A woman has, within her ovaries, all the ova or eggs that she will ever have. No ova develop in a woman during her lifetime. When she ovulates one egg passes through her reproductive system and embeds itself in the wall of her uterus. If it is not fertilised, it gets shed with the lining of her womb during menstruation.
Actually, I skipped a point above. What a woman has in her ovaries are oocytes, or objects which have the potential to form ova. Even before oocytes form, the future baby girl has seven million oogonia, most of which die, some few hundred of which become oocytes.Embed from Getty Images
If you are wondering why I started thinking about ovulation and all that, the answer is chickens! Chickens lay eggs roughly every day once they start laying and lay for two to three years at least. Some lay for much longer.
I knew that ova, or rather oocytes, are not formed in human females once they are born, and I sort of thought that chickens would be similar. If my maths is correct, human females are born with five hundred or so oocytes, given that one ova is used up during each reproductive cycle and they have thirteen or so cycles per year for approximately forty years.Embed from Getty Images
Chickens however lay one egg per day, for up to four years or so, meaning that chicken ovaries have at least fourteen hundred to fifteen hundred oocytes, assuming a similar system to the human female system. Ah, Google showed me this article which pretty much confirms the above.
So, chickens are pretty much big bags of potential eggs. I found it interesting that chicken have an internal production line for eggs operating inside them, and several may be on their way to the outside world at any one time. When I read that it reminded me of my Gran, who used to pluck and gut her own chickens, showing me the immature eggs in a chicken’s oviduct. There can’t be many of the younger generations who have seen that!Embed from Getty Images
Of course a chicken egg must contain a life support system for the embryo (assuming the egg is fertilised, of course), whereas the life support system for mammals is contained within the mother’s body. This does allow humans to grow larger than chickens – the size of an external human egg would have to be at least as large as a small football, and probably larger, as the developing human embryo takes nourishment from the mother’s body, and an external egg would have to contain all that nourishment at the time that the egg is laid.
Another difference between chickens and humans is that the chicken’s offspring have to immediately be able to walk, eat, and largely look after themselves. The human offspring however can feed off the human mother’s milk for sometime, and can gradually get used to normal human foods, like pureed pears, laced with sugar in a glass jar. Yes, well, that’s a side track I can get into another time, I guess.Embed from Getty Images
In the animal group called the marsupials, this dependency on the mother is extreme. The babies (joeys) are so dependant on the mother’s milk and are born so small, that they are kept in the mother’s pouch until the become big enough for independent life.
So, which is the best strategy? Well, all things being equal a chicken could have at least a hundred or two offspring, but we aren’t drowning in chickens, so of the thousands of eggs that a chicken lays, only a small number don’t end up as scrambled eggs or feeding a predator. There is huge “wastage”.Embed from Getty Images
Humans on the other hand, well, we are drowning in humans, one might claim, so the strategy of having only a few, but initially very dependent offspring, seems to work for us as a species. In spite of the fact that children could be totally independent of their parents by the time they are reaching the end of their teens, most human children are so bonded to their parents that only the death of the parent breaks that bond.
Another advantage of laying eggs is that humans like eggs. Boiled, scrambled, fried, poached eggs. Eggs used in cooking. As result, rather than searching the landscape for eggs, humans have domesticated chickens. Everywhere humans are, there are chickens. They have even gone into space with us. On that measure chickens have been very successful. In exchange for a few unfertilised embryos chickens have gone further than chicken-kind has gone before. It’s even possible that when mankind sets up outposts on the Moon or Mars that chickens will accompany them.Embed from Getty Images
Of course, chickens are often kept in conditions which are, to put it mildly, not very nice. It’s even possible that at least partially because of this, that at some time in future, chickens as a food source may be phased out in favour of some sort of artificial egg production process. However, if we manage to visit and maybe colonise earth-like planets, we won’t initially be able to ship out vast protein manufacturing plants.
No, since we probably won’t know what we will find on a distant planet, we will probably ship along some chickens, or at least some eggs. In addition, if the chickens eat the local vegetation and then keel over, we will know that it is harmful, at least to chickens. In addition, the sound of clucking chickens is restful, and would remind the settlers of a distant of what they have left behind them. They would be a comfort, as well as providing a self replicating source of protein in several forms.Embed from Getty Images
In understand that scientists can produce chicken meat by using a chunk of chicken and feeding it with nutrients. They can then carve off chunks of it and feed it some more. I don’t know if they have actually tasted such meat, and what the pitfalls are for this scheme. There will be some. It’s likely that it is a cumbersome and tricky process.
No, I suggest that when we travel to the stars we take our chickens with us. Our motto could be “ad astra per alia pulli”. To the stars on the wings of chickens.Embed from Getty Images
[A note about Gettyimages. Gettyimages is a site that provides images, some of which are free and embeddable in WordPress, and no doubt other similar sites. I’ve decided to use images from Gettyimages to decorate my site. The images may or may not bear any relationship to my text, and I do not endorse any views represented or implicated by the images. They are just decoration. I highly recommend Gettyimages.]