Chapter 26

is evolutionary history of species or group of related species; provides important information on similar characteristics in closely related species; was used to identify species of whale from which 'whale meat' originated; bracketing allows people to predict features of ancestor from features of its descendants; analysis shows HIV is descended from viruses that infect chimpanzees and other primates.

is discipline that classifies organisms and determines their evolutionary relationships.

is scientific discipline concerned with classifying and naming organisms.

published system of taxonomy based on resemblances in 18th century.

include two part names for species and hierarchical classification that remain useful today.

is two part species scientific name.

is first part of name.

is second part that is unique for each species within genus.

is system Linnaeus introduced for grouping species in higher inclusive categories.

from broad to narrow include: 1)domain 2)kingdom 3)phylum 4)class 5)order 6)family 7)genus 8)species

is taxonomic unit at any level of hierarchy.

is evolutionary history of group of organisms; represents hypothesis about evolutionary relationships; for best hypothesis fit most data (morphological, molecular, and fossil).

and phylogeny can differ from each other.

have proposed classification system that would recognize only groups that include common ancestors and all its descendants; get information about morphologies, genes, biochemistry of living organisms; need to distinguish whether similarity is homology or analogy when making phylogeny; use computer programs, math tools when analyzing comparable DNA segments from different organisms; can never be sure of finding best tree in large data sheet; narrow options by applying max parismony and max likelihood.

represents divergence of 2 species.

are groups that share immediate common ancestor.

includes branch to represent last common ancestor of all taxa in tree.

diverges early in history of group and originates near common ancestor of group.

is branch which more than two groups emerge.

show patterns of descent (not phenotypic similarity); do not indicate when species evolved or how much change occurred in lineage.

are inferred from morphological and molecular data.

is similarity due to shared ancestry (Ex: bat and bird wings [fare limbs]).

is similarity due to convergent evolution. (Ex: bats and birds [functions of wings])

are analogous structures or molecular sequences that evolved independently; molecules are identified by math tools.

elements are more likely when they are similar in two complex structures; characters can be used to infer phylogeny once they have been identified.

is important when distinguishing homology from analogy.

are used to construct phylogenetic trees; along with different characteristics are in comparison for an organism with its ancestor; can be both ancestral and derived (depending on context).

group organisms by common descent.

is species group that includes ancestral species and all its descendants; a shared character first appeared in is useful to know when inferring to evolutionary relationships.

is valid clade signifying that is has ancestor species and all its descendants.

is grouping that consists of ancestral species and some descendants.

is grouping that has distantly related species but does not include their most recent common ancestor; groups are distinguished from paraphyletic groups since they do not include most recent common ancestor.

is character that originated in an ancestor of taxon; are characters shared by out-group and in-group that predate divergence of both groups from common ancestor.

is evolutionary novelty unique to particular clade.

is species or group of species that is closely related to in-group; is group diverged before in-group; are used by systematics to differentiate between shared derived, and shared ancestral characteristics.

is various species being studied.

can reflect on number of genetic changes that have been taken place in certain DNA sequence in that lineage; can represent chronological time, can be determined from fossil record.

assumes that tree that requires fewest evolutionary events is most likely.

is principle that states that tree can be found that reflects most likely sequence of evolutionary events given certain rules about how DNA changes overtime.

is where an organism's evolutionary history is documented

from hundreds of millions of years ago can be useful when DNA that codes for r-RNA changes relatively slowly.

evolves rapidly and can be used to explore recent evolutionary events.

increases number of genes in genome (providing more opportunities for evolutionary changes); result in gene families; can be traced to common ancestor like homologous genes.

is homology that results from speciation event and occurs between genes found in different species; are widespread and extend across many widely varied species (Ex: humans, mice diverged about 65 million years ago, 99% of human genes are orthologous); has nucleotides substitutions that are assumed to be proportional to time since they last shared common ancestor.

are orthologous genes.

result from gene duplication (multiple copies of these genes; can diverge within clade that carries them and often evolve new functions; has nucleotides substitutions that are proportional to time since genes became duplicated.

help track evolutionary time; uses constant rates of evolution in some genes to estimate absolute time of evolutionary change; are calibrated against branches whose dates are known from fossil record; does not run as smoothly as expected if mutations were neutral; application of HIV suggests that that strain spread to humans during 1930s; more advanced approach estimated first spread to humans around 1910.

understanding continues to change based on new data; branches have had insight from people through molecular systematics lately; suggests eukaryotes and archaea are more closely related to each other than to bacteria; is based largely on r-RNA genes (some other genes reveal different relationships).

Monera (prokaryotes), protista, plantae, fungi, animalia

Bacteria, archaea, eukarya

is movement from one genome to another; occurs by exchange of transposable elements, plasmids, viral infection, and organisms fusion; occurrence is result of disparities between gene trees; has played key role in evolution of both prokaryotes and eukaryotes; is argued by some biologists to be so common that early history of life should be represented as tangled network of connected branches.