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Comment by qiqing | Hacker News Reader

Excerpt from the article, "The researchers noted that female adult chimps made and used spears more often than adult males. The males relied more on their size and strength for hunting. Female chimps are almost always hindered by infants that ride on their backs or bellies, so spear hunting is far more effective for them than attempting to chase down prey."

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Interesting. I wonder if female child ~~bearing~~ holding contributed to our move to bipedalism.

There is speculation that the baby sling did. http://www.independent.co.uk/life-style/history/prehistoric-...

TIL how long baby slings have been around.

"Before the invention of the baby sling, dated by Dr Taylor to at least 2.2 million years ago, when human ancestor head size suddenly began to increase, physically mature infants were more likely to survive, because caring for slower-developing immature ones was difficult, uneconomic and often dangerous. Mothers holding their infants were more vulnerable to attack from predators or other humans than those using baby slings. They were also less able to perform other more economically productive tasks.

Most importantly, the invention of the baby sling artificially lengthened human gestation, said Dr Taylor."

That all makes sense as a theory, but is this fact based on hard evidence or merely academic speculation?

2.2 million years is an awful long time ago, and I didn't think we had that much evidence about humans habits and culture dating back that long ago.

Exactly what happened roughly 2.2 million years a to explain this evolutionary change?

That's the thing. Most of the evolutionary theories about how something happened 2 or 200 million years ago are just on the level of speculation. That's one of my gripes about evolution ... the field attracts a lot of pseudoscience (such as evolutionary psychology) in the form of "explanations" for various phenomena we observe today, or how a transition happened.

The truth is no one actually knows, or can test most of the theories that seem like they MIGHT be true but could also be fanciful speculations by researchers. That something was found is a fact. How it got there is largely speculation, but I'm surprised how often these theories are taken seriously, not just by the public but by other scientists.

Real tests include statistical significance, like exploring the fossil record across continents, simultaneously corroborating the theories of continental drift and common descent. Allopatric speciation can be discovered this way. You need a bunch of data points or functions of them, that should be independent but are highly correlated. That is what supports a theory, in the Fischer sense.

Here is an example: horse fossils are found physically above t-rex fossils 99.9% of the time, and in the remaining cases, the rocks show evidence of upheaval in that area. Or, radiometric dating vs the superposition principle. If 99% of the data samples agree, that is extremely significant. That is how you prove theories.

I think the bigger mistake is to claim the invention of the baby sling caused our lengthened human gestation: it gives no selection pressure in favour of lengthening our gestation period, it merely removes a selection pressure against it.

Is the field of EP completely pseudoscience?

EP is obviously not completely pseudoscience, but it has a few global problems. It's often forced to test hypotheses about things that happened long ago, which is hard and can lead to weakly supported conclusions. It also adopts the conceptual framework of cognitive psychology, which can be a bit of a grab bag in terms of falsifiability because it is so heavily reliant on "indirect observation." Finally, it frequently deals in topics which are flashpoints for controversy, which invites unusually stringent examination and rejection from people with some personal or political or religious agenda.

Yeah, it also blunders around taking the status quo as something that has more evolutionary causes than cultural ones. And thereby ignoring eg: the patriarchy as a cultural system, and looking for explanations of its effects in genes.

In this it reminds me of the science of the early 20th century that took race as a mere fact, and tried to explain it.

You are mixing up proving the theory of evolution and using the theory to make speculations about the past. The speculations are only taken as seriously as the evidence they are based on. The last time you made a blog post you complained about the evolutionary psychology behind a loud female orgasm. I had to look it up for you that it is seen in other apes TODAY and since other things prove (with statistical accuracy) that we have a common descent with other apes, these speculations are viable.

Where is this supposed proof or strong evidence for the speculations? "Viable speculation" is not the standard in science for believing things to be true, and using them as a basis for conclusions.

This is similar to how human civilization formed. Areas of plentiful food have no need for farming or saving up food as wealth thus, it is only in places where food/resources are less plentiful did technological civilization develop.

Also, I've heard the theory (I don't know if it's true) that while Chinese invented porcelain and used it for containers (cups, plates, etc), Europeans never did, and ended up inventing glass instead (and windows, microscopes, telescopes, ...).

They talk about this on the British panel show Qi:

https://www.youtube.com/watch?v=N0OhXxx7cQg&ab_channel=solip...

Huh, I just read this theory yesterday in Nation by Terry Pratchett. I'm going back and reading the few books of his I missed.

The Road Not Taken...

http://pastebin.com/aJQfubrK

Telescopes were brought into Europe by Arabs living in what was then Iberia, Sicily and a few other places.

As well as many farming new technologies like irrigation for example.

Not quite - http://www.space.com/21950-who-invented-the-telescope.html.

Ok, it seems I got that wrong.

However I was right remembering that Arabs had something to do with optics, as the base findings trace back to Ibn al-Haytham (965).

http://en.wikipedia.org/wiki/Alhaze

Also just as general information for anyone curious about it, in the process I've found out a list of Arab inventions.

http://www.independent.co.uk/news/science/how-islamic-invent...

That's inaccurate. You should check out "guns, germs and steel".

That book illustrates one theory. What I stated is the theory taught to me as a student by the anthropology department at UCLA.

Edit:

I take that back. I just read the synopsis on wikipedia. The books' theory is exactly inline with my statement.

"The first step towards civilization is the move from nomadic hunter-gatherer to rooted agrarian society. Several conditions are necessary for this transition to occur: 1) access to high protein vegetation that endures storage; 2) a climate dry enough to allow storage; 3) access to animals docile enough for domestication and versatile enough to survive captivity. Control of crops and livestock leads to food surpluses. Surplus frees people up to specialize in activities other than sustenance and supports population growth. The combination of specialization and population growth leads to the accumulation of social and technologic innovations which build on each other. Large societies develop ruling classes and supporting bureaucracies, which in turn lead to the organization of nation-states and empires."

There's an interesting set of forces when it comes to "early stage" innovation (imo). On the one hand what you say is true...sheer necessity forces innovation. On the other hand if there's plenty of food one can save food and use the time not spent hunting/gathering to invent/build new technology.

That's pretty much the economics point of view. Save+invest->innovation/technology. Catch a couple of fish, save them if possible. Use time not spend on catching fish to build a net...have more fish. Rinse, repeat.

That's probably why early civilization develloped in valleys of river that flooded.

In the Nile and Euphrate/Tigre valleys, there was plenty of food but efforts were required for storage. And one that was done, there was plenty of idle time for parts of the year.

Hence pyramids and stuff. (and writing for book keeping of stored food)

From a practical standpoint, food tends to rot quickly in nutrient rich environments such as the tropical rain forest.

Why save the fish if it's going to rot?

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