Theory of Evolution

By Morgan

Anatomical Evidence

Anatomical Vestiges

Example 1

In Whales and other Cetaceans, one can find small vestigial leg bones deeply buried within the back of the body. These are remnants of their land-living ancestors' legs

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Example 2

The wings of Ostriches, Emus, and other flightless birds are vestigial; they are remnants of their flying ancestors' wings.

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Example 3

Humans also bear some vestigial behaviors and reflexes. The formation of in humans goose bumps under stress is a vestigial reflex its function in human ancestors was to raise the body's hair, making the ancestor appear larger and scaring off predators.

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Biochemical Evidence

Molecular homology

DNA

Example 1

The deepest level of homology: The molecules that carry the instructions for making and running our bodies, encoded in our DNA.

The evolutionary history of a species can be seen in its DNA sequences. The more closely related two species are, the more similar their DNA sequences.

The very existence in of DNA every living thing on earth is, in itself, strong evidence of common ancestry. It would be highly unlikely for DNA to have evolved independently so many times, over and over.

We can see common ancestry in the chromosomes, themselves:

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Amino Acids

Example 2

Molecular homologies also can be seen at the level of the finished protein product encoded by the DNA, as shown in this comparison of amino acid sequence in hemoglobin of different species:
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Gel Electrophoresis

Example 3

The proteins of human and chimpanzee are about 99% identical. Does this show common descent through evolution? The building materials in a small brick home and the Empire State building may also be over 90% homologous; what does this mean?

There are at least 26 species of the protozoan Tetrahymena, all of which are nearly identical in structure, BUT there are enormous differences between their homologous proteins. The same is true of the more than 2000 species of fruit flies.

Comparing selected proteins, evolutionists hope to show not only phylogenetic relationships but also a "molecular clock" that will provide a relative time table for evolution. For example:

alpha chain of hemoglobin differs between horse and man by about 20 amino acids. Evolutionists believe that the horse and man "diverged" about 100 million years ago THEREFORE, the evolutionary rate of hemoglobin is ONE amino acid per 5 MILLION years. This rate is then extrapolated to other differences and in this way a "phylogenetic tree" is established complete with DATES!

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Paleontological Evidence

Fossil Record

Example 1

In the 17th century, Nicholas Steno shook the world of science, noting the similarity between shark teeth and the rocks commonly known as "tongue stones". This was our first understanding that fossils were a record of past life
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Example 2

Mary Ann Mantell picked up a tooth, which her husband Gideon thought to be of a large iguana, but it turned out to be the tooth of a dinosaur, Iguanodon. This discovery sent the powerful message that many fossils represented forms of life that are no longer with us today.
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Example 3

A good example of reworking is the famous fossil footprints at Laetoli, Africa, of an upright walking biped—the University of Chicago’s Dr Russell Tuttle has shown that these are the same sorts of prints as made by habitually barefoot humans.
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