Echology Chap4 Flashcards
Evolution
Scientific theory that explains the change in the generic composition of a population from generation to generation
Adaption
Inherited characteristics that helps a species to survive and to reproduce in a particular environment
Variation
Visible or invisible differences between one species and other members of a population
Causes of variation
• sexual reproduction
• mutations:
- mistakes copying DNA
- mutagens
Selective Advantage
Characteristic that improve’s an individual’s chance of survival, usually in a changing environment
Natural Selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits
Lamarck’ Theory
Parts of body used extensively become larger and stronger, while those that are not used deteriorate. An organism can pass these modifications to it’s offspring
What does natural selection need to occur?
A variety or diversity within a speies
Darwin’s Theory: Survival of the Fittest
1) overpopulation
2) competition/ struggle of Existence
3) Variation
4) survival of the fittest
5) Origins of New species/ speciation
Overproduction
More offspring are produced than are intended to survive
Competition/ struggle of existence
Because of overpopulation, organisms will compete for all resources
Variation “Darwin’s Theory”
There is a great deal of variation within any given species. The greater the amount if variation within a species the greater the chance of survival
Origins if new species/ speciation
Combined changes in a population lead to the development of a new species.
You know you have a new species if it is incapable of producing viable offspring with members of population that genetically resemble it
The theory of evolution is based on:
1) change on DNA (mutation) which gives variation to a population
2) pressure from environment that will either select for or against certain traits
What does the theory if evolution by natural selection attempt to explain?
Why living things, so similar in their biochemistry and molecular biology, are so different in function
Divergent Evolution
The process of two or more related species becoming more and more dissimilar
Convergent evolution
The process where unrelated species become more an more similar in appearance as they adapt to the same kind of environment
What is the study of fossil?
Paleontology
Transitional Fossils
New discoveries of fossils, that help to fill on the gaps in the fossil record
How neutralists determine the age of different fossils?
Radiometric dating is used to determine the age of fossils.
• Relative Dating
• Index fossils
Relative Dating
Determines the sequential order of a series of events
Index fossils
Used to define and identify different geologic periods
What is biogeography?
The study of distribution of life in Earth
Anatomical Evidence
Similarities exist between different species that suggest common ancestor/ origin
• homologous structures
• analogous features
Homologous structure
- similar in origin (appearance)
- common ancestor
- different function/ use
Analogous Features
- similar appearance
- similar function
- different origin (ancestor)
Vestigial Features
Structures that have no useful function/ purpose in modern organism but most likely had a use in an ancestral form
Physiological Evidence
Certain chemicals in organisms as well as the function of these chemicals are similar if bot be the same.
•Hormones
•Thyroxin
Biochemical Evidence
Similarity in DNA sequences; used to determine similarities and common ancestory
Artificial Selection
Human’s selecting and breeding organisms with specific trait
