Riddles of sex, sex chromosomes and laterality

What is the evolutionary purpose of differentiation into female and male sex, right- and left hemispheres of the brain,

 “The “reversed” sexual size dimorphism of predatory birds, bats, rabbits, flying squirrels, spotted hyenas,

Sexual dimorphism in plants (there is no struggle for or choice by the female plant)?

The dependence of sexual dimorphism on the reproductive structure of the population.

Molecular biology

One of the three “sensations” of “Human genome” program: why most mutations are in the Y-chromosome?

Jumping genes: where and why do they jump?

Asymmetric Y ®Хcrossing-over?

Autosomal localization of “sex” genes: gametes, gonads and genitalia?

Why placenta (female organ) is controlled by male’s genes, while “common” embryo—by female’s genes?

Better selection properties for male sex in agricultural animals and plants?

Dominance of a father on divergent characters and of a mother on convergent ones?


Why embryo sucks the right thumb?

Bigger left side of an embryo?

Right hemisphere control of intrauterine development in humans.


Why do women have better verbal abilities?

— men have better visual-spatial abilities?

— women have better sense of smell?


Why do women usually live longer than men, but men are “champions” in the duration of life?

High birth- and death- rate of males and left-handed people under extreme conditions?

Excessive birth-rate of boys in during wars ("phenomenon of war years") and in harems?


Why some congenital anomalies are more frequently occur in boys while others—in girls?

— twice as much boys are born with one kidney, and 2.5-fold more girls—with three kidneys?

— congenital hip luxation is four times more frequent in girls, and the left side is the most frequently affected (60%)?

— patent ductus arteriosus, Lutembacher disease, and ostium secundum are more frequent in women?

— aortal stenosis, coarctation of aorta, and transpositions of the great arteries are more frequent in men?


Varicose strikes women more frequently and from the left side, and gout—males and from the right side?

All “new” diseases, diseases of civilization and urbanization (atherosclerosis, cancer, coronary

Men are more frequently damaged by immune deficit diseases (such as AIDS), while women—by autoimmune diseases (such as arthritis)?


Why men are more vulnerable to all social vices (alcohol, tobacco, drugs and gambling), but they damage women more severely?


Four types of male skulls and only one type of female skulls in Bashkir population.

Why dermatoglyphics of Bulgarian males is similar to Turkish type, while that of Bulgarian females—to Lithuanian type?


Why apes reach for and grasp food with the left hand, but manipulate (open bolts, turn nuts) with the right hand?

— siamangs, chimpanzees, orangutans, and gorillas prefer the right foot for beginning terrestrial movement?

— ovulation in dolphins occurs predominantly on the left ovary?

— only the left nostril of sperm whale is primarily associated with breathing?

— backs of penguin chicks blacken, and of beluga calves (Huso huso) brighten from the head?

— men have more asymmetric brain?

— there are 4-8 times more boys among the left handers, stutterers, cross-eyed, and dyslexics (deviations associated with brain asymmetry)?

— right-handedness and left footedness of

— handedness is correlated with sex (for each woman there is among the ambidextrous about 0.5 men,

— the left eye is more sensitive to simple signals (flash of light), and right eye—to complex ones (words, numbers)?

— the left ear is more sensitive to nature sounds, and right ear—to semantic ones?

— for dichotic vocal signals the right ear was preferred at first, after a week, the left ear?

— grasping reflex of newborns is stronger on the left?

— at ages from 6 to 12 years the right femur is larger, and after 13 — the left one?

— the heart is displaced to the left?