those would breed and produce a second generation of nine individuals, who would breed to produce 27 individuals and so on.

By the 5th generation, after 200 years, there would be 243 breeding individuals carrying the mutation and 81 non-breeding ones carrying the mutation, but the total number of descendents from the original 100 would be 24,300 breeding descendents plus 8,100 non-breeding descendents.

Like Zeno's paradox, no matter how many carried the mutation, it would always be a small fragment (in the vicinity of 1/100th) of the total population. At no stage would the mutation spread to the whole population.

Of course, if there were different natural selection pressures, variable mortality ages, variable generation ages and variable family sizes as there are in real life, then this idealized mathematical scenario would be totally useless and wrong.

originally posted by: Temudjin
a reply to: peter vlar

Now lets say a dozen of humanoids shared a trait, and it was incestuous would it give rise to more genetic damage like overgrowth, albinos, blood diseases, etc. etc. and if that family mated with a better genetic sample ( naturewise ) would the diseases like size etc. pass thru?

Yes, there would be increased genetic diseases, quite specifically, the diseases that would arise from recessive genetic traits. Normally recessive traits are not expressed and are trumped by dominant traits, except where they appear on both chromosomes, implying that the identical sequence came from both parents. When identical sequences appear on both chromosomes, we call this homozygosity.

Recessive traits include: nearsightedness, night blindness, color blindness, grey eyes, green eyes, hazel eyes, blue eyes, blonde hair, light hair, red hair, straight hair, baldness, normal hairline (no widows peak), no dimples, attached earlobes, no freckles, thin lips, susceptibility to poison ivy, albinism, hemophilia, congenital deafness, deaf mutism and phenylketonuria (PKU) and there are other rare diseases, too.

(so much for Nazi genetics, all those blond haired blue eyed Aryans are not dominant!)

We can use numbers like the 'coefficient of inbreeding' or 'coefficient of relationship' to measure the amount of homozygotic genes as a percentage over the whole of the individuals genome. While this does not tell us directly about disease rates, it does tell us the effect, in genetic terms, of different types of inbreeding.

A list of human rates is shown below:

Mating Relationship = Coefficient of relationship (r)
Inbred strain = 99%
Identical twins & clones = 100%
Parent-offspring[5] = 50%
Full siblings = 50%
3/4 siblings or sibling-cousins = 37.5%
Grandparent-grandchild = 25%
Half siblings = 25%
Aunt/uncle-nephew/niece = 25%
Double first cousins = 25%
Great grandparent-great grandchild = 12.5%
First cousins = 12.5%
Quadruple second cousins = 12.5%
Triple second cousins = 9.38%
Half-first cousins = 6.25%
First cousins once removed = 6.25%
Double second cousins = 6.25%
Second cousins = 3.13%
Third cousins = 0.78%
Fourth cousins = 0.20%

(Incest laws usually concern the relationships where r = 25% or more).

Also, the issue of these recessive genetic diseases is negated in a single step where homozygotisms are essentially removed and normal dominant expression comes to the fore, i.e: a single mating with an un-related person will undo generations of the genetic damage of inbreeding, in the offspring of that union.

a reply to: peter vlar

a reply to: chr0naut

A big thanks!

U guys made my research in a couple of days.
]

RH negative factor is not found in animals though? Right?

a reply to: Stormdancer777

Was a clinical try to change blood from positive to negative, ask these guys they could answer, im doing research

That's just rude.a reply to: pheonix358