Science 1.3 "What Is Phylogenetics?"

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systematics

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20 Terms

systematics

scientists use the term to refer to the line classification system in use today

<p>scientists use the term to refer to the line classification system in use today</p>

phylogenetic analysis

-the process of grouping organisms based on multiple shared characteristics (characters) or traits that weren't shared w/ organisms that were thought to have been their ancestors -it is based on assumptions that evolution has occured

phylogenetic tree

-a branching diagram that resembles a tree -the result of the phylogenetic analysis process -evolutionary scientists use it to show the relations between organisms

<p>-a branching diagram that resembles a tree -the result of the phylogenetic analysis process -evolutionary scientists use it to show the relations between organisms</p>

cladogram

-term is synonymous w/ "phylogenetic tree" -it's a branching diagram that shows the relationships, similarities, + differences between organisms

<p>-term is synonymous w/ &quot;phylogenetic tree&quot; -it&apos;s a branching diagram that shows the relationships, similarities, + differences between organisms</p>

parsimony

term that describes when scientists select the simplest option, or the one that requires the fewest evolutionary changes when decididng which (phylogenetic) tree to choose

cladistics

-another name for the process of phylogenetic analysis -it's a system of classification based on phylogenetics -it answers what animals are most closely related to each other -doesn’t answer if organisms evolved cause it assumed that evolution happened

early years of classification

-first studied in 1700s by Carolyn’s Linneaus -organisms were places in groups w/ obvious characteristics

microscopes and tools

things used by scientists to look at an organism's cell structure + DNA

three domains of life

-Archae, Bacteria, + Eukarya -these were found by discoveries using molecular analysis

assumption

-a statement that's assumed to be true even though it can't be proved -second way of classificaion -it is accepted by taxonomists

taxonomist work foundation

looking for evidence of assumptions that organisms evolved from common ancestors

three conclusions from the phylogenetic tree

-scientists' conlusion -evolutionists' conclusion -creationists' conclusion

scientist conclusion

infers that salamanders share more characters (characteristics) w/ the lizard than w/ the chimpanzee

evolutionist conclusion

infers that shared characters result from a shared evolutionary history

creationist conclusion

the phylogenetic tree simply shows which organisms are designed to be more similar + which traits are shared by multiple creatures

4 steps to study living

-used by scientists

  1. collect data about specific traits that similar organisms have

  2. collected data is entered into a computer database

  3. computer data base analyzes the data + looks for similarities + generates phylogenetic trees

  4. if scientists encounter conflicting data in phylogenetic analysis, they must choose which (simplest) tree to choose = parsimony

clades

groups of animals that share similar characteristics + are nested within larger ones

<p>groups of animals that share similar characteristics + are nested within larger ones</p>

archae

archaebacteria

bacteria

eubacteria

eukarya

protists, fungi, plantae, animalia