They found a genetic bottleneck of a couple hundred individuals some hundreds of thousands of years ago so that was probably worse
It is remarkable to imagine that every person alive now, or that's ever been alive, is descended from this same tiny group of beings. And all of this drama occurs in a remote spec of dust orbiting and average star of an average galaxy of 100B stars, among 100B visible galaxies. Even if we had Star Trek level tech, we'd still be approximately as insignificant.
And what is significance anyway? What determines whether something is significant?
Most often, the answer is 'to me, the guy making the observation.'
In that sense, that tiny speck of dust in our corner of the galaxy is very significant. At least to me.
A beneficial mutation followed by rapidly outcompeting other populations might look similar.
With same reasoning, it's not hard to think we are not alone in this universe, given the sheer scale of cosmos.
If you look at bacteria even, there's a lot of genetic transfer beyond just strict parent/child relationships either just directly or via viruses or other things I'm sure I've never heard of.
The earliest life was probably more like some kind of soup of self-replicating things, closer to a chemical reaction than biological, and then it would have been kind of a sliding scale over a long period of time before we get to anything that really looks that much like "<this> organism begat <that> organism".
The entire concept of organisms themselves are an abstraction over the truth, that kind of works for today's world, but probably less worked when things were new and interesting and messy.
There's probably nothing special about life and it's everywhere where water is warm.
First it starts to stink, then it gets fuzzy, then it starts to stink worse as the irregular fuzziness in the surface is replaced by geometric patterns spitting light and clouds of smoke. Eventually the surface is suddenly awash in fire and burnt black.
I just mean: at some point there was a pool (or ocean, or ocean with hotspots, or a beach with chemical goo, or etc.) of stuff doing weird chemical or physical things that we would not call biology, and over a period it moved way more towards something that we _would_ call bioloy. But it was not a hard and fast cut off, where <here> is the first living thing, one cell and then it grew and replicated. It was likely a stew of goo all intermixed at various concentrations and states that what we'd call life messily transitioned out of over such a period that there _was_ really no first living thing that you could realistically point to, because life is not well defined enough for that to make sense.
convergent evolution is a thing, even pretty common (e.g. see crap like animals)
and while very rare and unlikely different species can "merge" especially if we speak about relatively simple live form through the more complex the more problematic and limited it gets
through that isn't the relevant point I want to make
The point I want to make is that the linear tree few of evolution often presented in documentations is wrong, species diverged but also reconverged all the time. E.g. neanderthal might have died out but to some degree also mixed into what later became homo sapiens sapiens.
This might seem irrelevant for anyone not studying this topics, but it isn't as the tree one survives the other dies out view is often one of the building blocks of white supremacist race theory (which theoretically also doesn't make sense even if evolution is a clean tree as they extend concepts from inter-species relation ships to ethnic groups which average difference in DNA is too small to call them different races, but it's not like such people care about since).
There were many more humans alive at all points in time than the "genetic bottlenecks" suggest. It's just that their lineage ended at some point later, and wasn't passed on to modern humans.
Say, there were not "many more", but just like 15% more. Like 1150 alive, and descendants of 1000 of them did not die off completely. Sounds plausible.
This is true even today, but back in the original "state of nature", death for all sorts of reasons was way more common than today.
Run that through a few thousand generations, with wars, genocides and epidemics, and you get big numbers.
The other options is that there can be while groups of humans in a distant place alive at the same time, but they didn't survive long term and didn't re-mix with the "bottleneck group" at lest not in a way detectable genetically (idk. how precises the methods in question are).
The point here isn't that a genetic bottle neck implies the presence of other humans, but that it doesn't say that there can't have been other humans, just that other humans genes didn't carry forward until today.
> a 2023 genetic analysis discerned such a human ancestor population bottleneck of a possible 100,000 to 1000 individuals "around 930,000 and 813,000 years ago [which] lasted for about 117,000 years and brought human ancestors close to extinction."
And relatedly...
> A 2005 study from Rutgers University theorized that the pre-1492 native populations of the Americas are the descendants of only 70 individuals who crossed the land bridge between Asia and North America.
> The Neolithic Y-chromosome bottleneck refers to a period around 5000 BC where the diversity in the male y-chromosome dropped precipitously, to a level equivalent to reproduction occurring with a ratio between men and women of 1:17.