Assuming life had a single origin—which is the accepted version of events—every organism on earth is your cousin. You have a common ancestor with every bacteria in your gut, and with the the animal, or vegetable, fish or fungus you just ate.
Everyone on Earth is your cousin (2015)
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Re: Everyone on Earth is your cousin (2015)
#72Earlier quoted context omitted.
Also, if you go back a few hundred years there were relatively so few people on the Earth. I bought First Wife a posey ring from 1600s England. I was interested to know just how many people were around then. It was about 5% of the current population. The world was empty.
Well. There were fewer people, yes, but they also moved around a lot more. It's only comparatively recently that we've gotten stuck in our places and social structures.
People in 17c England didn't move much.
Re: Everyone on Earth is your cousin (2015)
#73Earlier quoted context omitted.
There is nothing more freeing than embracing nihilism. We're just sentient space dust, after all.
Totally. The concept of heat death made everything feel pointless to me (that was my moment). Heat death is well over 10^106 years away[0] but for some reason i was like wtf... nothing matters. [0] https://en.wikipedia.org/wiki/Heat_death_of_the_universe#Tim...
I find it it incredibly funny to worry about the heat death of the universe. That's so far beyond our scope of comprehension and the limits of the lifetime of the entire human race it does not matter in the slightest. It feels like the most absurd form of existential egotism.
Re: Everyone on Earth is your cousin (2015)
#74First cousins share 1/8 of their DNA, which is sort of meaningful. Second cousins share 1/32 of their DNA or about 3%, which is really marginal in terms of their being any resemblance or affinity due to DNA. By the time you get to third cousins the shared DNA is down to 1/128 or less than 1%. So I've lost interest in tracking down any relatives beyond second cousins.
I'm very ignorant about these matters but I thought we all shared the vast majority of our DNA? I mean as humans are we not all 99.9% the same ... DNA wise? What does the 1/8 mean in this context?
A child inherits half of the mother's DNA and half of the father's DNA. This is because in somatic cells chromosomes come in pairs, but when sperm and eggs are produced, the pairs divide and each sperm or egg contains only one chromosome from each of the 23 pairs.
Therefore, given that you have received one of each pair, the probability is 1/2 that your sibling received the same one of the pair. Thus, siblings share 1/2 of their DNA on average.
When you get to first cousins, each line of descent from the common grandparents is diluted by 1/2 from the grandparents that they do not have in common.
Thus Nth cousins share on average 1 / 2 ^(2N+1) of their DNA in the sense that the shared DNA is inherited from their common ancestor. This is the only part of their genome that would cause their phenotypes to be similar. Any other similarities between cousins is by chance or because their relatives may have married into similar ethnic groups with shared deeper ancestry.
Re: Everyone on Earth is your cousin (2015)
#75Earlier quoted context omitted.
What? I can't tell if this is a joke but the average person in the 1600s moved around a lot less than the average person today. I wouldn't be surprised if 80% of them never left a ten-mile radius.
Which persons are you referring to? People in the Americas, in Australia, in Africa as well as probably other places I'm forgetting about easily traveled hundreds of miles and both shaped and joined communities other than the ones they were in before.
I'm talking about the overwhelming majority of people who did not have a nomadic lifestyle or typically travel long distances.
By 1600, most of the world's 500 million people lived in what we would recognize as settled communities in modern-day India, China, Europe and the near/middle East [0].
Fewer than a million aboriginals lived in Australia and a few million in the US [1]. Nomadic lifestyles simply can't support anywhere close to the density achievable by even subsistence farming.
[0] https://en.m.wikipedia.org/wiki/List_of_countries_by_populat...
[1] https://en.m.wikipedia.org/wiki/Population_history_of_Indige...
Re: Everyone on Earth is your cousin (2015)
#76Almost every country was very homogeneous just 50 years ago, so your family tree wont branch out like that normally. USA is a bit different since it is a nation of immigrants, but mostly people barely even left their villages historically.
Not just the USA, the whole American continent is one big exception to that homogeneous countries rule. But if you were to single out a single country, it should probably be Brazil instead, being by many accounts the most heterogeneous country in the world. Fun fact: in the fake passport circles, "Brazilian" is a popular go-to nationality because no one will question a Brazilian nationality based on your face/race/color.
Re: Everyone on Earth is your cousin (2015)
#77Earlier quoted context omitted.
Another thing I find interesting is that your family right now are the most closest humans related to you. When you go back in time or forward in time, the relatedness dilutes.
Even then, you and your sibling could, statistically, share zero genes (you each get 50% from each parent and it is possible you each got a different 50%). Your own parents and children are the closest relatives you have since you are guaranteed to have 50% of your parent’s genes and same with your children.
Humans have approximately 30,000 genes. These genes are sequences that appear in our DNA which is divided up amongst our 23 chromosomes. Offspring receive these genes from their two parents so during meiosis we receive some genetic material from our mother and some from our father. There is about a 50% chance of receiving the mother's gene and a 50% chance of receiving the father's gene for each of the 30,000 genes involves. (The details are more complicated, see [1].)
So yes, statistically one could with probability of something like 1/(2^30000) receive a complete different set of genes than a sibling. In the real world, one will always share around 50% of ones genes with a sibling.
Re: Everyone on Earth is your cousin (2015)
#78> Writing this has really hammered home the point that humans are mainly a temporary container for their genes. In 150 years, all 7,100,000,000 people alive today will be dead, but all of our genes will be doing just fine, living in other people.
I really like that takeaway.
Re: Everyone on Earth is your cousin (2015)
#79Earlier quoted context omitted.
Totally. The concept of heat death made everything feel pointless to me (that was my moment). Heat death is well over 10^106 years away[0] but for some reason i was like wtf... nothing matters. [0] https://en.wikipedia.org/wiki/Heat_death_of_the_universe#Tim...
I find it it incredibly funny to worry about the heat death of the universe. That's so far beyond our scope of comprehension and the limits of the lifetime of the entire human race it does not matter in the slightest. It feels like the most absurd form of existential egotism.
Yeah that's fair enough. I care more about the end of my consciousness and my own dust turning to dust yet again than the heat death of the universe, something that's so far away, and asymptotically won't ever happen. Is it really the end if nothing can "experience" it?
Re: Everyone on Earth is your cousin (2015)
#80Pro tip, get the old folks talking, and take out your phone to record. Whatever they're talking about, even if they're talking about nothing at all. They'll all be gone soon, and having video of your boring everyday interactions with them is better than having only your memories of them.
> […] and having video of your boring everyday interactions with them is better than having only your memories of them.
How comes? To me, the most valuable things from the past are the memories. Not photos, video and stuff.