Chapter 18: evolution and origin of species Flashcards
artificial selection
when human chose phenotypes we want and breed to create more ideal hybrids and breed (also known as selective breeding)
what were darwin’s postulates
- characteristics are heritable (passed to an offspring)
- the more offspring that are present that can survive creates a competition
- characteristics of offspring vary and variations are heritable
natural selection
idea that organisms that are more adapted to an environment are more likely to survive
how does homologous structures support evolution
the similar construction of these appendages that indicates that organisms share a common ancestors
what are the key ideas of evidence of evolution
- divergent and convergent evolution
- fossil record
- homologous structures
- vestigial structures
- biogeography
- molecular biology
convergence
similarities occur not because of common ancestry but because of similar selection pressures
how does biogeography support evolution
development and presence of species based on a location
- groups that develop in certain regions or continents
- when species develop because of isolation by physical land barriers
how does molecular biology support evolution
- DNA analysis shows that closely related organisms have similar DNA
- evolution of new functions for proteins after mutations occur
What are the misconceptions of evolution
- evolution is just a theory
- individuals evolve: its populations that evolve not the individual
- evolution explains the origin of life
- organisms evolved on purpose
what is a species
a group of organisms that can interbreed and produce viable and fertile offspring
what is a hybrid
a cross between two species
what is a gene pool
a collection of all the variants of genes in a species
what is speciation
the movement of species (the movement of genetic information of a species)
what is allopatric speciation
speciation that involves geographic isolation (this can include anything that changes the environment at all)
what is the ultimate example of allopatric speciation
panagea
what are the three types of allopatric speciation
- dispersal
- vicarience
- adaptive radiation
what is dispersal speciation
happens is when a few members of a species move to a new geographical areas