The Eagle Nebula A nursery in space This is the raw materials that stars are made of. The big bang you’ve all heard about was a huge “explosion” that distributed matter and energy throughout our universe, about 15 billion years ago. Our sun and solar system being born some 4.6 billion years ago. As seen through Hubble Telescope We are made of stardust!

How life originated on Earth has fascinated and intrigued humanity for as long as we have had the capacity to think on a higher level. Many answers have been proposed, but still the mystery remains. Let’s review some of the most common of these beliefs, and inferences. Black smokers deep within the Atlantic Ocean near the mid- ocean ridge. The Mid-Ocean Ridge is the longest mountain chain on the Earth. It is an area where the Earth’s crust is expanding.

The oxygen in the atmosphere today comes mainly from plants and microorganisms such as algae. (Cyanobacteria) oxygen given off, CO 2 taken up More organisms photosynthesizing…more O 2 in our atmosphere from reducing to oxidizing to ozone… Earth's atmosphere was a reducing one, chock full of methane, ammonia, hydrogen and water vapor. The first forms of life were prokaryotic in nature, and by necessity, they were anaerobic. These early methanogens (methane-producers) used the available elements (hydrogen, helium, sulfur…etc) in a sort of “chemosynthesis” process, creating simple carbohydrates in much the same way our photosynthesizing organisms do today.

If liquid water had not accumulated, membranes which take on their bilayer organization only in the presence of water could not have formed. No membrane, no cell. Life at its most basic level is the cell, which has the capacity to survive and reproduce on its own. = phosphate = lipid

In the presence of this “reducing” atmosphere, energy from the sun, volcanoes, and lightning caused chemical reactions among these gases, which eventually combined into small organic molecules such as amino acids. Rain trapped these atmospheric molecules and carried them to the oceans, making a primordial soup of organic molecules. Once in this “soup” the proteins, lipids, and complex organic molecules found in present-day cells, formed.

Next, diversification occurs (aka adaptive radiation or divergent evolution). Some cells developed that became metabolically capable of photosynthesis. This caused a cascade of irreversible events, (called the G.O.E.) interconnected by biogeochemical cycles. It is important to realize that the first organisms on Earth could not have relied on the Sun’s energy (photosynthesis), or an oxygen-rich atmosphere, which is precisely why we study the hydrothermal vent community along the Mid-Oceanic Ridge.

In the 1950s the great scientific race to solve the puzzle of life’s origins was on. While they didn’t create life, so to speak, they did provide evidence to support the “primordial soup” theory in that they produced organic molecules out of the mixture. The Miller-Urey experiment featured an apparatus into which was placed a reducing gas atmosphere thought to exist on the early Earth. The mix was heated up and given an electrical charge and simple organic molecules were formed. Amino acids (building blocks of proteins)

Other experiments were successful at producing glucose, ribose, deoxyribose, and other sugars What are the organic molecules that must have been present for early life to begin? amino acids: to form proteins sugars (which are a part of nucleotides) A nucleotide is three things: a nitrogenous base; a sugar; and a phosphate group. Fatty acids (lipids)

Some scientists think that the formation of self-replicating molecules such as DNA and RNA came before living cells. RNA probably predates DNA on Earth. RNA is more complex than the protein it codes for, and it is not as complex as DNA, scientists think it must have predated DNA. DNA is far more efficient at packing in more coding information for the production of proteins, and it is quite a bit more sophisticated than RNA.

Spontaneous formation of lipids, carbohydrates, amino acids, proteins, and nucleotides under abiotic conditions Formation of protein- RNA systems, and DNA evolution Protein Synthesis and self-replication became possible through transcription of DNA and translation of RNA Formation of lipid spheres Membrane-bound proto-cells First true-living cells The first cellular life

One scientific hypothesis about the origin of life on Earth is that the molecules necessary for life arrived here on meteorites, rocks from space that collide with Earth’s surface. Many meteorites contain organic matter. These organic molecules, which are necessary for the formation of cells, might have arrived on Earth and entered its oceans. Scientists today have used meteorites to help determine the original Earth’s atmosphere. meteorites contain atmospheric gases trapped in shock melted minerals

This theory proposes that cellular organelles originated as bacterial cells that developed a symbiotic relationship with other cells. (host-anaerobe / symbiont-aerobe) So, mitochondria originated as a bacterium Ribosomes originated as a bacterium We find accidental partnerships in nature all the time. Some species spend their entire lifetime inside the host species. The early aerobic prokaryotes which were ingested, resisted digestion in their “host”, and thrived. Buchnera aphidicola are obligate endosymbionts of aphids E. Coli are endosymbionts within human intestines

Life as we don’t know it The discovery of bacteria that use a different chemical building block in its structure stretches the scientific definition of "life." So what???

Even though doubt has been cast upon the experiment that led to the arsenic-based life discovery in Lake Mono, scientists are searching for other evidence on Earth to find “critters” that are and have been here, and we just haven’t noticed them because we are so focused on life that is similar to us. Perhaps life has been present on Earth for far longer than we expect. What might life based upon silicon look like?

Can a person “believe” in scientific theories? The answer can only be, “No.” The fact that the Earth is very old and life has changed over billions of years is scientifically valid”, because that is what the evidence tells us. Science is not about belief (based on faith)—it is about making inferences based on evidence. A person may, however, believe in Divine Origins, as is the case with 95% of human cultural groups on the planet. Religion is faith based, whereas science seeks universal truths based on experimental findings, that have been tested and tested over and over again. This is not necessary in religion, because of “FAITH”. Problems do occur when one tries to use “religion” to explain scientific phenomena, or use “science” to explain religious phenomena. (ie, intelligent design) Let’s look at several creation stories, and determine the difference between “belief, and inference”.

Common to all human cultures throughout history is the belief that life on Earth did not arise spontaneously, but through divine intervention. All creation stories have themes in common. A birth Mother/Father images A supreme being A supreme place, either above or below