Science Evolution Flashcards
-Refers to a change in a population of organisms over time
Evolution
-An economist
-“An Essay on the Principle of Population”
-Population growth = Availability of food
-“Artificial selection”
–Influence Charles Darwin
Thomas Robert Malthus
-Systema Naturae
-A book made by him
-He grouped plants and animals according to their similar characteristics
Carolus Linnaeus
Theory
-The characteristics that an animal acquired during its lifetime in order to adapt to its environment can be passed on to its offspring
-If certain body structures are not used, they would disappear; and if a body structure was utilized often, it would develop further
Theory of Inheritance of Acquired Characters
-Proponent: Jean-Baptiste Lamarck
Theory
-States that natural history has been punctuated by catastrophic events that altered that way life developed and rocks were deposited
Theory of Catastrophism
-Proponent: Georges Cuvier
Theory
-The needs of the animals have nothing to do with how they evolve and changes in an organism during its lifetime do not affect the evolution of the species
-Survival of the fittest
Theory of Natural Selection
Proponent: Charles Robert Darwin
-Slight difference in an inherited trait of individual members of species
-Variations arise naturally in population
-Phenotypes can be passed on to generation
-Is a result of sexual reproduction
Variation
-Increases an organism’s chance of surviving and reproducing in its environment
-Structural and behavioral
Adaptation
-Jackrabbit’s powerful hind legs help them to run fast to escape predators
Structural Adaptation
-Is the process whereby organisms that are better adapted to their environment tend to survive and produce more offspring
-Only organisms that can adapt to environmental conditions will survive
Natural Selection
-Competitions exist among organisms and only those who fit will survive
-Failure to change will lead to extinction
Survival of the Fittest
-Is a process by which new species are formed
-When favorable traits are acquired, new species come to existence
Speciation
-Is the process by which a plant or an animal becomes
-………. found in younger rocks are not found in much older rocks
-The remains of many ancient organisms show structural similarities to certain organisms that exist today
Fossilization
-Is the study of the development of embryos from fertilization to birth
Embryology
-Similar physical features in organisms that share a common ancestor
-But they serve completely different functions
Homologous Structures
-Limbs of different species that are similar in function but not necessarily in structure
-Do not derive from a common ancestor
Analogous Structures
-Organisms that are considered to have lost much or all of their original function through evolution
Vestigial Structures
-Provides a record of how creatures evolved and how this process can be represented by a ‘tree of life’, showing that all species are related to each other
-Are skeletons
Evidence: Fossil Records
-Comparative study of embryos in vertebrates shows that there is lot of similarity in them at the initial stages whereas this similarity decreases gradually
Evidence: Embyrological Evidence
-Observing anatomical features shared between organisms
Evidence: Structural Evidence
-The more closely related the species are, the more similar their genes are
Evidence: Biomechanical Evidence
-Transfer of alleles from the former population to another population
-In recent years,this
has been observed between the Caucasian population and the African-American population
-African-Americans are resistant to malaria whereas Caucasians are not
-The offspring produced were seen to be resistant to the disease
Gene Flow
-The change in allele frequencies that are due to chance which causes a loss of genetic diversity in a population
-Some alleles will decrease in frequency and become eliminated
Genetic Drift
-Extreme example of genetic drift that happens when the size of a population is severely reduced
Bottleneck Effect
-Occurs when a small group of individuals breaks off from a larger population to establish a colony
Founder Effect
-New alleles can form through mutation that will create another genetic variation needed for evolution
Mutation
-Unique traits of animals improve mating success for evolution
Sexual Selection
-Happens when males display unique traits that attract females
Intersexual Selection
-Happens when there is a competition among males
Intrasexual Selection
-The evolutionary process by which populations evolve to become distinct species
Speciation
