Flashcards in Evolution Study Guide Deck (38)
different levels of success in reproduction based on the ability to survive in the environment (filters out the weak and the strong survive and are successful).
Who came up with the theory of natural selection?
Darwin came up with this theory.
first attempted organization of nature, 2 different worlds (Real and perfect - world of the gods) (Illusory and Imperfect - Earth (birth defects))
Scala Naturae - each species has its own rung on the ladder of life, the position is perfect and permanent
Father of Taxonomy, Binomial Nomenclature
Theory of Catastrophism (explains why organisms seem to disappear from existence on the Earth)
explains why organisms seem to disappear from existence on the Earth
Theory of Catastrophism
contributed that evolution takes a long time
What are the levels of taxonomic classification? How do you scientifically name an organism?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. An organism is named by “Genus species”
wrote Principles of Populations and said more organisms are born than nature can allow to survive (survival is based on the traits an organism possesses)
What did Malthus say about the number of organisms in nature?
He said more organism are born than nature can allow to survive
What is artificial selection? Give an example.
man selects what traits are desirable (Ex. domestic animals and plants)
What defines a population? (4 things)
Same species, same place, same time, and showing signs of reproduction
What are homologous structures? What do they help prove? Give various examples.
Homologous structures - similar structures among different species. They help prove common ancestors among species (Ex. skeletal structures, limb structure, cephalization)
structures that have the same function but they don’t indicate common ancestry
organisms that only appear to be closely related due to that they evolved in similar environments under similar environmental pressures.
What are the two equations for Hardy-Weinberg Theorem? What does each variable represent?
p + q = 1 p2 + 2 pq + q2 = 1
p is dominant alleles, q is recessive alleles, p2 is homozygous dominant, 2pq is heterozygous, and q2 is homozygous recessive
What 5 conditions must be met for a population to be in Hardy-Weinberg equilibrium? Why are these factors important for equilibrium?
Large population, no migration, no mutations, random mating, no natural selection (nature favors equally). These factors are important because they ensure nothing will happen to break the equilibrium.
different traits exist within a given species or population
Describe 3 sources of variation that come about because of sexual reproduction.
The process of crossover, the separation of chromosomes during anaphase I and II, and the random fertilization of an egg by a sperm
the “bell curve” for a trait flows in one direction only
the “bell curve” for a trait separates in opposites directions at the same time
the “bell curve” moves to the “stable” center
What are the three types of evolutionary flow?
Directional, Diversifying, and Stabilizing
competition within one sex (Ex. Males mainly fight for reproductive rights)
competition between the sexes (Ex. Males strut to attract the females attention)
a geologist (someone who studies rocks and earth’s processes). He proposed the theory of gradualism.
tries to explain that the earth must be very, very old because in order for some processes to occur, such as mountain formation or canyon formation, it would require enormous amounts of time.
Theory of Gradualism
a geologist who wrote the Principles of Geology and proposed the Theory of Uniformitarianism
the same geologic processes that are occurring now are the same that occurred in the past
Theory of Uniformitarianism
uses the different strata of rock and index fossils to establish a time line
fossils that we know a specific time period for when they exist.
uses the half-life of radioactive elements that accumulate in an organism over time (C-14 used for thousands, U-238 used for millions and billions)
Absolute "Radiometric" Dating
a famous Harvard professor who proposed the idea of punctuated equilibrium
long periods of stability(this is the equilibrium) are interrupted suddenly(this is the punctuated) by a major disruption(such as an asteroid hitting the earth) that causes a mass extinction of existing species to occur. Once all disruption has calmed down(usually after several years), a mass evolution of new species will occur to occupy all the new open niches that were created due to the mass extinction. (These punctuations usually mark/cause the end of an era.) (Ex. Snowball Earth, Pangaea, and the Asteroid)
an evolutionary tree based on similar characteristics
What does a “Y” shaped region in a cladogram indicate?
The “Y” indicates common ancestry