Evolution Flashcards
Evolution
The gradual change of characteristics within a population producing a change in species over time
Natural Selection
The process by which the environment favors one form of a species over another and thus that form reproduces more than the other
Carolus Linnaeus
1700’s guy who created the classification system and thought about how different species are related to one another and where they originated
Frenchy Lamarck
Wrongly proposed that evolution occurs by will not natural selection
Charley Darwin and RUSSELL WALLACE
Came up with the basic theories about evolution that are used today. NATURAL SELECTION
Modern Synthesis
The modern ideas about evolution. GRADUAL EVOLUTION of traits across POPULATIONS.
Gene Pool
The entire collection of genes within a given interbreeding population
Modern evolution theory…
focus on the change that occurs among populations, not individuals
Differential Reproduction:
It assumes that natural selection favors individuals with certain alleles in that Gene Pool and that those certain individuals will reproduce more and thus those alleles will become more and more proliferated
Mutation
An error in the DNA sequence of a gene
Genetic Drift
What happens if for example you had 1000 dogs in the world and 500 (having the same gene pool as the 1000) moved to a different area. Then if 90% of the new 500 died and the 10% that was left over did not have the same gene pool, the gene pool of the 10% would have reduced variety compared to the 500 from the beginning.
Three ways to change gene pools:
Differential Reproduction, Mutation, Genetic Drift
Gene Migration
The introduction of new genes from an immigrant that results in the changing of the gene pool of a population
Hardy-Weinberg Law of Equilibrium
p^2 + 2pq + q^2 = 1
Recessive genes do not disappear over time from a population. In order for it to work there has to be random mating, and no migration, mutation, selection, or genetic drift.
Species
A population that shares common gene pool and fertile offspring
Two ways to make separate species
Allopatric Speciation, and Sympatric Speciation
Allopatric Speciation
Occurs when two populations are geographically isolated from each other allowing for genetic drift, selection, or mutation to cause the populations to differentiate to where the two populations would be unable to interbreed later if they were reintegrated
Sympatric Speciation
Speciation without a change in geography. Could happen with
Adaptive Radiation
(not necessarily to do with species) Occurs when parts of a population spread out to different areas finding their own niche and evolve into new species
Gradualism
The idea that species change very gradually
Punctuated Equilibrium
A scientific model that proposes that species undergo a long period of equilibrium until at some point it is upset buy environmental forces that cause a short period of quick mutation and change
Oparin Hypothesis
(1924) The atmosphere had ammonia, hydrogen, methane, and steam escaping from volcanoes and the earth was very hot and lightningy. Simple organic molecules collected as primordial soup in the oceans and these molecules formed larger, absorptive, and charged complex molecules called coacervates which supposedly formed into proteins and Amino Acids.
Stanley Miller
Provided support for the Oparin Hypothesis. Showed that simple inorganic molecules exposed to lightning could produce amino acids
Sidney Fox
(1960s) Showed that ultraviolet light could form even more complex stuff
Cyril Ponnamperuma
Showed that guanine, adenine, and Ribose could be formed with electric current
Prokaryotic cells…
were the “first” cells
Plant development
Hetrotrophic prokaryotic cells > Photosynthetic autotrophic cells > Pohtosynthetic eukaryotic cells > multicellular photosynthetic organisms in the water > plants on land > development of thicker cell walls and xylem/phloem and seeds, etc.
Precambrian Period
600 Million years ago and before. First descendants of animals supposedly showed up as non-vertibral MARINE PROTISTS.
Paleozoic Era
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian
Cambrian Period
570-505 million years “ago”. Exoskeletons appear. All modern day phyla appear (Cambrian Explosion). Early fish formed. Ended with extinctions
Ordovician Period
505-440 million years “ago”. Development of Land Plants and Fish. First vertebrates. Ended with extinctions also.
Silurian Period
440-410 million years “whatever”. Colonization of LAND which involved new needs.
Devonian Period
400-360 million years ago. First amphibians.
Carboniferous (Mississippian) Period
First Reptiles
Triassic Period
First dinosaurs, mammals, birds
At the end of the Cretaceous period
Dinosaurs died
Cambrian Explosion
The sudden appearance of life forms from all of the different modern phyla in the Cambrian Period.
Homologous (evolution)
Structures that exist in two different species because of common ancestry
Analogous (Evolution)
Structures are similar because of their common function
Convergent evolution
Birds and Dragon flies both have wings and are not related
First Hominids (human family) la la la
4.5 million years ago.
First Homos ( human genus)
1.8 million years ago. walked upright
Cro-Magnon man
First Homo sapiens
This experimental evidence was not considered to support the Oparin Hypothesis
In the laboratory, proteins are not useful as catalysts, indicating that early proteins were stable
First Dinosaurs, Mammals, birds
Mesozoic (Triassic)
Dinosaurs died
End of Mesozoic period, (Cretaceous period)
