Theory+of+Evolution

Evolution Home 1 Evolution Definitions 2 Evidence of Evolution 3 Charles Darwin 4 Theory of Evolution 5 Study Resources

=Theory of Evolution= 21. What is Evolution? generation-to-generation change in the proportion of different inherited genes in a population that account for all of the changes that have transformed life over an immense time. The process by which modern organisms have descended from ancient organisms. Does not occur in one generation.

Evolution is a change in genes in a organism to survive in the environment. this change occurs over a large period of time and through generations.

22. What is a population? A species contained in a certain area, usually separated by a natural landmark (rivers, cliffs, oceans etc..).

What are the two main sources of genetic variation in a population? 1)Mutations (Main source and foremost source of variation) 2)Recombination (The crossing over of chromosomes between gametes gives new sequences/i.d. sex) 3)Gene flow (Occurs when an outside individual has different alleles than the new population it moves into.)

24. What is speciation? The formation of new biological species by the development or branching of one species into two or more genetically distinct ones. This usually occurs because of a geographical isolation.

25. What are the three patterns of evolution and how do they differ from each other? Give an example of each pattern.

26. What is an an adaptation? What is the difference between a behavioral, structural, and physiological adaptation? BE ABLE TO GIVE EXAMPLES An adaptation is inherited characteristic that improves an organism's ability to survive and reproduce in a particular environment. Behavioral-special ways a particular organism behaves to survive in its natural habitat. Chipmunks hibernate and can avoid food and water shortages. Structural- special body parts of an organism that help it to survive in its natural habitat (skin color, shape, body covering). A Kangaroo has gained powerful muscles in their large hind legs that help the animal move quickly and efficently. Physiological-systems present in an organism that allow it to perform certain biochemical reactions (e.g., making venom, secreting slime, being able to keep a constant body temperature). In humans the amount of melanin produced in the skin serves as a protection against UV radiation.