History Flashcards
Latin “evolutio” meaning?
unravelling
“nothing in biology makes sense except in light of _____” - _____
evolution
Dobzhansky
agents of evolution (5)
non-random mating
dispersal/gene flow/migration
mutations
gene drift
natural selection
Anaximander in Ancient Greece
species were formed from water, humans and other animals came from fish
Empedocles
heads, limbs, and other organs were joined at random and only some combinations survived
Plato
each nature type of object in the observed world is an imperfect manifestation of the ideal
Aristotle (student of Plato)
thought of a static world in which a deity created fixed essenses
- Christianity expanded: Great Chain of Being
where did species originate? (2 theories)
- theory of special creation
- descent w modification
theory of special creation
- created by a deity
- species were created independently of one another
- species remain the same since creation (variation in species is minor/limited)
- Earth and life are young
descent w modification
- species change over time (microevolution)
- lineages split and diverge (speciation)
- new life forms come from older forms (macroevolution)
- all life forms are related (common ancestry)
- earth and life are old
carl linnaeus
- classified plant morphology -> classes, orders, genus, species
- binomial nomenclature (genus + species) in “Systema Naturae”
Erasmus Darwin (Charles Darwin’s grandpa)
- “Laws of Organic Life”
- integrative approach
- survival of fittest/most competent will propagate, thus improving species
Jean Baptiste Lamarck
- “Philosophie Zoologique”
- all species derived by gradual change from other species
- mechanism: inheritance of acquired characteristics
mechanism: inheritance of acquired characteristics
- improved if used a lot, organs reduces to vestiges from disuse
- required that bodily changes can be registered in germ cells
catastrophism vs uniformitarianism
catastrophism - biblical interpretation of earth history (e.g. biblical flood)
uniformitarianism - more modern view of earth history (unimaginably old, present landforms resulted from still-occurring geological processes, originated from James Hutton-late)
Charles Lyell
- “Principles of Geology”
- challenged belief of earth history and age; argued it is hundred of millions of years old, geology created through natural forces
Charles Darwin - South America (Voyage of the Beagle)
fossils no longer extant in region
- species can go extinct
fossils in region were diff from modern-day equivalents
- species have ancestors and change through time
travelling from N to S, one species replaced by similar but a bit diff species
- species differ across space/geography
Charles Darwin - Galapagos Islands (Voyage of the Beagle)
tortoises diff from island to island
- isolation (water channels), cannot move to other islands/populations
finches similar^
- beak shape differences
- also isolated -> evolved differently
fossil records
- species go extinct
- law of succession (extant species resemble past fossils in same area)
- transitional forms (e.g. archaeopteryx lithographica = transitional form btw dino & bird)
- env change
transitional form between dinosaurs and birds
Archeopteryx lithographica
Charles Darwin - Home in England (Voyage of the Beagle)
vestigial organ
homology
artificial selection
read “An Essay on the Principle of Population” - Thomas Robert Malthus
vestigial organ
functionless or rudimentary ver of body part which has important function in similar species
homology
the study of likeness
- same organ in diff animals under every variety of form and function (think arm bone in human, cat, bat, whale)
artificial selection
humans have modified species over time to suit needs through selective breeding
“An Essay on the Principle of Population”
Thomas Robert Malthus
- reproductive capacity of human population exceeds food supply
- humans compete among themselves
- process would also occur in nature, “natural” selection without a plan or conscious
Alfred Russel Wallace
Malay Archipelago
- Wallace’s Line: a deep water channel where one side of islands had Australian-looking sp, other islands had Malay-looking sp
- read essay by Malthus
- idea of natural selection
- wrote “On the Tendencies of Varieties to Depart Indefinitely from the Original Type”
___ and ___ announced Darwin and Wallace ideas at _____________
essay name: ____
Lyell
Hooker
Linnean Society of London
“On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Race in the Struggle for Life” AKA “ The Origin of Species”
Linnean Society of London
- forum for discussion in genetics, natural history, systematics, biology, history of plant/animal taxonomy
- oldest extant biological society
- named after Linneaus
What could Darwin not explain?
- how a given trait is transmitted from parent to offspring
- where/how new traits appeared
Gregor Mendel
experiments in plant hybridization using pea plants
- pod shape/colour, seed shape/colour, flower colour
credited for laws of heredity
traits are passed from parent to offspring through gametes in genes (alleles), and individuals are diploid
Gregor Mendel’s Principles (2)
First principle - Principle of Segregation
- each gamete can only carry one allele from a parent for one gene
Second principle - Independent Assortment
- segregation of members of one pair of alleles occurs independently of -> the segregation of members of another pair of alleles during gamete formation
