Topic 7.8 - Continuing Evolution 𖦹⋆｡°✩ Flashcards
is evolution over. provide an example
no, evolution is an ongoing process in all living organisms and populations of organisms continue to evolve. for example, the finches of the Galapagos Islands
what are the mechanisms of genetic change
༻ changes in DNA - gene/chromosomal mutations
༻ cell division - sexual reproduction to increase gamete diversity, independent assortment, and crossing over
༻ environmental disruptions - sudden changes in environment, changes in allele/gene frequencies within a population
what do strata layers provide
strata layers arrange fossils in the order they were deposited
what do new fossils mark
they mark changes in the environment
how do new selective pressures impact fossils
can result in changes in the frequency of certain adaptations within a given population
what are transition fossils
can show the evolutionary changes as one group evolves into another
what can result in resistance to chemicals through natural selection
mutations can allow resistant organisms to be selected for under conditions where the trait is advantageous
what happens to the frequency of the population of resistant organisms
frequency of resistance can increase within a population over time if the trait continues to provide better fitness
what is a pathogen
an infectious agent that can produce a disease that can evolve and cause emergent diseases
what affect do pathogens have on diversity
pathogenic genomes experience high mutation rates which generates increased diversity
what is the relationship between pathogens and the host
༻ chemically compatible with the host
༻ they coevolve with the host
༻ the presence of pathogens can change the phenotypes selected for/against in the host population
what are some examples of pathogens evolving and causing emergent diseases
༻ 2009 Swine Flu Pandemic
༻ COVID-19 Pandemic
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