Concept 14.1 pp

Species are fixed, permanent, unchanging The Earth was less than 10,000 yrs old and unchanged. Awareness of diversity- plants, animals, geological processes people began to challenge these ideas.

Biological history of life. Changes over a long time that transforms life. Influences: 1. *Fossil Study-Georges Buffon –Earth is much older –Specific fossils and certain animals may be similar but not identical –Suggests a common ancestor. 2. *Lamarck first proposed life changes or evolves. –Stated species are not permanent

Lamarck thought using or not using certain body parts allowed organisms to developed characteristics that could be passed on to offspring. Incorrect- no scientific evidence to support this. DNA /genes need to be modified. Lamarck was describing environmental effects.

An inherited characteristic that improves an organism’s ability to survive and reproduce in a particular environment. Examples of adaptations-

1831- HMS Beagle 5 year voyage. Darwin made observations in South America. Plants and animals of South America are distinct from species of Europe. Species living in South America were descended from an ancestral species on that continent. Darwin’s observations cause him to question his view. 3. Darwin’s Voyage

A chain of volcanic island off west coast of South America. Darwin notices most species are similar, but different from the nearby mainland. Darwin infers species changed and adapted after they colonized the islands. 4. *Lyell’s geological studies influence Darwin –Gradual – slow processes –Erosion and earthquakes explain fossils of marine animals found in the Andes. –Conclusion- Earth must be very old.

5. *Malthus essay- Human suffering –Human population growth rate is increasing faster than food and resources are available. –Limiting factors. –Darwin realizes this concept applies to all species. 6. *Alfred Wallace describes the same idea of evolutionary change. –Prompts Darwin to publish his ideas.

Darwin – published in main points- 1. Descent with modification- explains diversity of life. Species on Earth today descended from ancestral species. They spread into various habitats occurred over millions of years. In their habitats they accumulated different modifications ( adaptations). Examples of adaptations.

2. Natural Selection Individuals with inherited characteristics that are best suited will leave more offspring. Over time this can cause a change in the characteristics of a population. Natural Selection is a cause of evolution. Adaptation is the result of evolution. Natural Selection differs from selective breeding which occurs in a shorter time frame because man picks those to breed.