BIO CHP 16

The processes that have transformed life on earth from it's earliest forms to the vast diversity that characterizes it today.

• -Common Descent with Modification
• -Natural Selection

Where a species can undergo modification throughout generations.

Traits that give an organism an advantage are "selected" for by nature.

-individuals with favorable traits are more likely to leave more offspring better suited for their environment.

Noted dynamic geologic nature of the Earth

-Changes still occuring today

"the inheritance of acquired characterics"

Noted extinction of some species on Earth and the apperance of others within different time-frames

• CATASTROPHISM:
• Earth affected in the past by sudden, short-lived, violent event, possibly worldwide in scope.

Collected many different species and varieties of animals. fouund two main points from the journey


1. species were not created in their present form, but evolved from ancestral species.

2. proposed a mechanism for evolution: NATURAL SELECTION

Understood descent with modification for several years before.


-2 yrs after returning, figured out that natural selection was driving the changes.

It was accepted based on modernization of evolution.

• THESE FACTS HELP PROVE IT
• -genetics
• -fossil record
• -distrubution of organisms

English naturalist is the co-discoverer of natural seledction as the principal process underlying evolution.

• -Radiometric dating
• -Fossils
• -Comparative morphology and embryology
• -Biogeographical evidence (island biogeography)
• -Evidence from gene modification
• -experimental evidence

• Technique that determines the age of objects by measuring the decay of radioactive elements in them.
• ( radioactive elements emit energetic rays during decay)

This technique has confirmed the age of the earth to be 4.6 billion years old.

fossils from same evolutionary periods are found together in same geologic strata

explains common occurrence of homologous physical structures in different organisms


MORPHOLOGY: study of the physical forms that an organism takes

EMBRYOLOGY: study of how animals develop from fertilization to birth

Island biogeography-geographic distribution of species on islands (is explained by the theory of evolution)

Variations in DNA sequences of various organisms are consistent with evolutionary theory

experimental demonstrations of evolution have been carried out in the laboratory and in nature

Many people believe that you have to choose between science and religion. although some idea contradict one another most people prefer to be in touch with science, it makes them closer to their religion.