Tree of life #17 Flashcards
What do phylogenies show?
Phylogenies show the evolutionary relationships among organisms based on their shared ancestry.
What is the importance of phylogenies?
Phylogenies are important in discovering genes and understanding similarities and differences in traits among organisms.
What is LUCA?
LUCA stands for Last Universal Common Ancestor, and is estimated to have lived around 4-3.7 billion years ago.
What does the Tree of Life represent?
The Tree of Life represents the evolutionary relationships among all living organisms, with closely adjacent twigs representing living species that are derived recently from their common ancestors.
Why do some groups of organisms have many species while others have few?
Diversification within groups is uneven, with some groups having many species due to different adaptive radiations and chance.
Can genes be replaced between different organisms?
Yes, almost half of the 414 genes necessary for yeast survival could be replaced with equivalent human genes.
What can phylogenetics be used to classify organisms into?
Phylogenetics can be used to classify organisms into monophyletic (ancestor and all descendants) and paraphyletic (ancestor and some, but not all, descendants) groups.
What information can genealogical classification convey?
Genealogical classification can convey information about relationships among organisms, as well as their genetic and ecological similarities and differences.
What is the molecular clock hypothesis?
The molecular clock hypothesis assumes that DNA differences accrue linearly with time, and can be used to estimate the time of divergence between lineages.
What can phylogenetic analyses help to match?
Phylogenetic analyses can help to match colonization events to determine the history of species dispersal.
What can phylogenies be used to infer?
Phylogenies can be used to infer the characteristics of ancestral species based on the characteristics of their descendants.
What is the comparative method?
The comparative method involves comparing sets of species to test hypotheses about adaptations.
What is homoplasy?
Homoplasy (convergent evolution) is common, where independent evolution of characters occurs in different lineages.
What is Dollo’s law?
Dollo’s law suggests that once lost, characters are unlikely to be regained.
What is mosaic evolution?
Mosaic evolution is a pattern where different characters evolve at different rates within a lineage.
