4.2 Evolution - studying & evidence Flashcards
what sources can scientists use to study evolution?
palaeontology
comparative anatomy
comparative biochemistry
(palaeontology) what is palaeontology?
study of fossils and the fossil record
(palaeontology) what are fossils? when are they formed?
plant and animal remains preserved over long periods of time
formed in absence of microbes
(palaeontology) fossils allow what to be investigated?
relationships between extinct and extant organisms
(palaeontology) studying similarities in fossil anatomy scientists can see how closely related what?
organisms are to each other and the same ancestor
(palaeontology) where are fossils of simplest organisms found?
older rocks
(palaeontology) where are fossils of more complex organisms found?
more recent rocks
(palaeontology) the finding of simpler organisms in older rocks supports what theory?
complex organisms evolved from simpler organisms
(palaeontology) plant fossils appear before animals consistent with what fact?
animals need plants to survive
(comparative anatomy) the study of what?
similarities and differences in the anatomy of living organisms
(comparative anatomy) why is anatomy used as evidence of evolutionary relationships?
the fossil record is incomplete
(comparative anatomy) what structures can be looked at?
homologous structures
(comparative anatomy) what are homologous structures?
structures appearing differently in all organisms with the same basic structure
(comparative anatomy) give an example of a homologous structure:
pentadactyl limb of vertebrates
they have similar structures despite different functions e.g. running, flying, jumping
(comparative anatomy) homologous structures give evidence of what type of evolution?
divergent evolution - how different species evolved from a common ancestor
(comparative biochemistry) is the study of what?
similarities and differences in the chemical makeup of organisms
(comparative biochemistry) studying the genetic code of organisms gives evidence of what?
life evolving from a common ancestor
(comparative biochemistry) although molecules change overtime what happens to the important ones?
they are conserved
(comparative biochemistry) slight changes in important molecules can help what?
determine evolutionary links
(comparative biochemistry) what two important biomolecules are studied?
cytochrome c
ribosomal RNA
(comparative biochemistry) the information gained can help determine what?
how long ago species shared a common ancestor
(evidence) what is DNA hybridisation?
single strand of DNA from one species is mixed with a single strand of DNA from another
the more bases that match up the closer related the species
(evidence) how does DNA hybridisation provide evidence of evolution?
proves similarities between organisms e.g. Darwins out of Africa theory - that humans evolved from apes in Africa
(evidence) how is DNA profiling used to study evolution?
used to study mutation enzymes will cut the base sequences differently if the sequence has changed
(evidence) how does DNA profiling provide evidence of evolution?
provides evidence of genetic differences between species
(evidence) what do DNA molecular clocks use?
PCR and DNA sequencing to allow rapid determination of DNA bases
(evidence) how do DNA molecular clocks provide evidence of evolution?
compare species and see how long ago they shared a common ancestor - used to construct evolutionary trees
(evidence) what is DNA and Protein sequencing?
comparing base sequences of DNA and amino acids of different species
(evidence) how do DNA and protein sequencing provide evidence of evolution?
show which organisms evolved from a common ancestor and how recently
