Exam 1 Flashcards
What is not in Darwin’s theory?
- Evolution creates a new form of life by dramatic mutations
- An organism can evolve during its lifetime
- An organism can influence the evolution of its own structures in response to its environment
- Evolution is a completely random process
What is evolution?
Evolution is the change organisms go throughout earth’s history.
Aristotle’s theory
Fixed ideal species & the ladder of nature
Linnaeus
“father of taxonomy” who made an orderly classification system by grouping similar species into general categories. Also created binomial naming
Theory of Gradualism
Proposed by geologist James Hutton who believed that earth’s geological features are a result from gradual processes
Uniformitarianism
Charles Lyell expanded on Hutton’s idea; the same geological processes in the past as today. Rate of change today = rate of change in past
Erasmus Darwin
(grandfather) first person to formally propose the theory of evolution in his book. He however was not the one to propose natural selection
Lamarck
Linked evolution to adaptations (extinct species could not adapt and therefore went extinct)
Theory of Inheritance of Acquired traits
Proposed by Lamarck; if an organism changes during its life in order to adapt to its environment then those changes are passed onto its offspring (wrong concept, darwin rejected these ideas)
Darwin’s book
Origin of species - 1859
Natural Selection
Survival of the fittest is the reproduction of individuals with favorable genetic traits that survive environmental change bc of those traits. Leading to evolutionary change.
Descent with modification
Darwin proposed that many species on earth are descendants of ancestral past species that were different from today’s species.
Theory of evolution by natural selection
genetic variation is essential for evolution by natural selection. no variation = no adaptations
Fossil records
fossil intermediates seem to be an evolutionary transition between two groups of organisms
Tiktaalik
Represented the transition of organisms from water to land
Archaeopteryx
evolution of bird from reptile
Homology
forms/limbs related by common ancestry and are a result of divergent evolution
Homologous structures
Structures between groups of organisms that have same overall layout and structure. Result of their common ancestor (do not all have the same function)
ex: mammal forelimbs
Vestigial Structures
Fully functional in ancestors but no longer functional to us/present organisms.
ex: wings on flightless birds
Analogous structures
Same function of limb but are not a result of a common ancestor. (no common ancestor but have similar structure with similar function.)
Biogeography
distribution of species which corresponds to geographical history.
Wallace’s line
an imaginary line that explains the variation between organisms in islands a couple miles apart.
Endemic
not found elsewhere
Molecular Biology
- DNA analysis supports evolution
- Closely related organisms have similar DNA
- Evolution of new functions for proteins after mutations. Similar DNA sequences are the strongest evidence for evolution from a common ancestor.
Convergence Evolution
Natural selection acted in the same way under the same conditions. (their similar environmental conditions caused animals to have similar adaptations)
Species
A group of organism that can interbreed and produce viable, fertile offspring (not based on similar appearance)
Speciation
Formation of two species from one original species
Gene Flow
the movement of alleles across a species range. (if gene flow occurs they are same species)
Allele
One of a number of altering forms of a DNA sequence at a particular genetic locus
Biological Species Concept
Members of the same biological species share the same gene pool because there is gene flow between two populations and they are reproductively isolated from other species by natural biological barriers.
Morphological Species Concept
Organisms that have significant morphological and anatomical differences are different species
Temporal Isolation
Species have different breeding schedules
Habitual Isolation
Members of species move or are otherwise separated
Behavior isolation
Certain actions or behaviors (or the lack of them) impacts reproduction
Gametic Isolation
differences in gamete cells prevents fertilization
Mechanical isolation
When mating is impossible between different animal species because of incompatibility
Prezygotic
Before reproduction