Chapter 17 Evolution

"Survival of the fittest" It brings about evolutionary change.

Structures found in different species that are anatomically similar because they have been inherited from a common ancestor. Example: Page 296 Forelimbs

Serve the same function but are not constructed similarly. Ex: Birds and Insects have wings.. but are totally different.

Remains of an anatomical structure that are functional in an ancestor but are not currently functional. Examples: Humans have a tail bones, Snakes remnants of apewic girdle and legs.

Evolution is considered a unifying theory of biology. It explains the unity and diversity of life. 1)Descents from a common ancestor explain the unity of life. 2) the unity of life = living things share a common chemistry and cellular structure (DNA, RNA and cell membrane). 3) Adaptions to a particular enviroment explains the diversity of life.

Environmental factors and influence on survival

Organisms that are better adapted to the environment will survive and reproduce in greater numbers.

1)Descents from a common ancestor 2) adaption to the enviroment.

1)Descents from a common ancestor explain the unity of life. 2) the unity of life = living things share a common chemistry and cellular structure (DNA, RNA and cell membrane). 3) Adaptions to a particular enviroment explains the diversity of life.

4 billion years old. LIfe began about 3.8 billion years ago. Humans appeared about 100,000 years ago.

Darwin concluded that adaption to the environment accounts for diversification. He studied the finches that he collected from the Galapogos Islands for many Years. He concluded that one species rise to 14 different species. The finches' beaks adapted to its particular diet.

Wallace: proposed natural selection as a process to explain the origin of species. Lyell: Wrote the Principles of Geology which supported theories of geologic change. Cuvier: Found the science of paleontology (study of fossils) Malthus: Stated that death and famine were inevitable due to population increases.

1) Membrers of a population ahve heritable traits. 2) In a population, more individuals are produced each generation that the enviroment can support. 3) Some individuals have adaptive characteristics that enable them to survive and produce better than other individuals.

1) Increasing proportions of individuals in succeeding generations have the adaptive characteristics. 2) A population adapted to its local environment.

Fossil evidence - Fossils must be atleast 10,000 years old. Fossils show change over time. The only flaw is that organisms without bones, exoskeletons, etc are not part of record. ---- Biogeographical evidence - Geographic distribution of plants, and animals throughout the world. (Pangea) ---- Anatomical Evidence - There are anatomical similarities that serve the same function but are constructed differently. ---- Biochemical Evidence - Almost all organisms use DNA and the same triplet code and 20 amino acids - they also use ATp and nearly identical enzymes. -Many genes are similar.