Study of evolution
is exciting; study of taxonomy is dull (or worse)
"I look at the term species, as one arbitrarily given for
the sake of convenience
to a set of individuals closely resembling each other...." (Darwin,
1859)
The undergraduate species concept:
"Why can't y'all just pick one name so I can memorize it and forget it?"
(A&M student, 1984)
A modern view: Systematics
(the science of naming organisms) is dynamic
Taxonomy is based on hypotheses
of relationship:
"A & B
are more closely related to each other than either is to C"
Relationships are simple: patterns of common ancestry
Natural Classification will reflect these relationships (phylogeny)
Nomenclature (scientific names) changes when hypotheses
are modified
How it Works : "Helix & Primer" DNA Sequencing Service
Molecules provide large data sets:
Homo has 2 x 102 bones versus 3 x 10
nucleotide pairs
Different genes provide complementary insights:
maternal mtDNA vs paternal
Y-DNA
[except sometimes: sexing birds]
Rules
of molecular evolution are understood:
Ts vs Tv / silent
vs
substitution / 3rd
vs
1st & 2nd
Methods of Phylogeny Reconstruction
are robust
Molecules provide independent estimates of phylogeny
Avoids a circular argument:
Morphology, behaviour, and/or biogeography create classification,
classification explains evolution of morphology etc.
Morphological
evolution of antlers in New World Deer (Cervidae)
All deer have antlers
except Chinese water deer (Hydropotes)
=> a separate subfamily (Hydropotinae) & the ancestral type
But: Molecular analysis shows Hydropotes antlers lost secondarily
=> part of the New World subfamily (Odocoileinae)
Antlers started big, got smaller
Neotropical deer are an independent
radiation
"Spike antlers" are consequences
of allometry
Breeding
behaviour in seals of the North Atlantic (Phocidae)
Origins of substrate usage in pagophilic-
vs
terrestrial-breeding species
"Type" Harbour Seal (Phoca
vitulina Linnaeus, 1758) breeds on land
"Greenland" Harp Seal (Phoca
groenlandica) breeds on ice: Why?
But: Molecular analysis shows that Harps & Hooded
Seals (Cystophora) are close relatives
Harp seal = Pagophilus groenlandicus
=> Pagophilic breeding is ancestral
Biogeographic
origins of Pacific codfish (Gadidae)
All cod, haddock, & pollock
were originally Gadus L., 1758
Molecular analysis shows Pacific
endemics are independent invasions
Tomcod (Micgrogadus spp.) includes Saffron
Cod & Navaga (Eleginus spp)
Pacific Cod (Gadus macrocephalus) includes Greenland
Cod
Alaska Pollock (Theragra chalcogramma) = G.
chalcogrammus ? (Work in Progress)
Genomics: the study of complete gene sets
Marine
Mitochondrial Genomics
A whole-genome approach to population biology & systematics
with special reference to fisheries
High-Resolution & Statistical confidence
The "Out
of Africa" hypothesis of human origins
(Ingman et al. 2000)
Origins of first settlers of Newfoundland (Pope, Marshall, & Carr 2004)
The "Out of Newfoundland"
hypothesis of harp seal origins
(Work in Progress)
Evolution of Phocid Seals
Harp Seal population genomic
structure
How to tell a Sea Monster: identifying the Fortune Bay "sea monster"