Evolution Flashcards
what are the two dating methods used to determine the age of a fossil?
relative dating - determines whether a fossil is older or younger than other fossils
radiometric dating - relies on radioactive isotopes, which decay, or break down, into stable isotopes at a steady rate
what is evolution?
change over time ; the process by which modern organisms have descended from ancient organisms
how old have scientists determined the Earth to be?
4.2 billion years
when did life first appear on Earth?
3.7 billion years ago
what were the first life forms?
unicellular, prokaryotic
list the following in the order in which they appeared over earth’s history: eukaryotes, prokaryotes, multicellar organisms
prokaryotes , eukaryotes , multicellular organisms
what evolutionary event does the endosymbiotic hypothesis explain?
it says that prokaryotic cells entered those ancestory eukaryotes
list the evidence for the endosymbiotic hypothesis
mitochondria and chloroplasts contain dna similar to bacterial dna
what is the goal of systematics or classification?
to organize living things into groups that have biological meaning
what is a cladogram and how can it be used to classify organisms?
it links groups of organisms by showing how evolutionary lines, or lineages branched off from common ancestors
- how closely related they are
how can a cladogram be used to determine similarities in DNA sequences and recent common ancestry?
if they are closer together on the cladogram they are more related and have a more recent common ancestor
what is a derived character?
a trait that arose in the most recent common ancestor of a particular lineage and was passed along to its decendants
what does a node on a cladogram represent?
the common ancestor
what scientist incorrectly thought thst evolution could be explained by the inheritance of aquired traits? what does the inheritance if aquired traits mean?
lamarck
traits altered by an individual organism during its life
who developed the theory that evolution occurs by the process of natural selection?
charles darwin
what is natural selection?
process by which organisms that are most suited to their enviroment survive and reproduce most successfully
list four components of the natural selection theory
struggle for existance
variation
adaptation
survival of the fittest
how do adaptations such as camouflage and mimicry develop?
nature provides
how does the variation needed for natural selection arise?
some variations are better suited to life in their enviroments than others
what is a gene pool?
consists of all the genes including all the different alleles for each gene
how do u know if a population is evolving in terms of allelic frequencies?
allele frequency is changing
what is happening to allelic frequencies in a population that js in genetic equilibrium?
its staying the same
list five factora that cause allelic frequencies to change in a population
small population, migration, natural selection, random mating, mutations
list four major classes of evidences for evolution
fossil records
comparing of analogy , embryos , & dna
