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Post by Thoithoi O'Cottage on Feb 25, 2014 14:15:06 GMT 5.5
In the mid 2000s, reading some extreme feminist writings I came across the idea of females (they were talking about humans) capable (at will nor not—I did not know that) of producing children (only female, it seems now) without any male fertilizing them. Virgin birth. It was strange to me, but it could not intrigue me at that time. Today, reading “ Chinese Myths” by Anne Birrell, I come across the term “ parthenogenesis” ( παρθένος, parthenos, meaning "virgin" and γένεσις, genesis, meaning "birth)—of many Chinese goddesses and semi-divine female figures giving virgin births. (In the later Chinese tradition it is the male gods who give birth through a similar process, without a female agency, though I doubt its scientific possibility, not that myths are to be interpreted in a positivist way.) Quite intrigued this time, I did some quick reading earlier today. There were quite a few resources, and some of them were accessible to a biologically ignorant person like me. However, even after the little but scientific (I think, but am not sure, the sources are reliably scientific) the mystical air has not lifted and it continues to hang over this phenomenon. I’m not doing a research on this, but I’m just seriously curious to know more about this. While he is not always available, he has been so kind to spare some time every now and then to write on our forum, and reply to my queries. I mean kaka Dr. Lalit Pukhrambam. As you are the only person I can see among us, who can address this cloud in my mind, I earnestly (but being conscious of your time) ask you to write briefly (in non-technical English) to clear this uncertainty. |
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Post by Dr. Lalit Pukhrambam on Mar 1, 2014 23:42:27 GMT 5.5
Parthenogenesis or asexual reproduction is common in protozoans (single cell bacteria) and among the lower metazoans (multicellualr plants and animals) such as yeast, hydra, and in fishes and in some amphibians and reptiles. Asexual reproduction in mammals have not been observed so far. In asexual reproduction, the DNA in chromosome is divided by mitosis meaning that the same DNA is reproduced. So, the offspring has the same DNA as the mother or the father, there is no mixing of DNA from male and female counterparts. The advantage of asexual reproduction is that the organism can multiply quickly under suitable conditions when there is plenty of food available and the environment is right. In the sexual reproduction, the DNA from gametes (male and female counterpart germ cells) are mixed by meiosis (a process of cell division by mixing genetic material from male and female) and therefore the resultant offspring has a genetic variation from either parents. The advantage is that it is more adaptive to changes in the environment and so the natural selection when the environment is not constant.
One interesting example of interchange between asexual and sexual mode of reproduction by an animal is the reptiles. A reptile (for example a female Python) may choose to reproduce asexually with XX chromosomes. The offspring will be carbon copies of herself. Or it can also mate with a male python and produce either XX or XY sexually in the offsprings. It will not be same as herself because one X or Y will be from the male. In addition, there will exchange of genetic materials between chromosomes by meiosis (a process of cell division by sexual reproduction). Another interesting condition is with crocodiles, in which depending on the temperature of the eggs incubated, the offspring could turn out to be a male or a female offspring.
The concept of Parthenogenesis or virgin birth has been in the minds of many cultures especially when virginity became a virtue in many societies. Child birth without marriage or out of wedlock became tabooed and unacceptable socially, then to protect most likely the woman, a concept of virgin birth came to exist. It is still debatable among various civilizations/societies. The concept of evolution by Darwin is still argued against by religious groups including Churches in the US. Scientifically, why we need sexual reproduction? What triggers an unfertilized egg to become active to undergo division and grow when an oocyte (or ovum, the female germ cell) meets a sperm? The sperm does not contribute much material other than its DNA. These are some of the questions that scientists are still pondering.
In any case, I am not an expert in this topic as well but the concept of virgin birth among mammals including human beings is not scientifically accepted at present. Nonetheless, this religious belief still exists in virgin birth (e.g., that of Mary and Jesus) even though no one has encounter it.
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Post by Kunjo Naorem on Mar 3, 2014 14:26:01 GMT 5.5
It is very true. Parthenogenesis is now impossible in mammals but one day it may or may not possible artificially or due to Evolution. Nothing is sure about Future.
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Post by lena01 on Aug 31, 2017 12:54:40 GMT 5.5
Parthenogenesis is a natural form of asexual reproduction in which growth and development of embryos occur without fertilization. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component process of apomixis.
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