1. Darwin Developed a Theory of Evolution
Concept 14.1
Darwin Developed a Theory of Evolution

2. Ideas from Darwin’s Time
A new view of life came into focus in 1859, when Charles Darwin published his book the Origin of Species, Darwin’s ideas provided a framework for understanding Earth’s diversity of organisms and their relationships to one another and their environment.

3. Evolution
Generation-to-generation change in the proportion of different inherited genes in a population that accounts for all changes that have transformed life over an immense time.

4. Adaptation
An inherited characteristic that improves an organism’s ability to survive and reproduce in a particular environment.

5. The Voyage of the H.M.S. Beagle
The intent of the voyage in 1831 was to set sail and chart stretches of the South American coast. Darwin’s job was to document the plants, animals and geology encountered during the voyage, but more came from it.

6. The Galapagos Islands
This is an island area about 600 miles of the coast of South America. Here Darwin made many observations. There were many unique animals here that were similar but different from the animals on the mainland.

7. Descent with Modification
He proposed that the descendants of the earliest organisms spread into various habitats over millions of years. In these habitats, they accumulated different modifications or adaptations to diverse ways of life.

8. Natural Selection
It is the process by which individuals with inherited characteristics well suited to the environment leave more offspring on average than do other individuals.
Key to natural selection is offspring is not power or speed, although this will help.

9. Concept 14.2
Evolution has left much evidence.

10. Fossils
Preserved remains or markings left by organisms that lived in the past.

11. Fossil Record
It is the chronological collection of life’s remains in the rock layers, recorded during the passage of time.

12. Extinct
These are species that no longer exists on Earth.

13. Similarities in Structure
Homologous vs. Analogous

14. Homologous Structures
These are characteristics that share a common ancestor.
The limbs of the following organisms:
Human
Cat
Whale
Bat

15. Analogous Structures
These are structures that share no common ancestor.
Wings of a bird and the wings of a bat.

16. Population Genetics
It is the study of evolution from a genetic point of view.

17. Microevolution
It is defined as a change in the collective genetic material of a population. (Alleles)

18. Bell Curve
It is a graph of the frequency of a particular occurrence.

19. Gene Pool
It is a term used to describe the total genetic information available in a population.

20. Allele Frequency
How often an allele occurs in a population.

21. Phenotypic Frequency
It is equal to the number of individuals with a particular phenotype divided by the total number of individuals in the population.

22. Immigration
It is the movement of individuals into a population.

23. Emigration
It is the movement of individuals out of a population.

24. Gene Flow
It is the process of genes moving from one population to another.

25. Sexual Selection
Possessing traits that favor the opposite sex for reproductive means.

26. Stabilizing Selection
Individuals with the average form of a trait have the highest fitness.

27. Disruptive Selection
Individuals with either extreme variation of a trait have a greater fitness than individuals with the average form of the trait.

28. Directional Selection
Individuals that display a more extreme form of the trait have a greater fitness than individuals with an average form of the trait.

29. Speciation
The process of species formation.

30. Geographic Isolation
It is the physical separation of members of a population.

31. Allopatric Speciation
This happens when species arise as a result of geographic isolation.

32. Reproductive Isolation
It results from barriers to successful breeding between population groups in the same area.

33. Sympatric Speciation
It occurs when two subpopulations become reproductively isolated within the same geographic area.

34. Gradualism
The idea that speciation occurs at a regular, gradual rate.

35. Punctuated Equilibrium
It refers to a sudden rapid change.