Evolutionary Biology: Origin of Life

Evolutionary Biology

Life and its Origin

• Life on earth originated in water, and simple life forms changed over time to adapt to their surroundings
• Evolution is a slow, progressive, irreversible change that has resulted in complex plants and animals from simpler organisms over millions of years
• The term "evolution" refers to the process of continuous change, which applies to living organisms, planets, stars, and even the earth's topography

Theories of Origin of Life

• Various theories have been proposed to explain the origin of life on earth
• One of the theories is the Theory of Special Creation, which suggests that life was created by a divine being or superior power

Evolution

• Evolution can be defined as a slow and progressive change resulting in complexity from simple and lower organisms
• The doctrine of organic evolution states that present-day life forms with complex organization have arisen by gradual changes from simple forms that lived in the past
• Evolution is supported by various types of evidence, including anatomical, paleontological, embryological, morphological, and biochemical evidence

Theories of Evolution

• Iamarekisen, Darwinism, and Neo-Darwinism are different theories of evolution
• These theories propose different mechanisms for the evolution of life on earth, such as natural selection and genetic variation

Human Evolution

• The position of humans in the animal kingdom is closely related to other primates, such as monkeys and apes
• There are differences between new world monkeys and old world monkeys, as well as between apes and humans
• The evolution of modern humans began from anthropoid ancestors, and has involved a series of changes over millions of years

Biomolecules and Cell Biology

• Biomolecules are the basic and essential molecules of life, forming the building block and molecular basis of life.
• They vary in size from simple molecules like carbon dioxide and water to macromolecules like proteins.
• Biomolecules can be classified into two kinds: organic compounds and inorganic compounds.

Biomolecules Classification

• Organic compounds: Carbohydrates, Proteins, Fats, and Nucleic Acids.
• Inorganic compounds: Water, Minerals, and salts.

Carbohydrates

• Carbohydrates are essential biomolecules composed of carbon, hydrogen, and oxygen in the ratio of 2:1.
• The general formula of carbohydrates is $C_n(H_2O)_m$.
• Carbohydrates are also known as saccharides (Gr.saccharon = sugar).
• They are aldehyde and ketone derivatives of polyhydroxy alcohol.
• Carbohydrates can be classified into two types:
  • Aldoses: Containing an aldehyde group (-CHO) in the terminal position.
  • Ketoses: Containing a ketone group (=C=O) in the subterminal position.

Cellular Pool

• The collection of biomolecules in the cell is called the cellular pool.
• A cell possesses around 5000 types of chemicals, which carry out approximately 3000 types of reactions.

Explore the origin of life on earth, from simple forms in water to complex organisms over millions of years. Learn about the process of evolution and various theories of life's origin.