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Outline: The role and value of Systematics

Taxonomy (α taxonomy) - in decline? Describing species Identification, Classification Collections, Conservation Phylogenetics (β taxonomy) Phylogeny Classification (?) Evolutionary processes / patterns Conservation

Lecture 1: Introduction to biological systematics (value)

Mayr, E.& P. D. Ashlock (1991) Principles of Systematic Zoology, 2nd Edition, McGraw-Hill, Inc., NY. pp. 1-8. [PDF]

*Godfray, H. C. J. (2002) Challenges for taxonomy. Nature 417: 17-19.

Flowers et al. (2002) Does the decline in systematic biology matter? Chapter 4 of report to the House of Lords (UK). Select Committee on Science & Technology. [webpage]

Lecture 2: Value of biosystematics continued; History of taxonomy

*Gould, S. J. 2000. Linnaeus's Luck? Natural History. Vol 109 iss.7 : (September): 19-25, 66-76.

Mayr, E.& P. D. Ashlock (1991) Principles of Systematic Zoology, 2nd Edition, McGraw-Hill, Inc., NY. pp. 9-18. [PDF - see link under lecture 1]

•  alpha taxonomy / phylogenetics (descriptive taxonomy / phylogenetic tax.)

- suffering from lack of prestige & resources

•  Solutions?

•  “web monographs” ?

•  unitary taxonomy ?

Godfray (2002)

“Descriptive” taxonomy -  Describing -  Cataloging -  Classifying -  Stamp collecting?

Hypothetico-deductive taxonomy - Descriptions based on theory & hypotheses - Seek a ‘natural’ classification

Gould - Linnaeus’s Luck

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“Systematic biology has contracted at British universities to such an extent that it may be in danger of extinction as a sustainable discipline.”

- 1992 the Dainton Report on Systematics in the UK

α (alpha) taxonomy

Demographic trends in alpha taxonomy:

1990 survey

63% of taxonomists > 46 years old

Only 8% < 35 years old

α (alpha) taxonomy

“If we found these demographic trends in a newly discovered species of lemur, we would bring

specimens into a zoo and start a programme of captive breeding.

But if these trends continue among taxonomists and systematists, how soon will it be before we cannot

recognize a new species of lemur?”

Gaston, K. J. and R. M. May. 1992. Taxonomy of taxonomists. Nature 356: 281-28

α (alpha) taxonomy

Systematics training in universities -

- molecular systematics (your text)

- phylogenetics

- rarely any training in alpha taxonomy

- knowledge & skills are being lost

α (alpha) taxonomy

Results of this decline -

- systematists who can’t do identifications

- orphaned taxa

- fewer people to describe species

- lots of new trees, but fewer taxonomic changes

α (alpha) taxonomy

Results of this decline -

- systematists who can’t do identifications

- orphaned taxa

- fewer people to describe species

- lots of new trees, but fewer taxonomic changes

“We sit on the brink of a crisis”

Not enough trained taxonomists to describe remaining 5-15 million species - even if we had the money

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Solutions -

- Modernization - new technology

- digitization, web-publication, DNA

- NSF PEET grants (Partnership for Enhancing Expertise in Taxonomy)

α (alpha) taxonomy

descriptions

identification

collections classification

character evolution

phylogeny

biogeography

Systematics

Standard:

“Activity of grouping entities or phenomena and giving names to the resulting groups”

-Wiley (1981) p. 194

Classification - usage of term

Actual usage today:

“Activity of grouping entities or phenomena and giving names to the resulting groups”

Classification - usage of term

Phylogenetic analysis

Classification

- Not ‘identification’

-  Not phylogenetic analysis -  often used as such (e.g. “3 schools of classification”)

-  implications are wrong

-  Not a phylogeny -  often thought that “tree = classification” -  many students misunderstand this

Classification - usage of term

So what is it?

-  is an arrangement of names - names for groups (of names…)

-  Linnaeus prepared classifications

-  many modern phylogeneticists do not - new trees are not new classifications - new classifications can be based on new

trees however

Classification - usage of term

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Phylum Annelida Class Polychaeta Family Siboglinidae Class Clitellata Subclass Oligochaeta Subclass Hirudinea Class Echiura

Phylum Sipuncula

We’ll do more on classifications and trees later

Example Classification Trees Classification

= Names

Giribet et al Nature 2001

1. Provide Classifications for our millions of species

Provide natural classifications = reflect evolutionary history = based on sound phylogenetic analyses

Natural classifications allow predictions

Systematics - value

Allow prediction of attributes of taxa not yet studied

- medicines (antibiotics, etc.) - biological control agents - predict ecological relationships - extinct taxa - singing dinosaurs?

Systematics - value

Bad, “unnatural” classifications can be disastrous

e.g. Gypsy moth - brought to Boston by a frenchman, Leopold Trouvelot - hoped to start a business in silk - chose this moth because of its name at

that time: Bombyx dispar - oriental silk moth = Bombyx mori

Systematics - value

Moth was no good for silk

Was very good at eating native trees

Escaped & is still a major pest species

Current name: Lymantria dispar (different superfamily from Bombyx !)

Systematics - value

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Tuatara - Sphenodon © Frans Lanting 2002

Only surviving genus of an ORDER of Reptiles

(Bad) Taxonomy used for conservation assumed 1 species when there were 2+

Resulted in - possible extinction of a subspecies - near extinction of a second species (extinction of 10 of 40 populations)

Described in Nature: 347, 177-179 (1990)

Systematics - value

2. Infer phylogenies - inform our classifications - to know what a organism “is” requires

phylogeny e.g. tongue worms - pentastomids

bizarre parasites of vertebrates - what are they?

Systematics - value

Classified in their own phylum

Only in last few decades have we determined they are Arthropods specifically Maxillopod Crustaceans!

Systematics - value

3. Understanding evolutionary processes a tree is required to study: - Cospeciation - Historical biogeography, phylogeography - Macroevolutionary patterns explosive radiations extinctions - Trait correlations Are warning colors related to the evolution of

gregariousness? - Adaptations

Systematics - value

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•  Both derived from outpocketings of the gut •  Both structures hold gas

– Swim bladders to adjust buoyancy – Lungs for gas exchange

•  Tetrapods & some fish have lungs •  Many fish have swim bladders

Which is the came first? Need a tree…

Evolution of Swim Bladders & Lungs

Sound natural classifications or phylogenies enable biologists to

•  intelligently frame their hypotheses

•  understand the direction of evolutionary change

•  know which taxa are appropriate for comparative studies

Systematics - value

Human population growth (~7 billion currently)

~ 972 million in high income countries

~ 5.4 billion in middle & low income countries

[high income countries use twice the resources of the middle & low income countries]

Mann, M.E., Ammann, C.M., Bradley, R.S., Briffa, K.R., Crowley, T.J., Hughes, M.K., Jones, P.D., Oppenheimer, M., Osborn, T.J., Overpeck, J.T., Rutherford, S., Trenberth, K.E., Wigley, T.M.L., 2003. On Past Temperatures and Anomalous Late 20th Century Warmth. Eos 84, 256-258

Global Warming - ~0.8°C so far; target <2°C (if we burn 565 Gigatons of CO2), but plans are set to burn 2,795 Gigatons...

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Global Warming

Deforestation - habitat destruction >50% of species live in rain forests ~2% of these forests disappear each year e.g. Ghana -1990 and 2005, Ghana lost 25.9%

Relationship between rural population density and remaining closed-canopy forest [(current forest area/estimated original forest area) × 100] for 45 tropical nations in Africa (circles), the Americas (squares) and Asia (diamonds). Adapted with permission from S.J. Wright and H.C. Muller-Landau, The future of tropical forest species, Biotropica 38 (2006), pp. 287–301.

Conservation Biology - Biodiversity crisis

- Massive habitat destruction

- ca. 1 species extinction / 20 minutes (26k/yr) CENTINELAN EXTINCTION = named for Centinela Ridge in Ecuador Gentry & Dodson, 1978, 90 new species endemic to ridge, 8 yrs later destroyed

for a plantation - current extinction rates 100 to 1,000 times

greater than “normal”, Earth’s 6th mass extinction? (Barnosky et al 2011 Nature)

Systematics - value

Conservation Biology - Biodiversity crisis

Phylogenies help identify unique lineages

e.g. “living fossils”

e.g. a duckbilled platypus

Systematics - value

Systematics "is at the same time the most elementary and most inclusive part of biology, most elementary because organisms cannot be discussed or treated in a scientific way until some taxonomy has been achieved, and most inclusive because systematics in its various branches gathers together, utilizes, summarizes, and implements, everything that is known about organisms, whether morphological, physiological, or ecological.”

Paraphrased from George Gaylord Simpson's book, “Animal Taxonomy”

Systematics

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History of Taxonomy

Aristotle

384-322 B.C.

Father of Biological Classification

Used concept of nested sets

Named various taxa e.g. Coleoptera

“Sheath-wing” Oldest scientific names still in

use

Phylum Annelida

Class Polychaeta

Class Clitellata

Class Echiura

Subclass Oligochaeta

Subclass Hirudinea

Nested Sets

History of Taxonomy

Botanical taxonomy developed faster than zoological

Plants used for medicines & foods

Theophrastes 371-287 B.C. - classified 500 species of plants (e.g. Asparagus)

Books on plants (herbals) with illustrations, descriptions & names became common

History of Taxonomy

Herbals copied without improvements throughout the Middle Ages

Very little progress until the 15th century - Gutenberg’s printing press

Botanists began using phrase names - descriptive names of species

Latin, usually < 12 words

History of Taxonomy

Phrase names: Joseph Pitton de Tournefort - paved the

way for Linnaeus

Key work published in 1700 instituted the genus name

e.g. Mentha floribus spicatis, foliis oblongis serratis

“mint with flowers in a spike, leaves oblong and toothed”

History of Taxonomy

First Bioinformatics crisis - too many new species & names, chaos reigned

Linnaeus instituted a simpler, more organized system - binominal nomenclature, 1753, [6,000 plants]

based on binomen - species name composed of two words - as an abbreviation for the full phrase names

(note: not binomial nomenclature)

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History of Taxonomy

The binominal system was actually first used by Gaspard Bauhin (1623) but never caught on

Linnaeus reintroduced & imposed it on the world - chaos was averted

Zoological nomenclature began with the 10th edition of Linnaeus’s Systema Naturae (1758) - why this edition?

History of Taxonomy

Linnaeus’s 5 ranks:

Kingdom - Animalia Class - Insecta Order - Coleoptera Genus - Silpha Species - Silpha vespillo

All animals in 312 genera

Describe the decline of alpha taxonomy & ideas to reverse it

Understand the term Classification (not easy!)

Describe the value of phylogenetics

Describe the key people & their influence on the development of Systematics

You should be able to