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September 15, 2004

Size matters

As I've stated before sometimes it is good to have numbers and be precise about what you mean in absolute numerical terms rather than just implying ordinal rankings. So, I found this page which gives you the sexual dimorphism (male:female size ratio) for the apes:

 male:female

Orang2
Gorilla1.5
Chimp1.3
Bonobo1.2
Human1.1
Gibbon1.02

A higher ratio implies a more polygynous mating system and sexual selection on males by females. FYI, this page gives a result of 1.27 (based on CDC numbers), and it states that 10% of American males are lighter than the average American female. This site offers 1.95 for gorillas and 1.25 for humans.

Another table:

male:female

Gorilla 2.36
Orangutan 2.21
Bonobo 1.36
Chimpanzee 1.2
Siamang 1.09
Gibbon 1.07

Well, there goes my idea of moving past ordinality toward more precision...but, readers might find this page interesting, "Between-population variation in pre-adolescent growth." The author states:
...The range of means for 28 Europeans and European-origin populations is 119.1 to 126.5 cm, similar to those for African and African-origin populations (119.6 to 126.0 cm), and Indo-Mediterranean populations (120.2 to 126.0 cm), but higher than that for Asiatic populations (118.1 to 122.6 cm). This supports Martorell's (1988) suggestion that genetic potential for growth is similar for all groups examined in this way, apart from Asiatic populations.

Readers might be curious to know that in 1975 Phyllis Eveleth & James Tanner published an article in Annals of Human Biology titled Differences between ethnic groups in sex dimorphism of height, and they concluded that Amerindians displayed the greatest amount of dimorphism, while Africans and Papuans the least. Their book, Worldwide Variation in Human Growth, seems to be a compilation of much of their research.

Update: Here is a list of heights from 1958 over at the Racial Reality blog.

Posted by razib at 10:25 PM