Fluctuating asymmetry
Encyclopedia
Fluctuating asymmetry is an organism’s deviation from bilateral symmetry. It can be measured in the body—as in bilateral symmetry of finger lengths—or in a particular organ. It is related to concepts of symmetry such as facial symmetry
, and is believed to measure the ability of the genome
to successfully canalize
and buffer development
to achieve a normal phenotype under imperfect environmental conditions, as implied by Waddington's
notion of canalization. As such it is a key concept in evolution and development, and underlies concepts such as resilience or developmental stability—the ability to maintain a normal developmental course under stress.
In individual differences research, FA has been associated with human traits such as social dominance, working memory, and intelligence. In old age, facial symmetry has been associated with better cognitive aging. There is some evidence that the degree of bodily symmetry in individuals influences our assessment of how well they dance, supporting Darwin's suggestion that dance is a sexually selected courtship signal.
Symmetry also affects physical attractiveness
.
Facial symmetry
Facial symmetry, is one element of bodily symmetry, including fluctuating asymmetry. Along with traits such as averageness and youthfulness it influences judgements of aesthetic traits of physical attractiveness and beauty, and is associated with fitness-linked traits including health, It is also...
, and is believed to measure the ability of the genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
to successfully canalize
Canalisation (genetics)
Canalisation is a measure of the ability of a population to produce the same phenotype regardless of variability of its environment or genotype. In other words, it means robustness. The term canalisation was coined by C. H. Waddington...
and buffer development
Developmental biology
Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...
to achieve a normal phenotype under imperfect environmental conditions, as implied by Waddington's
Conrad Hal Waddington
Conrad Hal Waddington CBE FRS FRSE was a developmental biologist, paleontologist, geneticist, embryologist and philosopher who laid the foundations for systems biology...
notion of canalization. As such it is a key concept in evolution and development, and underlies concepts such as resilience or developmental stability—the ability to maintain a normal developmental course under stress.
In individual differences research, FA has been associated with human traits such as social dominance, working memory, and intelligence. In old age, facial symmetry has been associated with better cognitive aging. There is some evidence that the degree of bodily symmetry in individuals influences our assessment of how well they dance, supporting Darwin's suggestion that dance is a sexually selected courtship signal.
Symmetry also affects physical attractiveness
Physical attractiveness
Physical attractiveness refers to a person's physical traits which are perceived to be aesthetically pleasing or beautiful. The term often implies sexual attractiveness or desirability, but can also be distinct from the two; for example, humans may regard the young as attractive for various...
.