/sci/ - Science & Math

we're all inbred

where are you getting these figures?

>>2310921
They're just estimates.

2^9000

Those numbers assume that everyone has a different mom and dad. It does not take into account the number of children to parent, or incest. Probably some more stuff also, but alas I am tired.

>>2310929
No, those numbers simply assume that none of your ancestors repeat.

>>2310936
Thanks your explanation was more what I was aiming for.

My parents broke up. So those numbers are inacurate, since my father and mother both have new girl-/boyfriends.
Thus I have two mothers and two fathers.
(Actually 3, but that's another story.)


Also, what about orphans, they have no parents whatsover. Though you'd have to factor in adoption by gay couples and the likes.

I beleive I can be of some assistance

if you take 2x10^5 years and divide it by the approximate years per generation you get about 9000 (although I used 25 years and got 8000 - besides the point) generations... all good so far.

and yes 2^9000 is about 1.86x10^2900 or so... a big number.

You have been confused and made a fatal assumption.
You forgot about death...

People die before they procreate or infertile or just die.... There would have been that many ancestors if every single one of them reached fertile age and procreated....

You've also ignored mass extinctions (about 70K ago a HUGE volcanic eruption (lake toba caldira) killed a shit load of life off) and other things like plagues and lions.

When you make calculations you must incorporate assumptions....

>>2310965
I can't tell if you're insanely retarded, or just a troll.

Two human beings combined genetic code by fucking to make your body. Two human beings combined genetic code by fucking to make each of the human beings that made you. This continues to extrapolate for every generation. Two people per person, to the power of however many generations you're calculating.

>>2310975
>your ancestors didnt procreate
>hurr durr durr

>>2310975
All of those things were taken into account in the estimated total number of people who have ever existed (about 110 billions).

That huge number there is the number of ancestors you would need to have if no one ever fucked anyone they were related to.

>>2310912
wincest

>>2310912
>Can anyone explain this shit?

You don't know wtf you are doing.

wincest

>>2311020
Would you care to explain the fault in my reasoning?

>>2310912
>Makes up random bullshit

>asks people to explain it to him

>>2311030

>>2310975 seems to explain it pretty well

>>2310985
>I can't tell if you're insanely retarded, or just a troll.
Wow, from this I can tell that you're clinically retarded. I didn't even consider anyone taking me seriously, I was just talking bullshit..

But that's /sci/ for ya..

Reason is at least mild incest. If every ancestor is unrelated, then theres 2^n ancestors, but as cousins, 2nd cousins, 5th cousins, etc make babies the family tree stops spreading out

>>2311047
200,000 years is the generally accepted length of time that homo sapiens have existed.

Getting 9,000 generations from that is simple math.

Extrapolating the number of ancestors that should exist for an individual, over 9000 generations, is as simple as inputting 2^9000 into a calculator.

110 billion people having ever existed is an estimate that I found in an anthropology textbook published in 2004.

>>2311058
>Thus I have two mothers and two fathers.

Unless 4 people combined genes to make you, you have one mother and one father.

>>2311020
You do realize that, since people were not capable of traveling great distances to find a mate for most of history and thus were limited in their selection of partners to those living in the same geographical area, that our ancestors must have been limited to a relatively small gene pools?

>>2311055
No, it doesn't explain it at all. The guy who wrote that post completely misunderstood what he was reading.

>>2311060 explains it.

Also, there is no way that we could know how many people have existed "ever." Our fossil record only preserves those who died under certain, great conditions, so our fossil record is nothing compared to what has actually existed.

>>2311075
>Fossils

Dude, 200,000 years is not enough time for bones to undergo mineralization. Even so, even if 110 billion people was inaccurate by ten entire orders of magnitude in either direction, it does even come slightly close to the astronomical number of ancestors you should have.

You are the product of an insane amount of incest.

>>2311075
>thinks we found fossils of 100 billion people, then counted them to figure out population
>doesnt know what an estimate is

God DAMN /sci/ is STUPID today.

Work the other way in time. You start with a small population, and by having a birth rate higher than 2, it slowly becomes a large population. Then one confused little guy in the latest generation assumes that EVERYONE has UNIQUE ancestry, i.e., that none of them are related, and none of your ancestors were ever related either, and thus, the number of ancestors must have been "xbox hueg omg".

Herp derp. We all have common ancestors, and that 2^N bullshit is incredibly wrong.

tl;dr You're double-counting SO DAMN HARD

>>2311090
I know the number is wrong. I think you're missing the point. 2^n is the number of ancestors you would need to have if none of them were related (if no inbreeding ever took place).

The entire point is to illustrate how much incest has occurred over the course of human history.

I was looking for an anthropological explanation as to why we fucked our relatives so much.

Many clans did systematical incest. That's how we figured out it's not the healthiest thing to do.

And cousin on cousin isn't actually regarded incest, neither by the law nor by biology.

And if your family doesn't do it systematically, having children with your own siblings won't result in any kind of damaged children.

i should beat you like a ginger step-child

>>2311102
I think you're confusing "inbreeding" with "breeding". Think about it. ALL species mate with other members of the SAME species, so they obviously share common ancestry. Now you're all saying "hurdurrr incest and inbreeding"

By this definition, what ISN'T inbreeding?

>>2310912

I think you're going after the wrong thing here. 2^9000 is a very rough estimate(since it assumes the no one dies for 200,000 years) of how many genetic relatives you have ever had.

But ancestor means biological mother or father. Hence 2*9000=18,000. Still a rough estimate, since at some points a person could be the parent for two generations.

You're welcome.

>>2311151
>post troll line pic
>troll
Both of your assertions are fallacious.

>>2310912
yeah, but one instance of inbreeding N generations back reduces that number by about 1/2^N. So if you have grandparents who were second cousins, the number is reduced by 1/2^4 or reduced to 15/16 of the original number, and that's ignoring the fact that there is undoubtedly MUCH MUCH more inbreeding.

If you're wondering how I arrived at that equation, your grandparents are two generations back, and as second cousins they share a common ancestor two generations earlier, making inbreeding four generations back from you. So this means your dad's, e.g., ancestors remain unaffected. So 1/2 remains. Then your maternal grandmother on one side has unaffected. So 1/8. Same with your grandfather on one side. 1/8. This is 3/4 unaffected.
Now your grandparents have some unaffected people as well in the 1/32 realm on either side (adding 1/16), but then they have exactly the same ancestors for one part of the tree. This part is 1/16 of your tree.
Basiaclly it comes out to approximately 15/16 being unaffected and 1/16 being 100% redundant.

Now imagine this inbreeding having likely occurred SHITLOADS in the first few thousand generations, before theer were many humans geographically dispersed, and they lived in small tribes during the ice age that intrafucked constantly.

>>2310975
HOLY FUCK CAN YOU LOGIC FAIL ANY HARDER
The death of someone before procreation literally DOES NOT AFFECT HOW MANY ANCESTORS YOU HAVE, YOU STUPID FUCKNUGGET

That being said OP is still retarded, too.

>>2311157
>implying ironic trolling
>troll

>>2311151
HAHHA your post is asserting that everyone has only 2 grandparents, 2 great grandparents, 2 GGgrandparnets, and so on (you know, 2 per generation as is stated in the expression "2*9000")

>>2311170
>FUCKNUGGET
This pleases me.

>>2311069
That sounds interesting. Could that be the reason why people from different regions of the world look different? This definitely needs further research.

>>2311195
PENISWRINKLE

>>2311213
>Could that be the reason why people from different regions of the world look different?
DING DING DING DING DING!