Topic:• The Introduction of Biology• Defining of life• Classification of living things• Ecosystem and human interferences• Basic chemistry, the chemistry of organic molecules

• Darwin evolutions• History of cells • Cells structures and functions • Photosynthesis and cellular respirations

• The early embryonic stages of a (a) lemur, (b) pig, and (c) human show strikingly similar anatomical features.

Evolution

• Change is species over time

• Organisms alive today descended from older organisms

• Evidence is overwhelming

• All living things share a common ancestor.

• We can draw a Tree of Life to show how every species is related.

• Evolution is the process by which one species gives rise to another and the Tree of Life grows

The Tree of Life

Evolution as Theory and Fact

Rodin’s “The Thinker”

• Confusion sometimes arises as to whether Evolution is a theory or a fact. Actually it is both!

• The theory of Evolution deals with how Evolution happens. Our understanding of this process is always changing.

• Evolution is also a fact as there is a huge amount of indisputable evidence for its occurrence.

Evolution….Evolution…..Evolution….Evolution…..• The processes that have transformed life on earth

from it’s earliest forms to the vast diversity that characterizes it today.

• A change in the genes!!

Old Theories of EvolutionOld Theories of Evolution• Jean Baptiste LamarckJean Baptiste Lamarck (early 1800’s) proposed:

““The inheritance of acquired characteristics”The inheritance of acquired characteristics”

• He proposed that by using or not using its body parts, an individual tends to developdevelop certain characteristicscharacteristics, which it passespasses on to its offspringoffspring.

““The Inheritance of Acquired The Inheritance of Acquired Characteristics”Characteristics”

• Example:Example:

A giraffe acquired its long neck because its ancestor stretched higher and higher into the trees to reach leaves, and that the animal’s increasingly lengthened neck was passed on to its offspring.

Darwin's general theory presumes the development of life from non-life and stresses a purely naturalistic (undirected) "descent with modification"

• published in 1859, Darwin proposed how one species might give rise to another.

• This would lead to the natural selection of the best adapted individuals and eventually the evolution of a new species.