Beginning of Life

Early Earth= not a friendly place Atmosphere was mostly methane, nitrogren, water vapor, and ammonia… nearly no oxygen Atmosphere was mostly methane, nitrogren, water vapor, and ammonia… nearly no oxygen The earth was very hot with many volcanoes exploding at once The earth was very hot with many volcanoes exploding at once Many thunder and lightning storms Many thunder and lightning storms

Alexander Oparin Believed that life began in the oceans. Believed that life began in the oceans. He believed that sun and lightening made organic molecules form. He believed that sun and lightening made organic molecules form. Rain then washed these molecules into the oceans and made a primordial soup. Rain then washed these molecules into the oceans and made a primordial soup.

Oparin’s hypothesis Rain + earth’s heat + lightning + CO 2 = life’s first lipid membrane in a shape of a sphere Rain + earth’s heat + lightning + CO 2 = life’s first lipid membrane in a shape of a sphere The small sphere of lipid membrane is called a protocell. The small sphere of lipid membrane is called a protocell. These were located in the ocean and were the very first beginnings of life. These were located in the ocean and were the very first beginnings of life.

Was he right? Miller & Urey tested Oparin’s hypothesis Miller & Urey tested Oparin’s hypothesis Water vapor, ammonia, methane, Hydrogen Add electricity Cool mixture to produce liquid Collect & analyze

The Miller-Urey Experiment Organic molecules appear here

After one week… They found: They found: Carbohydrates, amino Acids, and other small ORGANIC (living) molecules Carbohydrates, amino Acids, and other small ORGANIC (living) molecules Small protocells Small protocells This evidence supported Oparin’s hypothesis. This evidence supported Oparin’s hypothesis.

Prokaryotes evolved to become eukaryotes by endosymbiosis: Big cells swallow little cells that perform specific functions Prokaryote ingests aerobic bacteria Aerobic bacteria produces energy inside prokaryote  Prokaryote ingests cyanobacteria Cyanobacteria contains photosynthetic pigments  Mitochondria chloroplasts

The very first cells were autotrophs They made their energy from the sun. Because they were doing photosynthesis, they were releasing oxygen into the atmosphere. This allowed more complicated life to evolve.

Two other possible theories of where life began Hydrothermal vents Space!

Spontaneous Generation Believed that simple living organisms could come into being by spontaneous generation. Believed that simple living organisms could come into being by spontaneous generation. non-living objects can give rise to living organisms. non-living objects can give rise to living organisms. It was common “knowledge” that simple organisms like worms, beetles, frogs, and salamanders could come from dust, mud, etc., and food left out, quickly “swarmed” with life. It was common “knowledge” that simple organisms like worms, beetles, frogs, and salamanders could come from dust, mud, etc., and food left out, quickly “swarmed” with life.

Terms to Know Prefix for without? A- Word for beginning?Genesis Prefix for life? Bio- Biogenesis=beginning with life Life beginning from a non living thing Abiogenesis Spontaneous generation = abiogenesis

Virgil-Roman Poet Some believed that bees could form if you left meat under your house for 23 days

Jan Baptista van Helmont- physician in 1600s Others believed that if you left dirty clothes out for 7 days rats would form

Early Thoughts? Spontaneous Generation- the idea nonliving material can produce life Spontaneous Generation- the idea nonliving material can produce life Francesco Redi Francesco Redi Disproved the idea that decaying meat produced maggots (immature flies) Disproved the idea that decaying meat produced maggots (immature flies) Disproved the spontaneous Disproved the spontaneous generation of large generation of largeorganisms.

The first true experiment? Open Jars Closed Jars Francesco Redi -1600s Italian scientist Did this show that life did not come from non-life? Even with different types of meat closed jars=no maggots Disproves spontaneous generation

Vital Source Scientists thought that there must be a vital source in the air that makes microscopic organisms grow. Scientists thought that there must be a vital source in the air that makes microscopic organisms grow. In the mid 1800’s Louis Pasteur designed an experiment that disproved the spontaneous generation of microorganisms. In the mid 1800’s Louis Pasteur designed an experiment that disproved the spontaneous generation of microorganisms. In his experiment air, but not microorganisms could touch the broth. In his experiment air, but not microorganisms could touch the broth.

Louis Pasteur French Scientist, who in 1859 finally disproved spontaneous generation French Scientist, who in 1859 finally disproved spontaneous generation

Pasteur’s Experiment

Biogenesis This experiment led to the idea that: This experiment led to the idea that: Living organisms come only from other organisms. Living organisms come only from other organisms. But how did life START on Earth? But how did life START on Earth? How does life come from non-life 4.6 billion years ago? How does life come from non-life 4.6 billion years ago?

Molecules of the Atmosphere Carbon Dioxide Hydrogen Cyanide (HCN)

Create your own Primordial Soup Cans Include: 1.Ingredients 2.How to make it

 An early theory of evolution was proposed by Jean Lamarck  Lamarck proposed organisms acquired traits during their lifetime and passed them on to their offspring. This is known as Lamarckism.  What is wrong with this theory?

Lamarck’s Theory Individuals can evolve to adapt to changing conditions (acquired traits) Individuals can evolve to adapt to changing conditions (acquired traits)

Darwin’s Theory Traits that help in survival are passed on to offspring Traits that help in survival are passed on to offspring Traits that do not help in survival are lost from the gene pool Traits that do not help in survival are lost from the gene pool

Darwin’s Theory of Natural Selection 1. There is variation in individuals. 2. Living things over- reproduce. 3.There is a struggle to survive. 4.Those that survive are the most fit.

Who was Charles Darwin? Who was Charles Darwin? Who was Charles Darwin? Who was Charles Darwin? How Does How Does How Does How Does Evolution Really Work? Evolution Really Work? Evolution Really Work? Evolution Really Work? How do we know Evolution Happens? nZUIDQ How do we know Evolution Happens? nZUIDQ nZUIDQ nZUIDQ

Why does evolution matter now? Why does evolution matter now? Why does evolution matter now? Why does evolution matter now? WumllRPLI WumllRPLI WumllRPLI WumllRPLI