lecture 5

Question 1

systematics

Answer 1

study of biological diversity and its origins and evolutionary relationships among organisms and their traits, ecology, and geographic distributions.

Question 2

taxonomy

Answer 2

theory and practice of describing, identifying, naming, and classifying organisms.

Question 3

nomenclature

Answer 3

set of rules governing taxonomic practice

Question 4

classification

Answer 4

hierarchical scheme for arranging or organizing nomenclatural rules

Question 5

taxon

Answer 5

basic unit of systematics; can refer to any named groups of organisms. provides universal vocabulary of names for distinct organisms

Question 6

taxa

Answer 6

plural of taxon

Question 7

Tuatura (Sphenodon photatus)

Answer 7

l- ast survivor of the order Rhynchocephalia, isolated on New Zealand for 82 mil yrs, legislation to protect species, but not all pops (40 islands, 25% extinct); failure to recognize distinct species; already one known extinction

• MCH diversity has adaptive significance for pathogen resistance.
• Tuatara pops. are highly differentiated.
• pop on North Brothers island is a distinct species of Spheodon guntheri (~350 left).

Question 8

Describing new species

Answer 8

• 2 mill species are described

- about 8 mill left to be discovered and described

Question 9

Describing new species requires a lot of work

Answer 9

1. description and diagnosis must be adequately published in widely accessible form
2. criteria of availability: name must be available
3. validity of name: principle of priority, not already in use
4. bionominal form in latin or greek (Genus species (italic (or underline)).
5. law of type fixation: designated type specimen, name bearer

Question 10

Species description ex

Answer 10

New combination (name of species in italics) sp. nov. (bold)

• holotype:
• paratype:
• diagnosis:
• desc of holotype:
• coloration of holotype:
• variation:
• etymology:
• distribution & ecology:
• remarks:

Question 11

type specimens

Answer 11

• provide a physical reference point for a named taxonomic unit; are not typical representatives of a species
• provide a historical reference point for a species diagnosis

Question 12

holotype

Answer 12

single physical example of an organisms used to formally describe a species

Question 13

paratype

Answer 13

additional specimens other than the holotype, listed in the type series, where the original description designated a holotype.

Question 14

neotype

Answer 14

a specimen later selected to serve as the single type specimen when the original holotype was lost or destroyed or never designated.

Question 15

why do species matter?

Answer 15

• research in specimens in museum collections represent evidence and data for investigating biodiversity
• specimens document variation with species, distributions (current and historical), seasonal patterns, age differences, etc.
• collections based museum research is the primary driver of all phylogenetic and systematic work
• Specimens contain sources of data that are not apparent to us today, but will be of crucial importance in the future.

Question 16

Authorities for naming new taxa

Answer 16

• responsible for providing and regulating nomenclature systems.
• promote stability and universality in the scientific names of animals and to ensure that the name of each taxon is unique and distinct (stable taxonomy = useful taxonomy; traceable and documented history of names)

Question 17

Carl Linnaeus

Answer 17

• 1748; published Systema naturae, his classification of all plants and animals known at the time.
• classification based on a progressive subdivision of groups based on overall similarities and differences
• many features of his system are still used today (taxonomic ranks)

Question 18

Problems with ranked classification

Answer 18

• typological - impossible to describe all genetic and morphological diversity of a species with a single specimen or a type species (paratypes)
• ranks - impossible to provide enough ranks to describe all evolutionary relationships

Question 19

Ranks promote misguided biological comparisons

Answer 19

• comparisons have no phylogenetic basis
• no correspondence to age of group
• paraphyletic group - a group that includes a common ancestor and only some of the descendants of that ancestor (living and extinct)
• ranks are arbitrary and subjective

Question 20

Rank free classification

Answer 20

• phylocode - rules governing phylogenetic nomenclature. it is designed to name parts of the tree of life by explicit reference to the phylogeny.
• the phylocode will only allow the naming of the clades, not of paraphyletic or polyphyletic groups.
• only species and clades have names; all ranks above species are excluded from the nomenclature.
• only allows the use of specimens, species, and apormorphies as specifiers (anchors)
• can be used concurrently with the existing codes based on rank-based nomenclature (ICBN, ICZN, etc)

Question 21

Rank free classification: node based

Answer 21

the clade originating with the most recent common ancestor of A and B

Question 22

Rank free classification: branch based

Answer 22

the clade that consists of A and all species that share a more recent common ancestor with A than C

Question 23

Rank free classification: apomorphy based

Answer 23

the clade originating with the first species to possess apomorphy X as inherited by A and B.