When you marry,
usually you take on your partner's surname or your parter takes on yours.
Two people with different surnames become
two people with the same.
One surname spreads, the other one goes...
...extinct? Usually not.
There might be siblings, cousins,
strangers who happen to share the surname,
to carry it on for the one who lost it.
But if one person fails to pass on the surname,
so might the others.
In fact, every now and then
entire surnames do go extinct
when its last bearer passes away
without passing it on.
According to the Daily Mail,
in England and Wales, 200,000 surnames
were lost since 1901.
You can find lists of endangered surnames
on websites such as Ancestry.com and myheritage.com
Ancestry counts surnames with less than
50 carriers left as endangered,
which in England and Wales,
would currently be names such as
Pober, Mirren, Febland (heh, Febland),
Nighy - N-Nighy?
While some of these names might be more of a loss than others,
it's sad to think that they might all cease to exist within a few generations.
Back in the days, new surnames were created as well
based on someone's job or father's given name or where they came from.
But that doesn't really happen anymore,
not on a large scale, anyway.
So more surnames are lost than new ones are being born.
Keep this experiment going long enough,
and we will all end up with the same surname eventually, won't we?
When we look at Earth's more ancient civilizations - even more ancient-
intensive research reveals that most Chinese surnames in use today
were handed down from thousands of years ago.
While historically about 12,000 Chinese surnames have been recorded,
only a bit over 3,000 are currently in use,
a reduction of 75 percent!
And only a fraction of those are taking over a majority of the entire population.
The three most common surnames in mainland China are Li, Wang and Zhang,
which make up for more than 7 percent of the Chinese population each.
Together they belong to close to 300 million people
and are easily the most common surnames in the world.
In China, the phrase "three Zhang, four Li" is used to say just "anybody."
So after thousands of years, the Chinese people aren't down to
one all-dominating surname, but several.
What's going on here?
This effect can be shown in a simulation.
What you see here is the result of a Galton-Watson process,
which maps out how the distribution of family names changes over time.
It starts out with a very large number of unique family names
each represented by a different color, and after 40 generations,
or around a thousand years, ends with the ones which are left.
When you look at the very end there,
what you see is very similar to the Chinese situation.
The top three names take over 20 percent of the cake.
But the question is: if we keep the simulation going,
will we end up with only one surname?
Mathematically, the entire population does converge to only one surname.
But in real life, if we start out with, say, 10,000 surnames,
(and there are actually much more than that)
after 40 generations we'd still be left with over 400.
Okay, how about 200 generations?
Still 93 left.
While the less frequent names are dying out quickly,
the more frequent ones become so widely spread
that humans will probably cease to exist before they do.
The probability of extinction of
a unique family name that is carried by only one young couple
is 45 percent, at least in the West.
That's the average likelihood of them having no children
or only children who won't pass on the family name.
But the likelihood of a family name which is held by multiple couples
going extinct within one generation is 45 percent to the power of the number of couples.
So with a few more people sharing a surname it becomes very unlikely very quickly
that this surname should disappear soon.
If you want to know how often your family name is currently in use,
you can find that out on websites such as Forebears.
According to the US Census Bureau,
the most common family names in the US are currently
Smith, Johnson, and Williams,
which together make up for around 2 percent of the entire US population.
That's, of course, not very impressive to China.
In a way, you could say that on this timeline, the US is somewhere here
while China is already over there.
As fewer family names become more widely spread,
we might follow the Chinese feat and become more creative about given names.
So instead of Tim Smith,
you might be called the TalentedPeaceful Smith.
And, instead of Tom, I might be called The Rest of Us.