Telegony (pregnancy)

Telegony is a theory in heredity, holding that offspring can inherit the characteristics of a previous mate of the female parent; thus the child of a widowed or remarried woman might partake of traits of a previous husband. Experiments on several species failed to provide any evidence that offspring would inherit any character from their mother's previous mates.[1] A similar phenomenon, whereby environmental (non-genetic) traits were passed, was later discovered in a species of fly.

Etymology

The term was coined by August Weismann from the Greek words τῆλε (tèle) meaning 'far' and γονος (gonos) meaning 'offspring'.[2] The name may also refer to Odysseus' son Telegonus; the lost poem named after him is Telegony.

Early perceptions

The idea of telegony goes back to Aristotle. It states that individuals can inherit traits not only from their fathers, but also from other males previously known to their mothers.[3] in other words, fatherhood is not indivisible: paternity can be partitioned.

The theory, expounded as natural history by Aristotle, was accepted throughout Antiquity. The concept of telegonic impregnation was expressed in Greek mythology in the origins of their heroes. Such double fatherhood, one immortal, one mortal, was a familiar feature of heroes such as Theseus, who was doubly conceived in the same night. By the understanding of sex in Antiquity, the mix of semen gave Theseus a combination of divine as well as mortal characteristics. Of a supposed Parnassos, founder of Delphi, Pausanias[4] observes, "Like the other heroes, as they are called, he had two fathers; one they say was the god Poseidon, the human father being Cleopompus." Sometimes the result could be twins such as Castor and Pollux, one born divine and one mortal.

The more general doctrine of "maternal impressions" was also known in Ancient Israel. The book of Genesis describes Jacob inducing goats and sheep in Laban's herds to bear striped and spotted young by placing dark wooden rods with white stripes in their watering troughs.[5] Telegony influenced early Christianity as well. The Gnostic followers of Valentinius (circa 100-160 CE) characteristically took the concept from the physiological world into the realm of psychology and spirituality by extending the supposed influence even to the thoughts of the woman. In the Gospel of Philip, a text among those found at Nag Hammadi:

Whomever the woman loves, to him those who are born are like; if her husband, they are like her husband; if an adulterer, they are like the adulterer. Often when a woman sleeps with her husband, but while her heart is with the adulterer with whom she is accustomed to unite, she bears the one whom she bears so that he is like the adulterer."[6]

The concept of telegony was revived with the rediscovery of Aristotle in the Middle Ages. This was part of the resistance to the marriage in 1361 of Edward, the Black Prince, heir to the throne of Edward III of England, with Joan, the Fair Maid of Kent, who had been previously married: their progeny, it was thought, might not be completely of his Plantagenet blood.

Understandings in the 19th century and the collapse of the theory in the 20th

In the 19th century, the most widely credited example was that of Lord Morton’s mare, reported by the distinguished surgeon Sir Everard Home, and cited by Charles Darwin.[7] Lord Morton bred a white mare with a wild quagga stallion,[8] and when he later bred the same mare with a white stallion, the offspring strangely had stripes in the legs, like the quagga.[9]

Surgeon-General of New York, Professor Austin Flint, in his Text-Book of Human Physiology (fourth edition, 1888) described the phenomenon as follows:[10]

Text-Book of Human Physiology (fourth edition, 1888) , page 797
"A peculiar and, it seems to me, an inexplicable fact is, that previous pregnancies have an influence upon offspring. This is well known to breeders of animals. If pure-blooded mares or bitches have been once covered by an inferior male, in subsequent fecondations the young are likely to partake of the character of the first male, even if they be afterwards bred with males of unimpeachable pedigree. What the mechanism of the influence of the first conception is, it is impossible to say; but the fact is incontestable. The same influence is observed in the human subject. A woman may have, by a second husband, children who resemble a former husband, and this is particularly well marked in certain instances by the colour of the hair and eyes. A white woman who has had children by a negro may subsequently bear children to a white man, these children presenting some of the unmistakable peculiarities of the negro race."

Austin Flint, Professor of Physiology, Cornell University Medical College

Both Schopenhauer and Herbert Spencer found telegony to be a credible theory;[11] August Weismann, on the other hand, had expressed doubts about the theory earlier and it fell out of scientific favor in the 1890s. A series of experiments by James Cossar Ewart in Scotland and other researchers in Germany and Brazil failed to find any evidence of the phenomenon. Also, the statistician Karl Pearson pointed out that, if telegony was true, later children of the same couple should increasingly resemble their father, which is not the case.[12]

Biologists now explain the phenomenon of Lord Morton's mare with reference to the dominant and recessive variants of a gene: both the mare and the stallion had a recessive gene; the foal inherited these alleles and thus displayed the characteristic invisible in its parents.

In mammals, each sperm has the haploid set of chromosomes and each egg has another haploid set. During the process of fertilization a zygote with the diploid set is produced. This set will be inherited by every somatic cell of a mammal, with exactly half the genetic material coming from the producer of the sperm (the father) and another half from the producer of the egg (the mother). Thus, the myth of telegony is fundamentally incompatible with our knowledge of genetics and the reproductive process. Encyclopædia Britannica stated "All these beliefs, from inheritance of acquired traits to telegony, must now be classed as superstitions."[3]

Recent developments

A group from the University of New South Wales[13] has demonstrated the occurrence of a seemingly telegonic phenomenon in a species of fly.[14] These results were initially presented at the 2013 XIV Congress of the European Society for Evolutionary Biology[15][16] and the Australasian Evolution Society’s conference.[17]

Like father like son? Nongenetic paternal effects reinvigorate the possibility of telegony
"As a first step towards disentangling whether the effect is borne by the sperm itself or by accessory-gland products (ACPs) in the seminal fluid, we mated females initially to a male in high or low condition and then remated the female to a new male in high or low condition two weeks later. Interestingly, offspring size and viability were determined by the condition of the first male, with no effect of the condition of the second mate. Genetic tests confirm this result holds even when the second male is the biological father of the offspring. These findings suggest the paternal effect is mediated by ACPs, and provide a compelling case for reassessing the possibility of telegony as a valid phenomenon."

Crean A.J., Kopps A.M., Bonduriansky R., University of New South Wales

In addition, a Chinese scientist has proposed possible molecular mechanisms that may account for telegony; however, his work is predicated on the beliefs of pre-Mendelian breeders to reinforce the idea that traits are passed from earlier matings.[18][19] The proposed mechanisms include the penetration of spermatozoa into the somatic tissues of the female genital tract, the incorporation of the DNA released by spermatozoa into maternal somatic cells, the presence of fetal DNA in maternal blood, incorporation of exogenous DNA into somatic cells, presence of fetal cells and fetal DNA in maternal blood and sperm RNA-mediated non-Mendelian inheritance of epigenetic changes.

As reported in 2014, experiments with the fly Telostylinus angusticollis showed that "it is possible for a male to transmit features of his phenotype via non-genetic semen-borne factors to his mate's subsequent offspring sired by another male."[20]

Influence in culture

Telegony influenced late 19th-century racialist discourse: a woman who had once had a child with a non-Aryan man, it was argued, could never have a "pure" Aryan child again. This idea was adopted by the Nazis.[11]

Telegony re-emerged within post-Soviet Russian Orthodoxy. Virginity and Telegony: The Orthodox church and modern science of genetic inversions was published in 2004. Pravda.ru gave an overview of the concept and a brief review of the book, saying that the authors invented "scary and incredible stories" to "make women be very careful about their sexual contacts" and that the idea was being used by the Church to scare the faithful.[21] Anna Kuznetsova, who was appointed Children's Rights Commissioner for the Russian Federation in 2016, had said several years earlier that she believes in the concept, amongst other fringe views. The founding editor of the business newspaper Vedomosti[22] interpreted the appointment of someone with such views as a sign that Russian President Vladimir Putin was becoming more ideological.[23]

See also

Notes

  1. ↑ Burkhardt, RW (1979). "Closing the door on Lord Morton's mare: the rise and fall of telegony". Studies in History of Biology. 3: 1–21. PMID 11610983.
  2. ↑ Bynum, Bill (April 2002). "Telegony". The Lancet. 359 (9313): 1256. doi:10.1016/S0140-6736(02)08200-4.
  3. 1 2 http://www.britannica.com/EBchecked/topic/262934/heredity
  4. ↑ Pausanias, Description of Greece x.6.1.
  5. ↑ "Telegony". The Encyclopædia Britannica. 26. 1911.
  6. ↑ Gospel of Philip, p112. Noted in Robert M. Grant, "The Mystery of Marriage in the Gospel of Philip" Vigiliae Christianae 15.3 (September 1961:129-140) p. 135.
  7. ↑ Darwin, Variation of Animals and Plants Under Domestication (1868).
  8. ↑ The quagga was a relative of the zebra, now extinct.
  9. ↑ "Lord Morton's Mare"
  10. ↑ Flint, Austin (1888). Text-Book of Human Physiology (fourth ed.). USA: Appleton,New York. p. 797.
  11. 1 2 Jan Bondeson, A Cabinet of Medical Curiosities, 1999:159.
  12. ↑ Pearson, K. (1 October 1909). "Statistics of telegony". Science. 30 (770): 443–444. PMID 17777275. doi:10.1126/science.30.770.443-a.
  13. ↑ "Evolutionary Biology Lab People". Retrieved 28 December 2013.
  14. ↑ Crean, A. J.; Kopps, A. M.; Bonduriansky, R. (2014), "Revisiting telegony: offspring inherit an acquired characteristic of their mother’s previous mate", Ecology Letters, 17: 1545–1552, PMC 4282758 Freely accessible, PMID 25270393, doi:10.1111/ele.12373.
  15. ↑ "Like father like son? Nongenetic paternal effects reinvigorate the possibility of telegony". XIV Congress of the European Society for Evolutionary Biology. Retrieved 28 December 2013.
  16. ↑ Nakagawa, Shinichi. "ESEB conference in Lisbon". Otago University. Retrieved 28 December 2013.
  17. ↑ "Mia, Frank, Woody and Darwin". Deakin University. Retrieved 28 December 2013.
  18. ↑ Liu, YS (April 2011). "Telegony, the sire effect and non-Mendelian inheritance mediated by spermatozoa: a historical overview and modern mechanistic speculations". Reprod Domest Anim. 46 (2): 338–43. PMID 20626678. doi:10.1111/j.1439-0531.2010.01672.x.
  19. ↑ Liu, Y (July 2013). "Fetal genes in mother's blood: A novel mechanism for telegony?". Gene. 524 (2): 414–6. PMID 23618818. doi:10.1016/j.gene.2013.03.061.
  20. ↑ Crean, AJ; Kopps, AM; Bonduriansky, R. "Revisiting telegony: offspring inherit an acquired characteristic of their mother's previous mate". Ecol Lett. 17: 1545–52. PMC 4282758 Freely accessible. PMID 25270393. doi:10.1111/ele.12373.
  21. ↑ "Woman's first partner may become genetic father of all her kids, telegony says". Pravda Report. 27 June 2007. Retrieved 8 November 2016.
  22. ↑ "LEONID BERSHIDSKY". Bloomberg. Retrieved 8 November 2016.
  23. ↑ BERSHIDSKY, LEONID (12 September 2016). "Putin Promotes the Next Generation of Ideological Cronies". Bloomberg View. Retrieved 8 November 2016.

References

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.