What is the Relationship between behavior and survival? What is the Relationship between behavior and survival? How did this dictate the diversity of organisms? How did this dictate the diversity of organisms? Do these diverse organisms have anything in common with me? Do these diverse organisms have anything in common with me?

What was the early Earth like and how did life come about? What was the early Earth like and how did life come about?

Some theories Divine Creation: Life on Earth was put here by some divine force commonly thought of as God or gods. Divine Creation: Life on Earth was put here by some divine force commonly thought of as God or gods. Big Bang: The beginning of the universe began with an explosion that sent energy and matter in all directions. (1927 Belgian Priest Georges Lemaître) Big Bang: The beginning of the universe began with an explosion that sent energy and matter in all directions. (1927 Belgian Priest Georges Lemaître) Extraterrestrial Origins: Life came from someplace outside of Earth, such as a fallen meteorite or asteroid. Extraterrestrial Origins: Life came from someplace outside of Earth, such as a fallen meteorite or asteroid.

Spontaneous Origin: Life came from a number of chemical reactions starting from nonliving matter or chemicals Spontaneous Origin: Life came from a number of chemical reactions starting from nonliving matter or chemicals Origin of Life Chemical Reactions Simple Organic Molecules Chemical Reactions Self-replicating molecules Nonliving Matter Living Organisms

Early Earth Q: Could we have survived in the Early Earth? A: NO!! Very harsh conditions

Primitive Atmosphere Composed of hydrogen (H 2 ), nitrogen (N 2 ), carbon dioxide (CO 2 ), water vapor (H 2 O) and carbon monoxide (CO) Maybe even some ammonia (NH 3 ) and methane (CH 4 ) Oxygen (O 2 ), is not present in a free form!!

Harsh Conditions Anaerobic = no O 2 Interior of the Earth was very hot = many active volcanoes High amounts of the sun’s UV light covered the Earth = harmful to DNA Intense lightning

Heterotroph Hypothesis An explanation to the Spontaneous Origin Hypothesis An explanation to the Spontaneous Origin Hypothesis Several steps or ideas that help this theory come about Several steps or ideas that help this theory come about –Nonliving chemicals transferred into organic macromolecules –Genetic, replicating material comes about –Cellular organization –Cells and life come about

Non-living Chemicals to Organic Molecules First hypothesized by Russian Scientist A.I. Operin. First hypothesized by Russian Scientist A.I. Operin. Energy from volcano eruptions, lightning and solar radiation allowed for chemical reactions and formation of new organic macromolecules Energy from volcano eruptions, lightning and solar radiation allowed for chemical reactions and formation of new organic macromolecules Miller-Urey experiment helped Miller-Urey experiment helped show that this was possible. show that this was possible.

N 2 and H 2 gasses were introduced to electrical sparks (lightning). This caused e- to jump, forming organic molecules such as amino acids, and fatty acids.

Genetic Information “RNA world” “RNA world” –Can form spontaneously –Can replicate itself Catalyzed the formation of protein synthesis Catalyzed the formation of protein synthesis

Cellular Organization Small cellular looking formations called microspheres Small cellular looking formations called microspheres –Made from the joining of organic molecules –Have selectively permeable membranes –Store and release energy Q: What specific characteristics do today’s cells have that can link them to microspheres? A: bi-layer membrane, mitochondria, ATP

First Cells Heterotrophic: got their energy from outside sources Heterotrophic: got their energy from outside sources –Photosynthesis came much later Prokaryotes Prokaryotes –Single celled, no nucleus –Included some organelles later found in eukaryotes (mitochondria and chloroplasts) –Endosymbiont Theory: These organelles were engulfed by larger prokaryotes eventually becoming eukaryotes.

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