"The Origin of Life on Earth" Evolution of Biology PPT Courseware 2

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"The Origin of Life on Earth" Evolution of Biology PPT Courseware 2

Was there life on the earth in the first place? What was the earliest life that appeared?...

We cannot observe it ourselves, and it is difficult to obtain direct evidence... Therefore, we can make scientific speculations about the origin of life through relevant research.

Scientific speculation requires conclusive evidence, strict logic, and rich association and imagination.

1. Several hypotheses about the origin of life

1.Creationism

2. Spontaneous generation theory

3. Theory of chemical origin

4. Yu Sheng said

5. Hot spring ecosystem

Origin of Life

1. Characteristics of the 4.6 billion-year-old primitive Earth:

It was blazing, with the red sun scorching in the sky, lightning and thunder, and volcanoes erupting on the ground, with lava overflowing. All elements are in a gaseous state and there is no life...

2. The primitive earth provided:

(1) Place: primitive atmosphere and primitive ocean

(2) Substances: methane (CH4), ammonia (NH3), water (H2O), hydrogen (H2), hydrogen sulfide (H2S), hydrogen cyanide (HCN), etc.

(3) Energy: cosmic rays, ultraviolet rays, lightning, energy released by volcanic eruptions, etc.

When did the origin of life occur?

Astronomers estimate that the Earth formed about 4.6 billion years ago.

The earliest fossils found so far record prokaryotes from 3.5 billion years ago.

The origin of life occurred approximately 4.5-3.5 billion years ago.

discuss

1. What is the difference between the composition of the earth's original atmosphere and the composition of the current atmosphere?

The original atmospheric composition had no oxygen. The current atmosphere consists of O2.

2. Was there life on the primitive earth? Give reasons.

does not exist. Because there is no environment in which life can exist.

3. Based on the results of Miller's experiment, speculation on the origin of life:

The primitive earth can produce organic matter that constitutes living organisms. Therefore, the stage of the origin of life from inorganic matter to organic matter is complete and achievable.

4. Meteorites contain organic matter needed to form living organisms. It can be inferred that:

The organic matter that makes up living organisms can be formed from outside the Earth and brought to Earth.

practise

1. Do you think that under the current environmental conditions, primitive life will no longer be formed on the earth? Why?

No more primitive life will form. Because there are no environmental conditions required for the formation of primitive life, such as primitive atmosphere, high temperature, continuous thunder and lightning, etc. In addition, the composition of the ocean is now changing.

2. Laozi, a famous thinker in ancient my country, said:

"Everything in the world is born from existence, and existence is born from nothingness." Does this coincide with the views on the origin of life in modern biology, or is it completely different? Give your opinion.

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For more information about the PPT courseware "Evolution of Biology and the Origin of Life on Earth", please click the Evolution of Biology ppt and the Origin of Life on Earth ppt tag.

"The Origin of Life on Earth" Evolution of Biology PPT Courseware 6:

"The Origin of Life on Earth" PPT courseware on the evolution of living things 6 Please think about how long it took for the earth to come into existence? Was there life after the creation of the earth? Approximately how long ago did humans come into being? How did it come about? What were the earliest organisms on earth like?

"The Origin of Life on Earth" Evolution of Biology PPT Courseware 5:

"The Origin of Life on Earth" Biological Evolution PPT Courseware 5 Exploration Read several hypotheses about the origin of life and talk about which view you agree with more. View 1: Creationism This view holds that life was created by God or gods. Viewpoint 2: It happens naturally..

"The Origin of Life on Earth" Evolution of Biology PPT Courseware 4:

"The Origin of Life on Earth" Evolution of Biology PPT Courseware 4 The earth was born 4.6 billion years ago. Was there life on the earth at first? What were the earliest creatures? 1. Several hypotheses about the origin of life 1. Creationism 2. Spontaneity 3. Cosmonogenesis 4. Chemical evolution..

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Update Time: 2024-10-07

This template belongs to biology courseware People's Education Edition Biology for Grade 8, Volume 2 industry PPT template

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