Phylogeny Flashcards
why do scientists study organism’s DNA, proteins, and the fossil record?
to discover links between organisms and common ancestors.
what is phylogeny?
the name given to the evolutionary relationships between organisms .
what is phylogenetics?
the study of the evolutionary history of groups of organisms.
what does phylogentics allow scientists to find?
phlogeny reveals which group a particular organism is related to, and how closely related these organisms are.
what is a phylogenetic tree?
a diagram used to represent the evolutionary relationships between organisms. they are branched diagrams, which show that different species have evolved from a common ancestor.
what is the structure of a pylogenetic tree?
the earliest species is found at the base of the tree and the most recent species are found at the tips of branches.
how are phylogentic trees produced?
by looking at similarities and differences in species’ physical charcteristics and genetic makeup. much of the evidence has been gained from fossils.
what do the tips of phylogenetic trees represent?
groups of descendent organisms.
what do the nodes of the phylogenetic tree represent?
the common ancestors of those descendants.
what are sister groups?
two descendents that split from the same node.
what are the advantages of phylogenetic classification?
- confirms the classification of an animal despite physical appearance
- phylogeny produces a continuous tree whereas classification requires discrete taxonomical groups. As a result, scientists are not forced to put organisms into a specific group that they do not quite fit.
- the hierachial nature of LInnean classification can be misleading as it implies different groups within the same rank are equivalent. For example, the cats and the orchids are both families. However, the two groups are not comparable - one has a longer history than the other.
