Week 4

Minerals and Life

In the last weeks you discovered that stars are generators of elements heavier than Hydrogen and that all elements and the compounds they create have different densities. Now we will explore what all of the elements do when released to the Universe and exposed to the gravity, heat, and pressures that exist there. Specifically we will look at the diverse circumstances within the mantle and crust of Earth which act as generators for the production of diverse mineral compounds that life uses to gather the elements it needs. You will learn how this relates to the development and diversification of life and how that life in turn is responsible for continuing to increase the mineral riches of Earth that we benefit from and use today.

Day 1 - 3

Day 4

Day 5

Day 1 - 3

Review that as heat and pressure change (PhET Simulation) that atoms and molecules change their distance from each other and their speed. As the Earth's crust began to cool this allowed different atoms and molecules to slow and contact others combining and forming the minerals that compose the Earth's rocky surface.

The diversity environments in Earth's oceans, crust, and atmosphere created an opportunity for many new compounds and minerals to form in new environments where they make and break bonds to create a new abundance of minerals that was much greater than could be made in the cold, solid, vacuum of space.

All elements want to have a full outer shell; the Octet Rule. Molecules are broken and made when exposed to different levels of energy and environments. This allows the Earth to make a diversity of new materials in its surface and internal processes.

Play with this simulation and see how different atoms will bond until they become stable and how when molecules are broken and given the opportunity to bond with newly introduced atoms they will.

Evolution of minerals (optional reading). Note the complexity and variety of processes and environments within the Earth's crust below. Each gives rise to unique minerals with unique chemical and physical properties. More about the relationships between minerals and life can be found here (optional).

Earliest proposed life is Rybozymes according to the RNA World Hypothesis. These were a logical chemical evolutionary steps stemming from the mineral and environmental evolution of the planet due to cycling of molecules between the geosphere, hydrosphere, and atmosphere. The biosphere then plays a role in influencing them all.

Create the connection between the rocks and minerals that were formed during the creation of the Earth and life by watching Life's Rocky Start. This will lay the foundation for us to understand fossil fuel formation and climate change that compose the bulk of this semester.

You should be able to answer these questions:

How old is the Earth?
What do meteorites tell us?
What can a zircon crystal tell us?
What did the Miller-Urey experiment show?
What environment is the "pressure bomb" experiment simulating?
What helped RNA and other complex molecules form early in Earth’s history?
What are stromatolites responsible for?
What is the relationship between minerals and life?
How have life and minerals affected the climate?

Day 4

The origins of life can be hypothesized by using logic and examining ancient rocks and fossils on Earth. Zircons, stromatolites, ancient sea beds near Greenland, ancient beds of iron oxide in Australia, trilobites in the Antiatlas Mountains, meteorites in Morroco, and countless other finds are points of evidence for life's evolution on the planet from rocks and minerals to us.

Deep ocean vents have minerals, energy, and liquid water. They are an excellent place for the chemistry of life. Amino acids, fatty acids, a variety of minerals and more were able to consistently construct RNA, proteins, and fatty acid bilayers to create an area of inner and outer chemistry controlled by ribozymes. The ancestors of these early life forms are called cells and viruses.

RNA can be produced fairly easily in the environments of early Earth. It was likely produced continuously in the sediments of the ocean. RNA has properties that make it the most likely candidate for the first life and as the precursor to DNA, cells, and viruses.