We are searching data for your request:
Prenatal hormone levels determine human finger length
The finger length is determined by the prenatal hormone level. For some years now, researchers have been assuming that there is a direct connection between the hormone level before birth and the later length of the fingers, since both factors are determined by the same gene sequence. Now US scientists from the University of Florida at Gainesville have first clearly scientifically proven that finger length is influenced by prenatal hormone levels.
Estrogen and testosterone determine finger length As Martin Cohn and Zhengui Zheng from the University of Florida report in the journal "Proceedings of the National Academy of Sciences" (PNAS), the difference in the length ratio between the ring and index fingers in men and women can be demonstrated by the proportion female and male hormones during embryonic development. Depending on the estrogen or testosterone content, this leads to either a longer ring finger as an index finger in men or a longer index finger as a ring finger in women, the US researchers explained. As part of a comprehensive study, the University of Florida scientists examined the effect of prenatal hormone levels on the "finger length" in mice. The results allow conclusions to be drawn about the interplay between finger length and hormone levels in humans, since the mice have a human-like finger length ratio, the US researchers explained.
In their investigations, the US scientists discovered a particularly high density of receptors for the sex hormones testosterone and estrogen in the budding fingers of the mouse embryos. When the testosterone receptors were blocked, the mice developed a typical female finger length ratio, report Martin Cohn and Zhengui Zheng. The same effect was shown with the additional administration of estrogen. When testosterone was added, the mouse embryos, on the other hand, showed the typical male finger length ratio of a longer ring finger than an index finger, according to the US researchers. This is the first clear proof that prenatal hormone levels determine finger length, the experts from the University of Florida explained.
Prenatal hormone levels crucial for individual properties? Although there has been no scientific evidence to date regarding the relationship between prenatal hormone levels and finger length, previous studies have already used finger length as an indicator of hormone levels. Based on this indicator, the studies then associated the hormone level with certain properties such as behavior, technical or social interest, sexual orientation and the expression of the male genitalia. The individual risk of disease for autism, breast cancer, depression and heart diseases has also been linked to prenatal hormone levels in the course of the studies. Even sexual attraction and professional success later in life were linked to finger length and prenatal hormone levels. However, most of these examinations showed clear deficiencies and were accordingly not taken into consideration by the medical community. One of the points of criticism was always the extrapolation of the prenatal hormone level based on the finger length. However, since the current study by the US researchers now provides clear evidence of the effects of prenatal hormone levels on finger length, the previous criticism seems to be unjustified, at least on this point. (fp)
Career choice predetermined by hormones
Wandering thoughts make you unhappy
Menopause also affects men
Breast cancer screening: a lot of exercise instead of hormones
Breast cancer through hormone treatments
Image: Kora Polster / pixelio.de