Humans reproduce on the average by the time they are 25 years old. Meaning that each generation is separated from the previous one by about 25 years.

1400 divided by 25 is equal to 56 (56 generations have passed since mohammad)

1400 / 25 = 56

Each child gets half of his/her genetic material from the father, and half from the mother. Therefore, each generation of "seyyed" are only half as much related to mohammad as the one before. This is assuming that in each marriage, only one spouse is a "seyyed".

In that case, each person currently living, is related to mohammad by a factor of 0.5 to the power of 56.

1/2 to the power of 56 is equal to 1.38 times 10 to the power of -17

in other words, each person alive today who claims to be a "seyyed", is related to mohammad by a factor of 0.0000000000000000138

That is quite insignificant indeed !!! So basically, being a "seyyed" means NOTHING ! Because those who claim to be a descendent of mohammad, are just as much descendents of 28 (56 generations of a "seyyed" marrying a non-"seyyed") other people who were NOT "seyyed" !

even if we assume that half of a person's ancestors married another "seyyed", that would still mean that they are related to mohammad only by a factor of 0.00000000373

The Human genome contains 3 billion base pairs

4 chemicals named Adenosine (A), Threonin (T), Cytocene (C), and Guanene (G), pair up, to create one piece of DNA

(A) pairs up with (T)

(C) pairs up with (G)

Each one of these pairs is one piece of DNA, and the human genome contains 3 billion of these pairs.

3 billion multiplied by the factor by which a "seyyed" is related to mohammad is equal to 0.00000000414

300000000 * 0.0000000000000000138 = 0.00000000414

That means that not even A SINGLE PIECE of a "seyyed" 's DNA is likely to have come from mohammad !!!

even if we take the second scenario

300000000 * 0.00000000373 = 1.119

ok, in that case ONE of your pieces of DNA may have come from mohammad !

BIG DEAL !

I am not talking here about the inheritance of traits, which follow the Mendelian laws of inheritance. I am talking about "being related to someone". for example, you are more "related" to your brother or sister, than you are to your cousin. for example, your "pesar khaleh" 's father comes from a different family than your own father, therefore you are not related as closely as your own siblings.

each generation that passes, one is half as related to the previous generation. for example my mother is a descendent of my maternal grandparents. but my father is not. therefore half of my chromosomes, having come from my father, are different than those of my mother.

my own children's chromosomes, will be half mine, and half those of my wife. therefore their chromosomes will be 1/4 those of my parents.

(lets ingore chormosome cross overs, since they are rare)
this is something different than the inheritance of traits. because my wife may have the gene for a particular trait, and therefore the probability of that phenotype showing up in our kids will be different. but assuming that the gene pool we are looking at is large enough, and that there isn't any inbreeding, then you can assume that the actual chromosomes of two "unrelated" people came from different lines of people.

so, the probability that any one of the chromosomes of someone claiming to be a "seyyed", actually came from mohammad, is next to zero.

lets say MM is a chromosome pair from mohammad.

and lets say ww is a chromosome pair from his wife.

MM **X** ww

and you get Mw in mohammad's child

now lets see mohammad's child and his/her spouce (remember, we are looking at chromosome pairs, not traits)

Mw **X** SS

and mohammad's grand kids will be

MS

MS

wS

wS

so as you can see, half of mohammad's grand kids already do not have that same exact copy of that particular chromosome as mohammad did.

now repeat that for 50 generations, and you will see that a person calling himself or herself a "seyyed" is dillusional !

Hala boro delleto ba een khosh kon ke to mas'allan joone khodet "seyyed" hasti !!!