
A tiny sea creature is the earliest known step in humans’ evolutionary history - diodorus
https://www.researchgate.net/blog/post/meet-your-earliest-known-ancestor-saccorhytus
======
NamTaf
What I find fascinating about this is that humans and many other branches of
the tree are Deuterostomes[1], which means that when the cells first divide
the first 'hole' goes on to form the anus [2], rather than the mouth. This is
in contrast to the Protostomes where the first hole forms the mouth.

I mean obviously it makes sense that a single-holed animal used it as a mouth
- the anus has no use without the mouth - but (in my naive understanding) it
means that somewhere beyond this ancestor, certain groups of vertibrates split
and went in opposite directions despite both being (presumably) decended from
this thing.

It fascinates me that there was some mechanism to cause this, rather than all
animals forming in the same order, if we did indeed share a common ancestor
that only had one entry/exit hole.

[1]:
[https://en.wikipedia.org/wiki/Deuterostome](https://en.wikipedia.org/wiki/Deuterostome)

[2]: The clever observer will note that this means that technically, very
early on, each of us is little more than an arsehole ;)

~~~
derefr
Personally, I think it's easier to understand the deuterostomes: the "mouth"
will benefit from being controlled by input from sensory organs, and those
need to be on the outside of the body. Thus, a natural bending of a flattish
body-shape into a horseshoe, with the mouth on the outside of the "bend."

Also, a fun fact to go with yours: vertebrates are triploblasts. That means,
when we first fold over (gastrulize), our cells differentiate into three types
--one on the "inner wall" of the fold, one on the inside of the body, and one
on the exposed "outer wall" of the fold. In other words: we're all tacos!

Another, perhaps more-weird-than-fun fact: our DNA is basically three separate
"code bases", one for each layer. It is much easier for a given feature to
evolve by differentiating from similar tissue proteins in its own layer, than
in another layer. (In fact, to do otherwise, the resulting proteins still have
to "start off" in their ancestral layer, before "migrating" during
development.)

Anyway: our brains--which you'd think of as an "internal" organ--are actually
part of the ectoderm, and in lower organisms, the first thing that the
ectoderm is, is skin. So, your brain (and your nerves, your spine, and most of
your sensory organs) are all effectively "kinds of" skin tissue. Your nerves?
Skin with capacitance. Your spine and teeth? Calcified nerves. The reward
centre of your brain? Modified skin pigmentation cells. Your retina: _also_
skin pigmentation cells. Your iris: modified retinal cells.

Basically, evolution always starts its feature branches with a bit of copy-
and-paste programming. :)

~~~
jacobush
So what you are saying is that nature ALSO shuns multiple inheritance? :)

~~~
zbyte64
Yes, but have you tried reading the codebase?

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astannard
A heard about this, it has a large mouth that it excretes though. I know a lot
of humans that still do that

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bluetwo
The cynic in me has doubts whenever Chinese scientists claim China is home to
the missing link.

~~~
eliben
I imagine if this was discovered in, say, Argentina, then there'd be a good
chance of some Argentinian scientist participating in the discovery.

Call it the anthropic principle of archeology :)

~~~
handedness
I can't speak for the GP, but one might make a reasonable distinction between
the reliability of findings that come out of Argentina as they compare to
those from China.

Edit: Someone doesn't appreciate this comment. Astute professional analysts
the world over know that official figures that come out of China are among the
least reliable on the planet.

And while scientific misconduct is not unheard of anywhere, China's hardly a
shining example in that regard.

Lastly, good Chinese research agencies themselves are having a difficult time
keeping up with numerous bad actors who are doing their best to fraudulently
publish papers.

This isn't xenophobia, it's a fair appraisal of the sometimes inconsistent
qualities of the world's societies.

~~~
jsnathan
What kind of misconduct? There is a big difference, for example, between
plagiarism and fabricating results.

And which percentage of the researchers are involved in this? 1%? 0.1%? 0.01%?
Do you have any studies you could link to that in any way quantify this?

China's research spending and number of research articles produced today is
second only to the U.S. There are always going to be some bad apples among
that many researchers. That should in no way discredit the rest of the
profession.

~~~
webmaven
Last year, 80% of the applications for new pharmaceuticals in China were found
to contain fabricated, flawed, or inadequate clinical trial data:
[http://www.sciencealert.com/80-of-the-data-in-chinese-
clinic...](http://www.sciencealert.com/80-of-the-data-in-chinese-clinical-
trial-is-fabricated)

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abbiya
It looks like chest breaker from alien

