I have met northern chinese who always say that southern chinese look different from them and can distinguish them.

Single and double eyelid is just one of the criteria. You cannot deny that most southerners have more double eyelid than the northerners and southerners are usually shorter. There are other characteristics as well to distinguish but I have not met that many northerners especially in japan or mongolia to know the differences. Some northerners have migrated south resulting in some of the population having single eyelids.

Another characteristics is the skin is usually very pale for the tungusa and the sinica have light tan skin in most cases.

Some say that the tungusa are hairier than the sinica ? It may be true due to the adaption to the colder weather. Some say that the tungusa are taller and larger than the sinica. Basically, it is just like comparing the vikings (nordic caucasian) to the italians or spanish. Vikings are usually hairier and bigger build than the southern europeans.

Qin dynasty horsemen are not 100% replica of the real men up to single or double eyelid. Some double eyelid in sinica are very thin and so difficult to sculpt. Do you find moles or wrinkles on the hands and faces of these replicas ?

Style is also one thing affecting look. If you never cut your hair, well, you will not look like persons around you, even the same "sub-ethnicity". I can somehow distinguish mainlanders from HKers apart from language. When I ask a HKer how to distinguish between HKers and mainlander (mostly BJer?), he said style is quite different.
Many Northerners also have double eyelid. But since my consciousness about eyelids are quite "recent", I have not noticed any meaningful thing. And do you mean that many Northerners don't know the difference? Perhaps.
Once I asked a Northerner how to distinguish by look, and he said "no, language first".
I notice that the single/double eyelid of Chinese mostly is an illusion of different strength of epicanthic fold (not the same as eyelid fold). You can see from (the link to) the picture I posted. http://www.chinahistoryforum.com/index.php...dpost&p=4768533
0: perfect double eyelid. This is kind of eyelid seem "more normal" since they fold in "normal" way (the eyelid "fold outside").
1: distorted double eyelid, you see that the eyelid is less symmetric than level 0. Why? Epicanthic fold are enclosing some part of eye, but not too strong so that you can see the eyelid fold is still not enclosed by it. You notice an extra "slant" after the "end" of eye.
2: single eyelid, the eyelid fold is now enclosed by the epicanthic fold and the eye start to seem sunk in.
3: single-lidded, seemingly-sunk eyes.
Many Chinese have almost-single eyelids (still look "double").
I also found that some persons have single eyelid in one side, double in other side, but the double is "weak" (you say "thin"). I mean almost covered.
And don't you know the legend of Southward migration of Cantonese, Hokkien and Hakka?

Once I heard someone said Shanghainese are the palest, even can be as pale as or even paler than Beijingers, so no clue toward it. It's not one criteria for me.

Arctic environment is extreme.. I see that most Arctic Asian are very fat. Mongolian are taller? I've never directly compare them with Chinese, I can't tell anything but I think North China and Mongolia are still not Arctic.
With the same Northerner person as above, I saw one of his friend, a short mainland girl, and I asked whether she was from Beijing or not. And the answer is yes. And I said that I thought Beijingers were taller than Southerners. And he said: 'Northerners are bigger than Southerners; Mongolians are bigger than Chinese, and Beijingers are taller than Southerners; she is an exception.' And I said 'I think it is probably affected by lifestyle; I see some tall HK girls; And it seems that they have been long in overseas..'

I thought that the girls' height is quite distinctive, tall girls are usually from North, short girls (shorter than me) are usually from South. I don't say about boys since most boys here are tall and not very different from BJers.

After some observation, I found that the average is not much different from me. BJ girls are probably only slightly taller than me. (I may have seen the wrong people, but anyway language first ).
And (local, not overseas I think) HK girls are also not that short. Many are clearly shorter than me but the average seem about the same height as me.
As to self-prove whether I am wrong or not, I have to go to mainland and compare...

Also you once said that newer generations of Malaysia's Chinese are tall.. I don't see if gene are very much responsible for that, so after a few decades you will not be able to distinguish from height.

I don't think the Japanese are too closely related to the Tungusic peoples. For one thing, as mentioned Japanese people often have high bridged noses. But the nose bridge of Tungusca is extremely flat, as images on this thread have shown.

Maybe I have not been clear in my past posts.

The original han chinese were of sinica mongoloid since they originated from the yellow river (or if you go even a few thousand years earlier - from the kunlun mountain). The temperature in the yellow river is not as extremely cold as the altaic mountain or mongolia.

Northern chinese
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But no tribes are completely isolated in not having intermarriages or migration if they border each other.
Thus, since the chinese who stayed behind in the northern region of china borders the tungusic people like mongolians, manchurians etc , some (but not all) did acquire some tungusic feature such as single eyelid etc.

the beijing girl that you met may originally be of pure sinica genes (because her ancestors were not involved in any gene mixing and they didn't migrate south like the cantonese, hakka, min) but height alone doesn't determine the branch, you have to look at the other factors that I mentioned earlier.


Southern chinese
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The early chinese who migrated southwards during the han, tang dynasty(cantonese, min etc) due to population expansion etc were not mixed with the tungusic genes yet. Instead they mixed with another sinica genes (such as the zhuang, yue etc) when they intermarry with the locals after migration.

Any migration which occur after the gene mixing occur will give more tungusic feature to a person. If you see a southerner with tungusic feature, it may be because these are recent migrants (such as one generation) from the north due to better economic opportunities in the south. I am sure you can migrate freely between south and north china since they are the same country.

Summary
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You can say that there are more people with tungusic feature in northern china (but not all).
And more people with sinica feature in southern china (but not all).
How many percentage ? Nobody knows.

I think that australoids are a mix between the 3 main groups . The dravidians are certainly not caucasoids as they are usually of smaller build (similarly to the mongoloids), but their dark skin color and very curly hair eg. the negritos (resembles the negroids), but their skulls, eyes, nose are closer to the caucasoid. It is just my observation and may not be correct.

I don't see many image of "Tungusa" here. There could be many high-nose-bridge "Tungusic" individuals... Just I want to see whether many Japanese also have flat nose.

Short or tall is affected quite much by lifestyle. You witnessed it yourself in your country.

Actually I don't agree with the single eyelid->Tungusa, double eyelid->Sinica. I split into 4 categories (just because of this picture below).
http://yuwenyan.home.bj001.net/xfile.php?x...eye2+12.17c.JPG
Looking from Qin Yong and Han Yong, "weak" double eyelid (~1, may not look double eyelid from far away.) and "weak" Single eyelid (~2, will not look sunk-in) was natural-lookings of Chinese.
Perhaps I'll call "Hun" and "Yue" instead. (who are "Sinica"? mix of both group? ).
I once saw a comment make from Northern Chinese saying that they don't look Mongolian and vice versa, so seems that they are "Yue" enough.

I don't know how the Australoids are, but from my observation seemingly they are closer genetically to Asians, could be an evolution of mix Africans-Asians in the tropical area. The Australoid also have pseudo-Caucasian effect.
Caucasoids probably are also mix African-Asian with very different percentage and evolved in cold area.

What a laugh. I have to agree with you that these examples are very atypical.

I've never seen a southern Chinese, or northern Chinese, that looks like the so-called "sudsinid" shown here. He looks Korean to me. The "mitellsinid and "nordsinid" don't look very Chinese either. This is what a real northern Chinese looks like...