evolution
the process of genes changing over generations
the "steps" of natural selection
genetic variation offspring who form genetic mutation as a result of their environments have adapted (survival of the fittest) mutated offspring go to have children and pass down adaptions to offspring
how can natural selection cause evolution in a population of organisms?
Evolution relies upon the notion that mutated traits are passed on from mutated parents that have adapted to their environment and survived in a large population. This relies on the knowledge that only those with suitable characteristics survive and reproduce, promoting the frequency of an adapted trait, which is natural selection.
what are factors that cause genetic variation in a population
mutation, meiosis, sexual reproduction
what aspect of mutation causes genetic variation?
mutation in the chromosomes causes new varieties of a gene
what aspect of meiosis causes genetic variation?
crossing over in prophase 1, independent assortment in metaphse 1
what aspect of sexual reproduction causes genetic variation?
traits are mixed with each generation of offspring
describe the evolution of beak shape/size in the finches on different islands in the Galapagos
average beak size grew
explain the evolution of beak size/shape in finches on the Galapogos islands
originally finches with larger beaks were able to outcompete finshes with smaller beaks for food, increasign the beak size that way drought in 1977 - made frequency of larger beaks grow because there were no small seeds for smaller beaked finches to feed surviving population of the event passed down the large beak trait
melanistic industrialization
the increase in frequency of a darker melanistic variety as a result of pollution
what was the evolution of the peppered moth population in response to environmental changes in England
greater frequency of darker, melanistic variety of peppered moths in England
explain the evolution of the peppered moth population in response to environmental changes in England
describe the evolution of antibiotic resistant strains of bacteria
some bacteria will develop resistance to an antibiotic and multiply rapidly thanks to binary fission
how are mutated genes exchanged between bacteria
conjugation. plasmids containing mutations are exchanges
how can misuse of antibiotics accelerate evolution of antibiotic-resistant bacteria
when antibiotics are taken in doses higher than reccomended, there is a higher likelihood of mutations becuase the bacteria sense it in greater amounts
why does evolution occur more quickly in populations of organisms that have short lifespans + reproduce quickly
more generations so traits will be passed down quicker
example of selective breeding of domesticated animals, results
great danes: for centuries, humans have chosen the largest male and the largest female dog to crossbreed, which resulted in the Great Dane breed, known as the largest breed of dogs
example of selective breeding of domesticated crops, results
Crossing of certain traits in a plant (vitamin, number of leaves, pigmentation, etc.)has resulted in different varieties of plants that have a high frequency of said trait
homologous structures
similar structures that arise from a common ancestor
adaptive radiation
when a characteristic rapidly multiplies in a population
how do homologous structures arise by adaptive radiation
The characteristics form homologous structures will diverge when adapting to the environment and multiply by adaptive radiation
example of homologous structure
bone structure of vertabrate pentadactyl limbs
analogous structure
structures that do not arise from a common ancestor, instead similar environments
convergent evolution
two organisms develop similar characteristics due to similar environments, not a similar ancestor
example of analogous structure
wings of birds and insects