Frogs and Snails – Sugar and Spice

Remember the nursery rhyme:

What are little boys made of?
Frogs and snails
And puppy-dogs’ tails,
That’s what little boys are made of.

What are little girls made of?
Sugar and spice
And everything nice,
That’s what little girls are made of.

In reality we and everything else including frogs, snails, sugar and spice are made, in the words of Carl Sagan, of “Star Stuff”. Our sun is a star that generates heat by a process called fusion, converting about 3.6×1038 protons (hydrogen nuclei) into helium nuclei every second. Some further fusion then takes place to form the elements heaver than helium. But for a star the size of our sun the heaviest atom that can be formed is iron (Fe) with an atomic number of 26. The periodic table has elements all the up to 118. Our bodies contain elements heaver than iron. Where did they all come from?

The age of the universe is estimated as 13.7 + 0.13 billion years since the Big Bang. Our solar system was formed from the collapse of a giant molecular cloud only about 4.6 billion years ago. That cloud came from a supernova, an explosion great enough to create all the elements heaver than oxygen including those heaver than iron. These elements then enriched the molecular cloud which over time condensed to form our solar system which, of course, includes earth.

Life first formed on earth about 3.8 billion years ago and has progressed along the following approximate basic timeline (Source: Wikipedia).

• 3.8 billion years of simple cells (prokaryotes),
• 3 billion years of photosynthesis,
• 2 billion years of complex cells (eukaryotes),
• 1 billion years of multicellular life,
• 600 million years of simple animals,
• 570 million years of arthropods (ancestors of insects, arachnids and crustaceans),
• 550 million years of complex animals,
• 500 million years of fish and proto-amphibians,
• 475 million years of land plants,
• 400 million years of insects and seeds,
• 360 million years of amphibians,
• 300 million years of reptiles,
• 200 million years of mammals,
• 150 million years of birds,
• 130 million years of flowers,
• 65 million years since the non-avian dinosaurs died out,
• 2.5 million years since the appearance of the genus Homo,
• 200,000 years of anatomically modern humans,
• 25,000 years since the disappearance of Neanderthal traits from the fossil record.
• 13,000 years since the disappearance of Homo floresiensis from the fossil record.

All that was simply a build up to my recommending a book titled “The Disappearing Spoon” by Sam Kean. It’s basically a book about the history of the Periodic Table with one heck of a lot of additional information thrown in. It’s also funny. I’m not going to tell you where the title came from, you’ll have to read the book.