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34 terms

Biology chapter 15 &16 test- freshman

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Theory
well supported testable explanation
Evolution
change in living things over a period of time
Fossil
preserved remains or evidence of an ancient organism
Artificial Selection
when humans can select variations of organisms that are useful & breed these individuals
Struggle for existence
competition among members of species for food, space etc.
Fitness
ability of an organism to survive & reproduce
Adaptation
inherited trait that increases an organisms survival
Survival for the fittest
also called natural selection; when individuals are better suited to environment
Natural Selection
how evolution occurs; changes in inherited traits of population
Common Descent
all species, living & extinct, came from 1 common ancestor "tree of life"
Gene Pool
all genes in a population
Gene frequency
how common a gene is in a population
Single gene trait
trait controlled by a *single gene (2 alleles)
Polygenic trait
trait controlled by *more than 1 gene
Speciation
process of forming new species
Reproductive Isolation
species may be able to mate & the resulting offspring may be okay to reproduce, but if they aren't fertile than they can't
Behavioral Isolation
when 2 populations are able to breed but have differences in reproductive behavior that prevents mating
Geographic Isolation
when 2 populations are able to breed but are seperated by barriers (Mountains, Rivers)
Temporal Isolation
when 2 populations are able to breed but reproduce at different times
Hutton 1785
said earth is shaped by geological forces over time
Malthus 1798
said if human population continues to grow there wont be enough space and food
Lamarck 1809
first to propose an explanation of how things change over time; wasn't correct
Lyell 1833
processes occuring now have shaped the earth
Wallace 1858
writes to darwin about natural selection
5 types of evidence that support Darwins theory
Fossil record
Geographic distribution
Homologous structures
vestigial structures
similar embryology
Fossil record
shows gradual changes over time
Geographic Distribution
different locations (environments) that can cause variety of organism changes
Homologous Structures
organisms with similar body structures share common ancestor (similar function & structure)
Vestigial Structures
structure with no function (human apendix)
Similar Embryology
development of vertebrates are very similar
2 sources of variation in a population
Mutations
Gene shuffling
Mutations
change in DNA sequence
Gene Shuffling
when genes form new combinations during prophase 1 of meiosis
1831-1836
Time period when Darwin traveled & developed his ideas