Darwin’s Theory Of Natural Selection Flashcards
Remains of once-living species often preserved in sedimentary rock.
Fossils
Interpreted the Bible literally.
Calculated the world was created in 4004 BC.
Irish Archbishop Jame Ussher
Calculated earth must be at least 75,000 years old.
Speculated humans and apes could be related to each other and that species could change over time.
George Lewish Leclerc
Charles Darwin’s grandfather.
All life had common ancestor.
Discussed forms of selection.
Erasmus Darwin
Advocate of transformationalism. —> Specifically inheritance of acquired characteristic traits.
First to publicly state view of evolution and to propose mechanism for how evolution takes place.
Organism strives to adapt itself to its environment, acquiring traits that can be passed on to its offspring.
Jean-Baptiste Lamark
The use or disuse of a body part results in heritable change.
Transformationalism
Geologist. Suggested that Earth was powered by an interior source of heat.
Introduced ideas of uniformitarianism.
James Hutton
The laws of physics and chemistry don’t change over time (CONSTANT).
Past geological events are driven by processes analogous to those that continue to occur today.
Uniformitarianism
Geologist. Built on Hutton’s work.
Darwin read his work and influenced his understand that Earth must be very old and geologic change happens slowly and steadily over time.
Charles Lyell
Human populations increase at an exponential rate before eventually exceeding the capacity of their environment.
2 types of mechanisms to maintain populations at a size that could be supported by limited resources in their environment: increasing death rate (positive checks) or decreasing birth rate (preventative checks).
Thomas Robert Malthus
A breeding group of individuals of the same species living in a common area.
Population
Explains the principles of natural phenomena using a body of inter connected observations.
Scientific Theory
Major types of variation among species:
(species can be distinct)
Global Differences
Local Differences
Temporal Differences
Look very different in one part of the world (continents isolated from other continents or islands far from the mainland).
Because of climate or isolation.
Global Differences
Species vary across geographic areas.
Organisms looked similar had variations that depended on their ecological niches.
Because of ecological niche.
Local Differences
Species change over time, which causes differences amount member of the same species.
Because of changes over time.
Temporal Differences
5 major theories of Darwinian evolution:
Perpetual Change
Common Descent
Multiplication of Species
Gradualism
Natural Selection
Theory of Darwinian evolution:
The living world is constantly changing. —> The fossil record documents the long history of living organisms.
Perpetual Change
Theory of Darwinian evolution:
All life originated from a shared ancestor. —> Supported by comparative anatomy, developmental biology, embryology, and molecular biology.
Common Descent
Theory of Darwinian evolution:
New species evolve by existing species splitting and transforming.
Multiplication of Species
Theory of Darwinian evolution:
Many small, steady changes produce notable trait differences over a long period of time.
Gradualism
Theory of Darwinian evolution:
Natural forces favor new adaptations. —> Individuals in a population are in a continuous strudels to survive because of limited natural resources.
Natural Selection
Traits that give an organism an advantage for living in a particular environment.
Adaptations
The “fittest” individuals have the greatest reproductive success.
Survival of the Fittest
The ability of an individual to pass along genes to the next generation.
Fitness
(Reproductive Fitness)
Evidence of Evolution:
-Fossils
-Comparative Anatomy
-Biogeography
Physical features that share form and/or function as a result of common ancestry. —> Can demonstrate modifications over time. Anatomically similar.
ex. giraffe’s 7 cervical vertebrae and mouse’s 7 cervical vertebrae
Homologous Structures
Homologous Structures
Physical features that remain in a species BUT have no current function. —> These species inherit their structures from common ancestors, demonstrating their evolutionary history.
ex. birds with wing structures but don’t fly (Ostriches).
ex. human tailbone and wisdom teeth
Vestigial Structures
Serves a related function but aren’t constructed in the same way.
ex. wings of birds and bats —> These wings didn’t arise from a common ancestor… Allow them to fly BUT anatomical structures different.
ex. flippers of dolphin and fins of shark
Analogous Structures
Explains the distribution of organisms through the world and abiotic (non-living) factors that induce their distribution.
Biogeography
Native and restricted to a specific area.
Isolated species have evolved to be quite different from their relatives on the mainland (islands vs. mainland).
Endemic Species
Examines individual development.
Developmental Biology
Looks at inheritance and variation.
Genetics
Proves evolutionary changes through shared DNA sequences and cellular components.
Molecular Biology
Produces organisms with desirable traits (which show the heritability of traits).
Artificial Selection
The development of an individual over the course of its life.
Ontogeny
How a species or population evolves over time.
Phylogeny
Studies the early embryonic stages of development.
Embryology
Different versions of the same gene.
Alleles
Defined evolution as changes in allele frequencies within populations and identified several forces of evolution that influence changes in allele frequency.
Combination of modern genetics and Darwinian evolution and was the strongest evidence yet supporting Darwin’s ideas.
Modern Synthesis
