Chapter 16 Flashcards
phylogeny
evolutionary history of relationships between organisms
phylogenetic tree
diagrammatic reconstruction of phylogeny
lineage
series of ancestor and descendant populations
node
split in the phylogenetic tree when an ancestral population divides into two non-interacting descendant populations
root
common ancestor of all organisms in the tree
taxon
any group of species that we designate with a name
clade
taxon that consists of all the evolutionary descendants of a common ancestor
sister species
two species that are each other’s closest relatives
sister clades
two clades that are each other’s closest relatives
systematics
the study and classification of biodiversity
homologous
features shared by two or more species that have been inherited by a common ancestor
ancestral trait
a condition that other traits can evolve from
derived trait
the trait that comes from the ancestral trait
synapomorphies
derived traits that are also evidence of the common ancestry of a group of organisms
convergent evolution
similar traits may evolve independently in different lineages
evolutionary reversal
a character may revert from a derived state back to an ancestral state
homoplasies
similar traits generated by convergent evolution and evolutionary reversals
ingroup
group of organisms of primary interest in a phylogenetic study
outgroup
species or group closely related to the ingroup but known to be outside of it
parsimony principle
preferred explanation of observed data is the simplest one
what are methods for reconstructing phylogenies?
morphology, development, palaeontology, behaviour, molecular data
morphology
presence, size, shape, and other attributes of body parts
how does development reveal evolutionary relationships?
some organisms exhibit similarities in early development stages only
how does palaeontology reveal evolutionary relationships?
fossils provide important evidence that helps distinguish ancestral from derived traits
behaviour
some behavioural traits are culturally transmitted and others are genetically inherited
molecular clock
rates of molecular change are constant enough that they can be used to predict evolutionary divergence times
binomical nomenclature
system of naming organisms
what are the two components of a scientific name?
genus name and then species
what formatting is used in a scientific name?
italics
which letters in a scientific name are capitalised?
the first letter of the genus name
what is the order of all the classifications, from most general to most specific?
kingdom, phylum, class, order, family, genus, species
polyphyletic
a group that does not include its common ancestor
paraphyletic
a group that does not include all the descendants of a common ancestor
monophyletic
taxon contains and ancestor and all descendants of that ancestor, and no other organisms
