The Egg

By Dayli Romig-Leavitt

Eggs chickens lay them we eat them but eggs are so much more. In this blog we’re going to be talking about the history of the egg and some fun facts about the egg and it’s Shell.

The first eggs date back 385 million years ago. They were these little egg pods covered in jelly kind of like the eggs frogs lay today. Tetrapods were the first creatures to start wanting to be on dry land. But they had a problem. They needed to keep their embryos wet on dry land. The first species to possibly do so was Tessora; it lived during the carboniferous period around 334 million years ago. Some experts think this Tessora resembled a new group of creatures that wouldn’t appear until 20 million years later, the first true amniotes. An amniote is a mammal, reptile or bird whose embryo develops in an amnion and chorion and has an allantois. The amniotes laid a kind of egg that had never been seen before. It had a soft, leathery shell that protected the embryo from diseases and attacks. It was also permeable enough to let air in so that the embryo could still breathe. The egg had a lot of amniotic fluid inside that created a kind of pond so it stayed moist. The Tessora’s egg probably looked like an early form of the amniote egg.

With this kind of egg tetrapods didn’t have to stay in the swamp anymore so they could explore dryland, which was a good thing because of the carboniferous rainforest collapse. This collapse meant that parts of the planet started to dry up and many amphibian groups began to go extinct. But, the amniotes survived because they adapted better to dry climates with their shelled egg. The amniotes expanded into a variety of new niches.

But, wait! What happened between embryos in shells and embryos in jelly? No one knows and we call this period of missing egg information, the Egg Gap. Earliest records of any eggs we have is from the dinosaur, Patagonious, it lived 250 million years ago that’s about 100 million years after we think the first egg came to be. The reason for this gap is that there is no fossil evidence. Amniote eggs don’t fossilize well. The reason we know what we do is through observing and making inferences with closely related animals. This process is called phylogenetic bracketing. Since reptiles, mammals, and birds are all amniotes that means that the eggs must’ve come from the earliest common ancestor, the first true amnio.

The first unquestionable reptile was called the Palomas who lived 310 million years ago so the egg must be older than that. The story of the egg splits off around 215 million years ago into two groups. One was the Sauropsids, that would include birds, reptiles and dinosaurs and the other was the Synapsids, that are the ancestors of mammals. Now these two groups put their eggs in very different places.

The Sauropsids mostly laid eggs throughout their evolutionary life. The egg would change a little. Reptiles continued laying eggs like those of early amniotes like the turtle. While birds and their predecessors, the dinosaurs, laid eggs that started to have calcium in them. Calcium made the eggs harder and better for fossilization.

Synapsids took a much different path. Their early eggs also resembled eggs of early amniotes. Over 100 million years ago Synapsids started going from scaly reptile-like creatures to fully-furred animals with middle ear bones and were fully warm-blooded. They even developed mammary glands. When these early mammals were still laying eggs these mammary glands were first a source of water to keep eggs hydrated. They eventually became a source of milk for young after they hatched. All mammals produce milk, even the ones that lay eggs.This is where the manager is coming to the states they branched off around 106 million years ago this will be the last group of synapses to branch off that laid eggs and the monotremes of the past are probably a lot like the monotremes of today.

For example, the mother platypus keeps her eggs inside her body, fertilizing them before they hatch. Then she lays them and in less than two weeks they hatch. Experts think that they’ve been doing it more or less the same way this entire time.

But we don’t know the steps between laying eggs and having full on pregnancies because we don’t have much fossil evidence. There are a few options though, one of which is that like the platypus, we carried our young inside and then laid eggs in this way keeping the babies inside us for longer and longer periods of time. A change in the gene expression is another option. Because many of the elements that are inside eggs also are present in animals that give birth to live young. And yet a third option is that an ancient virus attacked one of our mammal ancestors but instead of using the materials to make more viruses we re-purposed it into a protein called syncytins that helps membranes fuse together and helps make the placenta which delivers food from the mother to the child. So those are the three ways that we could’ve developed into pregnancies. But, enough about the past, let’s talk about all the cool things you could do in the present day with some fun facts!

1: The pleats in chefs hats are traditionally equal to the number of ways they can cook an egg.

2: Producing hens don’t lay one egg at a time instead they lay several eggs in various stages of development.

3: It takes a hen between 24 and 26 hours for an egg to develop and then within 30 minutes the hen starts the development of another egg.

4: Egg day is June 3!

There are so many cool things you can do with eggshells alone (The following facts are just for the egg shells do not use the full egg in any of the following)

5: Eggshells are calcium and mineral rich so you can add them to wild bird and chicken feed.

6: and since they are calcium and mineral rich you can add them to your coffee before brewing to make it less bitter (wash thoroughly so there is no residue and crush up before adding)

7: Use it in your house plants to keep the soil loose and aerated.

8: use eggshells as a calcium substitute in juice and smoothies bake for 350° for eight minutes let cool and grind to a fine powder before adding

9: yeah another thing that picture of can do is act as an abrasive for pots and pans they are best when cleaning Products and hot water are at Large

10: eggshells are grounded up and put into protection spells and witchcraft Thank you for reading my blog, hopefully you found it informative and interesting! :)

NOTES: - Thank you to PBS Eons for the youtube video "How the Egg Came first" https://youtu.be/c_CCmae8Wrc This is where my report on the history of the egg came from. - Thank you Famers Almanac for the facts on eggs that I used in this post: https://www.farmersalmanac.com/15-june-3-egg-day-egg-facts-you-may-not-know

- THANK YOU GOOGLE!