Evolution Flashcards
Chapter 8
What is evolution
The process by which species of organisms change over time through variations in traits, which are passed down through generations.
State the theory of special creation
Life was created by a supernatural being at a particular time as stated in Gensis 1-26
State the theory of spontaneous generation
Life arose from non-living matter on numerous occasions
State the theory of steady state
The theory states that the earth and universe never had an origin
State the cosmozoan theory
This theory states that life arrived on this planet from elsewhere
State the theory of Biochemical Evolution
States that life arose according to chemical and physical laws
What is convergent evolution
He processes in which species that are not closely related to each other indirectly evolve similar traits
What is an example of convergent evolution
Dragonflies, hawks and bats that all have wings
What is divergant evolution
The procces in which a trait held by a comman anscestor evolves into diffrent varations overtime
What is an example of divergent evolution
The evolution of whale flippers, frog forelimbs and human arms from the the front flippers of an ancient fish
What is speciation
Speciation is the process by which new and distinct species evolve from a common ancestor
What is allopatric speciation
When a population becomes separated into two entirely isolated subpopulations
-Natural selection and genetic drift operation each subpopulation independently
What is peripatric speciation
Occurs when a very small subpopulation becomes isolated from a much larger majority and diversion happedns rapidly
What is parapatric speciation
When a small subpopulation stays in the same habitat but enters a different niche
What is sympatric speciation
Rarest from of speciation that occurs with no form of isolation
What is Parallel Evolution
Occurs when diffrent species start with simialr ansesteral origigns, then they evolve simialr traits over time
What is an example of Parallel Evolution
The evolution of plant leaves into distinct forms from common ancestor
What is coevolution
Occurs when closely interacting species exert selective pressures on each other, so they evolve together
What is an example of coevolution
The relationship between flowering plants and their pollinators
Flowers evolve traits that attract specific pollinators, such as bright colors, sweet scents, and nectar. Some flowers even have shapes that fit the beak or tongue of particular pollinators.
What is the Geological time scale?
The Geological Time Scale (GTS) is a system geologists and paleontologists use to organize Earth’s history into different time intervals.
What is Lamarckian Theory of Evolution?
States that the mechanism of evolution is based on us and the disuse of parts and Inheritance of acquired characteristics
What does excessive use lead too?
Leads to increased size and/or increased efficiency
What does excessive disuse lead too?
Leads to degeneracy and atrophy
Who proposed the theory of natural selection
Darwin and Wallace
What is The Theory of Natural Selection (Darwinism)?
The natural phenomenon by which those organisms that appear physically physiologically an behaviorally better adapted to the environment survive and reproduce
State Darwinism: Observation 1
Indviduals within a popualtion have great repoduction potential
State Darwinism: Observation 2
The number of induals in a population reamins constant
State Darwinism: Deduction 1
There is a struggle for existence within a population
State Darwinism: Observation 3
Variations exist within all populations
State Darwinism: Deduction 2
In the struggle for existence, individuals showing variation best adapted to their environment have a reproductive advantage
What is Variation
The difference sin characteristic shown by organism belonging to the same population
What is Continuous Variation
The gradual change of character from one individual to another
e.g. skin color, length of leaves, height
Discontinuous Variation
The type of variation when there is a clear difference between characteristics
e.g. blood groups, sex, tongue rolling
What are the causes of Variation
-Gene reshuffling
*Crossing over
*Fertilization
-Mutation
What are the evidences of Evolution
-Geological distrubition
-Comparative anatomy
-Embryology
-Taxonmy
-Palaeontology
Geological Distributuion
Geological distribution refers to the spatial arrangement or spread of certain species, across different regions of the Earth surface
What is Comparative Anatomy?
The comparative study of anatomy groups if animals and plants
CA: What are Homologous Structures
Organism that has similar anatomy due to common structures but different functions
What is an examples of Homologous structure
The wings of birds and the arms of man
CA: What are Analogous Structures
Structures that have similar functions but different evolutionary organism
What is an example of an analogous structure
Wings in birds and insects
CA: What are vestigial structures
Reduced or non-functional remnants of ancestral traits
What is an example of vestigial structure
A bat’s third digits are reduced while its fourth and fifth digits are missing
-human tailbone
What is molecular biology
The similarities in the DNA and proteins of animals
What is an example of molecular biology
The presence of similar biological molecules such as nucleotides, ATP, and other organelles
What is embryology
Similarities in embryonic development stages indicates common ancestry
What is an example of embryology
The presence of branchial groves and segmentation myotomes in human embryos is suggestive of fish ancestry
What is Paleontology (Fossil Record)
Shows transitional forms linking ancestral and descendant species, supports gradual change over time
