This is a book review of “Breeding between the lines: Why interracial people are healthier and more attractive,” by Alon Ziv, 184 pp., Barricade Books, 2006, ISBN: 1569803064.My preliminary impression that the book most likely doesn’t have decent data in it is confirmed.
For instance, in a national probability British sample of over 18,000 people, roughly 1% of people assessed reported that they were asexual, i.e., had no sexual interest in either men or women.
Similarly, whereas most people abhor incest, let alone indulge in it, some people continue to harbor incestuous fantasies and engage in incestuous sex[2-4].
There are numerous examples of evolutionary maladaptive characteristics that persist in small numbers in the population, but Ziv ignores this.
Ziv argues that our bodies are designed to have bilateral symmetry, i.e., we are designed to be perfectly symmetrical. There is both a random and a non-random component to bilateral asymmetry, and it is the random component that is not part of biological design.
Ziv acknowledges that races exist, but then cites pathetic sources to support this assertion: the approval of the drug Bi Dil for blacks by the FDA and a comment on Cavalli-Sforza’s book by Steve Sailer!
No serious scientist, aware of the nature of race denial, would cite such poor sources.
One needs to cite molecular[6-8] and skeletal evidence[9, 10] in conjunction with standard phylogeographic criteria for race assignment in order to make the case for races among humans.
The magnitude and direction (left or right side greater) of the random component fluctuates between individuals and hence this component is designated as fluctuating asymmetry.
Throughout the book, whenever Ziv cites the literature on symmetry and especially when he extols the virtue of greater bilateral symmetry as in corresponding to better health and greater attractiveness, he is actually referring to the literature on fluctuating asymmetry, and the correct statement is that a lower level of fluctuating asymmetry, rather than greater symmetry, is correlated with somewhat better health and greater attractiveness.
For instance, fluctuating asymmetry rather than directional asymmetry is a correlate of attractiveness of faces.
Ziv claims that heterozygosity for sickle cell anemia makes the carrier resistant to malaria, but this is not true; what happens is that the severity of malarial infection is reduced in these individuals, which increases the probability of survival should an infection occur.