What’s in an Egg?
Unscrambling the mysteries
Imagine a container filled with amorphous-looking bits of metal, plastic and some software chips. Could you imagine it breaking out as a fully-assembled scale model motor car? Then growing larger as it absorbs raw materials, as well as energy, from its surroundings? What sort of advanced software engineering would be required? As for any ideas of it being able to ‘marry’ another like itself, thus repeating the whole cycle by producing another container of metal, plastic and software … such notions could rightly be dismissed as ludicrously far-fetched, even in our technologically advanced age. Yet in the world around us, similar things are happening all the time in those shell-wrapped marvels-in-miniature called eggs.
From egg to chicken
Chicken eggs are laid only about 25 hours after ovulation (i.e. release of the egg from the hen’s ovary). Breaking open the shell of a freshly-laid fertilized egg would reveal a tiny (2 mm, or 1/12 inch, in diameter) white mass of cells—the blastodisc—on top of the yolk.1 If an intact egg is kept warm under a broody hen or in an incubator, the chick will develop from these blastodisc cells, with body folds of the embryo beginning to separate from the underlying yolk.
John P. Giesy, Michigan State University
Birds not hatching from over-fragile egg shells first alerted the world to certain industrial pollutants. Man-made chemicals were also responsible for the mutation-caused deformity in this cormorant.
Crucial to embryo development is the formation of various membranes (partitions) including the yolk sac, amnion and allantois. The amnion encloses the embryo inside a fluid-filled cavity which not only buffers the embryo against short-term external temperature extremes but also cushions it if the egg is bumped. With the embryo closed off from the outside world by the shell,2 there is the problem of how to dispose of excretory wastes. Here is where the allantois is so crucial, as it serves as the embryo’s garbage bag. (When the chick hatches, the accumulated wastes can be found sticking to the inside of the abandoned shell.)
While these membranes are forming, the embryo itself continues to develop, differentiating the various organ systems. Four days after an egg is laid, the heart is visible and large blood vessels can be seen to have grown out from the embryo into the yolk sac. By eight days the eyes, darkly pigmented, are prominent. On the 11th day the brain is visible through the transparent skull, the limbs are obviously developing, and feathers appear by the 14th day. By 21 days (i.e. just before hatching), the ‘egg tooth’ is visible—the knob on the end of the beak which the chick uses to break out of the shell.
- Eggs have long been hand-coloured and exchanged, apparently as part of the pre-Christian ‘rites of spring’.1 It is easy to see how the egg would be regarded as symbolic of the renewal of life after a long cold winter. In many cultures, the egg represented fertility and was a sacred symbol to the Babylonians.
- As Christianity spread, the egg was adopted by many as a symbol of Christ’s Resurrection. People in central European countries have a long tradition of making elaborately decorated Easter eggs. The Russian royal family carried this tradition to great lengths, as can be seen from the ornate jewelled eggs made by goldsmith Carl Fabergé from the 1880s until 1917.
- The Extraordinary Egg, <fairfield. osu.edu/fcs/openhearthapr23.html>, 25 February 2002.
Ready, set, grow!
Newly hatched chicks weighing around 40 g (1.4 oz) are now ready to find food for themselves. In favourable conditions they can grow extremely rapidly, attaining weights of 2.6 kg (5.7 lb) in around six weeks.3
All the instructions for a chicken this size were present in the original tiny blastodisc inside the egg. Could the egg, its contents of such intricate construction, wrapped in a seamless protective shell and programmed to grow, possibly have originated by evolutionary ‘chance and necessity’? The improbability of an egg, outside the context of a Creator God, simply defies reason (Romans 1:20).
Which came first? The chicken or the egg?
Evolutionists would reason as follows. A chicken comes only from a chicken egg. But in the past, they say, there must have been something almost like a chicken (but not quite) which gave rise to the first chicken, by mutation (random genetic copying mistakes). Given Mendel’s laws of inheritance, the transition from non-chicken to chicken can only take place between the egg-layer and the egg. Thus, they say, the egg came first.1,2
Let’s ignore here that their whole scheme relies on the belief that massive amounts of new information have to be added to convert a primordial fish into a chicken (no mutation has ever been observed that adds information to the DNA—just the opposite).3 What does the Bible say concerning the age-old question about the chicken and the egg?
According to Genesis 1, God created all the animals and birds, each ‘after their own kind’, and then instructed that they were to be fruitful, and multiply, and increase on the Earth.
So God designed and made the ‘chicken kind’ (male and female), and later, the very first ‘chicken egg’ was laid. To the extent that that first chicken population differed from today’s chickens, it would have been genetically richer, capable of giving rise to a wide variety within that particular kind. But the bottom line is that it was the chicken that came first, before its egg.
- The egg came before the chicken, <www.nyu.edu/gsas/dept/philo/faculty/sorensen/papers/egg.html>, 18 February 2002.
- Which came first, the chicken or the egg?, <www.howstuffworks. com/question85.htm>, 18 February 2002.
- Spetner, L., Not by chance!, The Judaica Press Inc., New York, pp. 138, 159–160, 1997.
What is an ‘egg’?
In biology, the term ‘egg’ most often refers to the female sex cell, or gamete, across a multitude of species, from rabbits to redwood trees, camels to corn plants.
However, ‘egg’ can also be used to describe the entire specialized structure or capsule that consists of the ovum, its various protective membranes, and any accompanying nutritive materials. Thus, for most people, an egg is a hard-shelled reproductive body (normally regarded as food) that is produced by a bird or reptile.
But it’s not just bird or turtle eggs that are considered as food. Fish eggs (‘roe’) are eagerly consumed by many around the world. In Russia, caviar—the salted eggs of sturgeonfish—is a prized delicacy.1
All birds, and some reptiles and fish, are oviparous—their eggs continue to develop after being laid, and hatch later. Some reptiles (e.g. Garter Snakes) and fish (e.g. guppies) are ovoviviparous—i.e. they have shelled eggs that hatch as they are laid, making it look like ‘live birth’. However (unlike the situation in viviparous organisms giving birth to live young—e.g. sheep), after ovulation, the mother’s body supplies no nutrients—only oxygen—to the developing embryo, which thus develops on the energy in the yolk.
- Encyclopedia Britannica, 15th Ed., 2:976, 4:386, 1992.
- If you hard-boil freshly-laid (still warm) eggs, the shell will stick to the white,
making it hard to peel. But as the egg mass shrinks from water loss after a few
days in the dry air of a refrigerator, the membrane separates from the hard shell,
allowing easy peeling.
Eggs harden when boiled due to the heat first breaking (unfolding) the proteins, which then allows these to form new, stronger bonds with other proteins. As these stronger cross-links form, the protein chains are prevented from sliding past each other, leaving the egg hard. Mechanical whisking of egg whites also breaks protein bonds, and again, new, stronger bonds subsequently form, so the material will never return to its original consistency.
- Blood spots in the egg are the result of rupture of one or more small blood vessels in the yolk at the time of ovulation.
- Double/triple yolks result when two/three ova are released from the ovary at the same time or when progress of the previous day’s ovum through the oviduct is slowed and the newer ovum catches up.
- Variation in internal colour is due to many factors. If very fresh, the egg white (albumen) will be cloudy, while a clear egg white is an indication the egg is aging. Pink or iridescent egg white indicates bacterial spoilage. The yellow shading of the yolk varies according to the hen’s diet—lighter on a colourless diet (e.g. white cornmeal) and dark yellow if she eats plenty of yellow-orange plant pigments called carotenoids (e.g. marigold petals and yellow corn). A green surface on the yolk is the result of overcooking, caused by sulfur compounds in the white reacting with iron compounds in the yolk.
- The colour of the eggshell depends largely on the breed of chicken. Chickens with white feathers, such as the Leghorn, White Rock and Cornish, lay white eggs. Dark-feathered (red-black) chickens such as the Rhode Island Red, New Hampshire and Plymouth Rock lay brown eggs. Araucuna chickens in South America lay eggs with shells ranging from medium blue to medium green.1
- The egg is laid blunt end first.
- Quail eggs have been successfully hatched in space (on the Russian Mir spacecraft in 1990 and 1992).2
- The extinct giant elephant bird (Aepyornis maximus) of Madagascar laid
eggs 39 cm (15.4 in) long with a volume of 12 litres (2.26 gal). Of living birds,
the ostrich egg is the largest, being up to 20 cm (8 in) long and weighing up to
1.76 kg (3.87 lb)—equivalent in volume to 24 chicken eggs. The smallest known
bird’s egg was a Vervain Hummingbird (Mellisuga minima) egg less than 9.9
mm (39/100 in) long, and weighing just 0.365 g (0.0128 oz).3,4
The largest dinosaur egg ever recovered (in China) was 46 cm (18 in) long.5,6
References and notes
- The Extraordinary Egg, <fairfield.osu.edu/fcs/openhearthapr23.html>, 25 February 2002.
- Incubator-Integrated Quail Experiments on Mir, <spaceflight.nasa.gov/history/shuttle-mir/science/fb/sc-fb-quail.htm>, 26 February 2002.
- Bird facts, <www.obelus.com/birds/facts.html>, 26 February 2002.
- The Amazing World of Birds, <www.earthlife.net/birds/intro.html>, 27 February 2002.
- Dinosaur eggs, <www.nationalgeographic.com/dinorama/eggs.html>, 27 February 2002.
- The animal pairs that God brought to Noah to put aboard the Ark would most likely
have been juveniles (perhaps timed to reach maturity at the end of the Flood—ready
to repopulate the Earth).
The relatively small size of dinosaur eggs shows that juveniles of even the largest dinosaur species were small enough to be easily accommodated in the Ark’s huge volume. See Grigg, R., Thunder lizards, Creation 22(4):14–17, 2000.
References and notes
- Information in this section is drawn from Curtis, H., Biology, 4th Ed., Worth Publishers, New York, pp. 859–864, 1983. Return to text.
- The shell stops the egg drying out but is porous enough to allow oxygen to filter in to the developing chick. It also protects the egg from most bacteria. A crack in the eggshell a few days after laying is usually fatal, as it allows bacteria to penetrate. A crack will also cause excessive moisture loss. Return to text.
- Agri Facts: Poultry and Egg Industry, <nfpc-cnpa.gc.ca/english/factpoultryeggstructure. html>, 26 February 2002. Return to text.
(Also available in Greek)
I raised chickens for a number of years and what I found interesting is the baby and the shell had an understanding. As the baby gets close to coming out the shell changes from so the chicks can peck though. Another observation is the chick had a dance as it made its way around the shell. I made the mistake of helping the chick as I thought it was in distress only to have a deformed chick on my hands. If the baby did not go through a "s" shape dance the head and back did not form, and the feet would be deformed as well. I did manage to save several of these chicks but they were always a nuisance to care for. I only took care of the because I made the mistake. Just like human babies coming down the channel to be birth the chick does the same thing. I call it a dance. I learned that the chick needs the struggle in order to come out ready to meet the needs of the world. It is like us humans, we need the struggles of life in order to make us strong and efficient. So often we do to much, and we make misfits. It is in the trials of life we grow.
Actually, I thought you would have touched on the “chicken or the egg first?” question by referencing this finding announced in 2010 (although I haven’t searched your archives so you may have commented on this finding when it was announced): the chicken had to have come first because the protein that builds the egg shell is found only in adult chickens’ ovaries: [web link deleted as per feedback rules]
Thanks for this fascinating information. I think the reason that this 2002 article failed to include this 2010 information was that the author inexcusably lacks time travel ability ;)
Actually, our policy is to try to publish one article per week from our Creation magazine archives, and this means selecting articles that are still “fresh”. We think Dr Catchpoole’s article provides fascinating information, and most importantly, none to our knowledge has been superseded by more recent discoveries. Compare also the 1993 article The mind of God and the ‘big bang’ which we could republish in 2010 with only the most minor editorial changes because so little needed updating.
Our readers certainly deserve to benefit from your discovery, so here goes:
British scientists claim to have solved the mystery
msnbc.msn.com, 14 July 2010
It is an age-old riddle that has perplexed generations: Which came first, the chicken or the egg?
Now British scientists claim to have finally come up with the definitive answer: The chicken.
The scientific and philosophical mystery was purportedly unraveled by researchers at Sheffield and Warwick universities, according to the Daily Mail newspaper.
The scientists found that a protein found only in a chicken's ovaries is necessary for the formation of the egg, according to the paper Wednesday. The egg can therefore only exist if it has been created inside a chicken.
The protein speeds up the development of the hard shell, which is essential in protecting the delicate yolk and fluids while the chick grows inside the egg, the report said.
“It had long been suspected that the egg came first but now we have the scientific proof that shows that in fact the chicken came first,” said Dr. Colin Freeman, from Sheffield University’s Department of Engineering Materials, according to the Mail.
“The protein had been identified before and it was linked to egg formation, but by examining it closely we have been able to see how it controls the process,” he said.
Evolutionary belief DRIVES evolutionists, and drives them hard, against the clear weight of the bare facts, - that an extremely sophisticated and orderly system is created, over being randomly splurged. Now for all the creative sophistry they would apply in telling me I am wrong about that, at the end of the day, it still comes down to a random splurge versus immense wisdom and unsearchable knowledge.
Now think - to write a book containing great wisdom and unsearchable knowledge, which is the best answer for what written that book? Someone with great wisdom and knowledge to match what the book contains OR, a random burst of ink splurged for no reason?
Just as a blind, legless dog would be inferior as a goal-scorer, to a footballer, an all-wise mind is superior in thinking than a thoughtless, blind, inadequate, naturalistic and unproven mechanism.
I think the sophistication of the evolution theory scares those with weak, conforming-faith. But that sophistication exists not because evolution is true, but because they have to reason away the truth, and to do that, you need a very clever and complete theory, that seemingly is impossible to refute. You then stick to that theory even upon pain of death, in your level of stubbornness, as well as your agreeing peers, and *bang* - there you have it, the duped oblivious masses.
If only man would search his heart.
Question … I have had recent thoughts that those advocating abortion are biologically wrong when they claim that the embryo is part of the woman’s body. It seems that from what I've read many years ago, any transmission of blood from the mother to the embryo would kill the embryo as the the mother's system would see the baby as a foreign invader and develop antibodies to kill it. The fertilized egg must first develop defensive mechanisms to fool the host, the mother. Please pardon my ignorance, but is the baby really part of the mother's body or just an egg shell? Have you already addressed this somewhere that I could read?
Indeed, we have an article on that very topic: Abortion argument unravels—How the unborn child defends itself against its mother, confirming that he/she is a separate human being from the start.
Also, here is an argument against the baby being part of the mother's body, to illustrate the technique of logical argumentation called reductio ad absurdum.
In 2010, we published an article, Unborn babies may “be planning their future”: What now for the abortion lobby? This discussed a New Scientist article that stated:
Could a fetus lying in the womb be planning its future? The question comes from the discovery that brain areas thought to be involved in introspection and other aspects of consciousness are fully formed in newborn babies.
It is amazing what a fertilised egg has to grow into its own kind! All the DNA information to construct its infancy to its adult body using only relevant materials including nerve system, brain, heart, blood vessels, hearing, seeing, digestive system and reproductive system is encoded in the materials of an egg.
If only Darwin knew the amazing complexity in DNA information, would he have still believed in natural selection and mutation leading to molecules-to-moral-human evolution?