The history of Life and earth. Early Ideas. Will rotting give rise to maggots ? Can mud produce live fish? Will a bag of wheat give birth to mice?. Spontaneous Generation . the idea that non-living material can produce life. Francesco Redi (1668). an Italian physician
Over time, maggots filled the open jars but not the covered ones.
This showed that only flies produce flies.
Although Redi disproved the spontaneous generation of large organisms, many scientists still believed that microorganisms must arise spontaneously
They believed there must be some vital force in the air that caused microorganisms to arise
living things can only come from other living things
- prokaryotes that live in harsh environments like hot springs
- do not require oxygen
This theory explains the origin of chloroplasts and mitochondria.
Three properties of chloroplasts and mitochondria shared with prokaryotes: circular DNA, similar ribosomes, reproduced by fission.
Which is an example of the theory of
Tadpoles become frogs.
A starfish can grow from a severed arm.
Damp hay and corn create mice.
From a tiny acorn, an oak can grow.
Why do scientists believe that archea are
the closest relatives to Earth’s first cells?
They are eukaryotes.
They contain DNA.
They carry out photosynthesis.
They live in extreme environments.
Who is the scientist who showed that microscopic life is not produced by spontaneous generation?
He estimated the Earth to be
millions of years old. He wrote the "Theory of the
The human population was growing faster than the space and food needed to provide for it. Natural disasters and forces of nature would solve the problem
“If the earth can change over time, then why can’t the things on it?”
What is a Theory? – well-supported testable explanation of phenomena that have occurred in the natural world
1859 Darwin published his book:
On the Origin of Species
“Life changes over time by the process of natural selection.”