Evolution+Definitions

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

=Evolution Definitions=

1. 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

Includes that modern organisms came from older organisms. And Charles Darwin is the person who came up with the theory as well as other scientist who have added to the theory, such as Malthus and Wallace.

The process by which modern organisms have descended from ancient organisms. Does not occur in one generation.

2. Population Group of individuals of the same species living in a particular area at the same time. 3. Species group of individuals sharing common characteristics and qualities and able to reproduce with each other.

4. Natural Selection Process by which individuals with inherited characteristics best suited for the environment, other wise known as survival of the fittest, leave more offspring with than do other individuals.

5. Homologous Structures Similar structure, due to common ancestors, but different functions

6. Analogous Structures Similar function but evolved separately (different ancestor)

7. Vestigal Structures No current function, but there was a function in an ancestor.

8. Fossil any remains, impression, or trace of a living thing of a former geologic age, as a skeleton, or footprint

9. Law A general statement about nature that is considered proven beyond doubt

10. Theory A proposed explanation for an idea or concept.

11. Hypothesis An educated guess or explanation as a tentative answer for a specific problem.

12. Microevolution Change within a species that can occur in a human's lifetime.

13. Adaptation any alteration in the structure or function of an organism or any of its parts that results from natural selection and by which the organism becomes better fitted to survive and multiply in its environment.

14. Speciation The formation of new biological species by the development or branching of one species into two or more genetically distinct ones. The divergence of species is thought to result usually from the geographic isolation of a population, especially when environmental conditions that vary from those experienced by the rest of the species, and from the random change in the frequency of certain alleles, also known as a genetic drift.

15. Genetic Variation The extent of variation in natural populations is such that every individual must be genetically unique. It refers to the variation of a population or species.

16. Biogeography The study of the geographic distribution of organisms. The scientific study of the geographic distribution of plant and animal life. Factors affecting distribution include the geologic history of a region, its climate and soil composition, and the presence or absence of natural barriers like deserts, oceans, and mountains. Biotic factors such as interactions among competing species, coevolutionary influences, and the reproductive and nutritional requirements of populations and species are also studied

Biogeography is the study of the the geographic distribution of organisms.

17. Stratum One of several parallel layers of material arranged one on top of another. A single bed of sedimentary rock, generally consisting of one kind of matter representing continuous deposition.

18. Law of Superposition A basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

19. Survival of the Fittest A concept relating to competition for survival or predominance. It's more formal name is "natural selection", which scientists rather use.