BIOS1200: Biological Diversity

Over two semesters: Semester 1: Inverts Fish Semester 2: Tetrapods

Handbook – course information

Module leader

Module lead (i.e. who you should contact with problems/questions)

Semester 1:Dr Chris Brown

Chris.brown@worc.ac.uk

Tutors – Semester 1

Dr Chris BrownAreas of expertise:Bird and mammalian physiological ecologyChris.Brown@worc.ac.uk

Dr Sue BrownAreas of expertise:Rare and threatened species and habitatsSue.Brown@worc.ac.uk

• When and where?• All teaching sessions will be held on

Thursday mornings. They start promptly at 09.15 am,

• Room EE G055 (ground floor along from main reception)

• What? • Clue – course is called Animal Diversity.

See indicative scheduleOver two semesters:

Semester 1: Invertebrates Fish Semester 2: Tetrapods

TimetablesNote: PracticalsBring your lab coat just in case. All sessions are four hours.

Sessions may include seminars, case studies and discussions.

TimetablesAttend all sessions. Supporting material is on Blackboard BUT is difficult to follow if you haven’t been present. E-mail session tutor if you are absent.

If you do not attend a mandatory session you need to claim for mitigating circumstances in order not to be capped at a D- for the relevant assessment.

Assessments and feedbackAssessmentTest your knowledge of the subject in a variety of formats. Why?

Assessments and feedbackTest your knowledge in a variety of formats: • Semester 1:

– 001 Practical report (25%)– 002 End of semester exam (25%)

• Semester 2: – 003 Practical file (25%)– 004 End of semester exam (25%)

Details in module handbook. You will be given further guidance, chances to consult your tutors and support on Blackboard. .

Assessments and feedbackCheck e-mail and Blackboard regularly for updates

as this is the only way module leaders and tutors have to communicate any important information Other resources to help.Study Skills Sessions on Friday lunchtimes. GO TO THESE. • Library

• Student support services have generalised help as well as support for dyslexia. Make use of the services that are available to you

BlackboardLinks to pdf

For communications betweenyou and us and for us to remindyou about deadlines etc…

Material for lectures will be put up at least a day in advance.

This will:- allow you to print out notes IF you want.- give opportunity to study subject before you come.

Blackboard

BlackboardThis will: - NOT substitute for being in sessions. Lectures are

only part of the course. Discussion groups & practicals will contribute to your learning too.

Lectures and extra reading- Lectures and taught sessions act as jumping-off

points. They are not all you need to learn. - We expect you to use them to start to identify

your interests & follow them up via extra reading

• You should take your own notes.• only YOU know what will act as a memory prompt for you

• We know that students that take notes do better.

• Note-taking guides also available in General resources folder in Module Information on Blackboard .

Taking notes

From now on…- Inspiration & support is our responsibility

- Learning is your responsibility

I like to think about what I

read

An Introduction to Animal Diversity

BIOS1200: Animal Diversity

An Introduction to Animal Diversity

• Lets explore our perception of Animal Diversity

BIOS1200: Animal Diversity

PoriferaPlacozoaCnidariaCtenophoraDicyemidaPlatyhelminthesOrthonectaGnathostomaGastrotrichaNematodaNematomorphaKinorhynchaLoriceriferaPriapulaRotiferaAcanthocephalaOnychophoraArthropodaTardigradaMollusca SipunculaEchiuraAnnelidaPogonophoraNemerteaEntoproctaCycliophoraPhoronidaBrachipodaBryozoaChaetognathaEchinodermataHemichordataChordata

What will we be doing? Consider the origin and evolution of animal life Study the evolution and diversity of animal lifeCompare animals’ life histories/body plans etc…

BIOS1200: Animal DiversityAn Introduction to Animal Diversity

• Animal = Latin “animalis”: means ‘having breath’• Need to further qualify this definition though…• Animals are heterotrophs

BIOS1200: Animal Diversity

What defines an animal?

What defines an animal? • Animals are heterotrophs This means that they gain their carbon from ORGANIC sources (i.e. by eating other organisms)

How about heterotrophic bacteria?

Clue – how many cells?

Do they have a true nucleus?

BIOS1200: Animal DiversityAn Introduction to Animal Diversity

• Animal = Latin “animalis”: means ‘having breath’• Need to further qualify this definition though…• Animals are heterotrophs• Animals are multicellular• Animals are eukaryotes

BIOS1200: Animal Diversity

What defines an animal?

Prokaryotes (i.e. bacteria) Eukaryotes (i.e. protozoa, animals, plants)

Small (0.2 - 2.0 μm) Larger (10 - 100 μm)

No nuclear membrane enclosing DNA Have a true nucleus (i.e. genetic material enclosed within membrane)

No membrane-enclosed organelles Membrane-enclosed organelles (including mitochondria and chloroplasts)

Frequently have cell wall and membrane. Usually do not have a cell wall (plants exception) and cell membrane (with CHO)

NB: some older text books/the internet may suggest only eukaryotes have cytoskeletons. see Wickstead & Gull, 2011 for discussion of cytoskeletons in both.

A-level reminder: Prokaryotes vs. Eukaryotes

BIOS1200: Animal Diversity

• Campbell et al. (2008) suggests that animals are “multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers”

• Anyone have a problem with that? • About 10,000 species of sponge… No true tissues but form a collective of cells, with heterotrophic nutrition

Extra reading: Lee et al. (2012)

BIOS1200: Animal Diversity

•What defines an animal?

Defining diversity • “the state or quality of being different or varied”

(Collins Dictionary)Measuring biodiversity• Problems? • What could bias measurements?

BIOS1200: Animal Diversity

Define and Measure Animal Diversity

• The scale of things: small organisms are more likely to be underestimatedbacteria 900010bill

Nematodes are incredibly numerous4/5 28,000 spp – difficult to tell apart

BIOS1200: Animal Diversity

Extra reading: Mora et al. 2011

•Quantifying biodiversity

“if all solid materials except nematode worms were to be eliminated, you could still see the ghostly outline of most of it in nematode worms” (Platt, 1997)

• The scale of things• Accessibility issues

• soil, • deep sea, • rainforest, • areas of conflict, • changing political priorities…

BIOS1200: Animal Diversity

Quantifying biodiversity

Hydrothermal vent communities

Every new expedition to deep sea new spp. Conservative estimates: 91% species still to describe fr. marine envt

Some Recent discoveries

Laotian giant flying squirrel – Aug 2013

BIOS1200: Animal Diversity

Olinguito (Ecuador) – Aug 2013

Junin Tapaculo (Peru cloud forest) – Aug 2013

Electric knife fish (2sg) (Brazil) – Aug 2013

Legless lizards (4 sp) (California) – Sep 2013

Water beetle (Manila) – Sep 2013

• The scale of things • Accessibility • Anthropocentric effects - cultural priorities

BIOS1200: Animal Diversity

Extra reading: Mora et al. 2011

•Quantifying biodiversity

Laotian rock rat11mya Laonastes aenigmamus

Aside for you to ponder………………• The Laotian rock rat or kha-nyou[2] (Laonastes aenigmamus),

sometimes called the "rat-squirrel", is a rodent species of the Khammouan region of Laos. The species was first described in a 2005 article by Paulina Jenkins and coauthors, who considered the animal to be so distinct from all living rodents, they placed it in a new family, Laonastidae. It is in the monotypic genus Laonastes.

• In 2006, the classification of the Laotian rock rat was disputed by Mary Dawson and co-authors. Dawson and her colleagues suggested instead it belongs to the ancient fossil family Diatomyidae, that was thought to have been extinct for 11 million years,[3] since the late Miocene. It would thereby represent a Lazarus taxon. The animals resemble large, dark rats with hairy, thick tails like those of a squirrel. Their skulls are very distinctive and have features that separate them from all other living mammals.

Quantifying biodiversity• The scale of things • Accessibility • Anthropocentric effects - cultural priorities - trends in scientific interest/funding - limitations of senses (cryptic species)

BIOS1200: Animal Diversity

Extra reading: Beheregaray & Caccone 2007, Bickford et al. 2007

Quantifying biodiversity

Olinguito

Extra reading: Brown et al. 2007; Funk et al. 2011; Roca et al. (2001

• Number of species on Earth – basic but elusive information.

• Many undiscovered• Many undescribed• Many have taxonomic issues.• Probably 86% from land and 91% from the sea

await description.

Percentage of described species

Fungi6%

Bacteria1%

Algae 2%

Protozoa2%

Plants16%

Insects 56%

Other inverts16%

Vertebrates3%

What did you choose?

• Multicellular animals having cells differentiated into tissues and organs and usually a digestive cavity.

What are metazoan phyla ?

Unity in diversity: variation on a theme• Animals have unifying characteristics which

are referred to using specific terminology which it is important to understand…

• 30-40 modern metazoan phyla – surviving phyla from hundreds which arose in the Cambrian explosion600mya

BIOS1200: Animal Diversity

Animal Diversity/Unity

Unity in diversity

• Body plans of Cambrian fossils still recognisably have: symmetry, senses, a ‘head’ & segmentation

• WHY?

• Evolutionary advantages

Ancestral constraints• Features in modern phyla are in the

form of distinctive body plans• For example: arthropods have a

hard exoskeletons, birds have feathered wings, horses have four legs etc…

• The developmental processes that lead to these body plans in ancestral forms limit the degree to which new forms arise

• Bounded by ancestral architecture

Comparing animals: Levels of organisation• Animals similarities & differences can be compared at a

hierarchy of organisational levels(increasing complexity)

• Molecular: biochemistry & genetics• Cellular: processes/structures• Tissue: four types shared by metazoans:

• nervous, epithelium, muscle and connective tissue.

BIOS1200: Animal Diversity

Comparing animals: Levels of organisation

BIOS1200: Animal Diversity

• Organ systems: • include circulatory,

respiratory, nervous, skeletal reproductive, excretory

• Whole animal: morphology

• Variation at each hierarchical level increases diversity.

Extra reading: Payne et al. (2009); McClain & Boyer (2009) Haldane (1926)

BIOS1200: Animal Diversity

Complexity and body size• Maximum size an organism can reach is constrained by

scaling considerations• For simple animals – for every doubling in length, surface

area increases four fold (22). The volume of body filled with cells increases eight-fold (23).

• To facilitate increased volume need disproportionate increase in SA (wrinkles/ribbon) OR transport systemscirc

Extra reading: Payne et al. (2009); McClain & Boyer (2009) Haldane (1926)

BIOS1200: Animal Diversity

Increasing Complexity - size

• Increasing complexity permits the evolution of large body size.

• It allows greater buffering against environmental fluctuations.

• It increases niche opportunities and availability.• All of these increase diversity.

Increasing Complexity - evolution

• The organisational hierarchy that facilitates increasing levels of complexity can bee seen in metazoan evolution

• From simple multicellular organisation in the sponges tissue level organisation in jellyfish first simple organ system in flatworms…

• Also evident in this progression in complexity is a change in the general body plan: from asymmetry symmetry

BIOS1200: Animal Diversity

Symmetry

• Most organisms with organisation more complex than sponges exhibit some form of symmetry.

BIOS1200: Animal Diversity

Extra reading: Finnerty (2005)

Symmetry - radial

• Radial symmetry: bisected into two equal halves by any central cut through the axial plane.

• Jellyfish, anemones, coral (echinodermssec) and is first form of symmetry in fossil record (next week)

BIOS1200: Animal Diversity

Extra reading: Finnerty (2005)

Symmetry - radial

• Advantages? Filter-feeding and/or sit-and-wait strategies direction food approaches unimportant.

Disadvantages: No directed movementNo predator avoidanceLimited senses

BIOS1200: Animal Diversity

Extra reading: Finnerty (2005)

Symmetry - bilateral

• Bilateral symmetry: animals can be halved down a central, lateral axis

• Advantages: burrowing dynamics, forward directed movement & sensory specialisation (and cephalisation)

• Favours CNS & paired sense organs judgement of distance (predator)

• Driving forces for bilateralism still being explored by biologists

• Some argue is simply consequence of growth in multicellular animals as cells divide along central axis…

BIOS1200: Animal Diversity

Extra reading: Finnerty (2005); Pecoits (2012)

Developmental characteristics

• There is a set embryonic developmental sequence for all animals.

• This begins after the fertilization of the egg.• The zygote is a single large cell. Cleavage then divides it

into large number of small cells called blastomeres. • Pattern of cleavage is a major defining characteristic of

group to which an animal belongs.

BIOS1200: Animal Diversity

Extra watching: Revision

Cleavage

• In radial cleavage, cells have planes of division parallel to or perpendicular to the poles of the embryo. Cells divide into equally sized units (regulative)

• In spiral cleavage, cells split along an axis at an angle to poles of zygote and cells do not divide equally (mosaic)

BIOS1200: Animal Diversity

Extra watching: Revision

Developmental Cleavage

• Debate about which type of development came first in evolutionary time but in both evolved only once and gave rise to the two major groups of animals:

Echinoderms & vertebrates Everything else

Why does it matter how cells split in early embryogenesis?

BIOS1200: Animal Diversity

Deuterostomes Protostomes

Extra watching: Revision

Protostome/Deuterostome• Protostomes: first mouth. • Deuterostome: second

mouth.• There are different

developmental origins for the mesoderm & the coelom.

• Excision of blastomere in protosome arrests development.

BIOS1200: Animal Diversity

Body cavities: advantages of the coelom• It is “a tube-within-a-tube” which allows greater

flexibility, space for organ systems within the body cavity.• Allow internal processes and movement to independent.• Provides an incompressible fluid- filled hydrostatic skeleton to to antagonise muscle action more efficient movtburrow

• Allows compartmentalisation and segmentation• Development of coelom has allowed evolution of a

greater range and diversity of body plans.

BIOS1200: Animal Diversity

Segmentation• Segmentation allows for

further specialisation of areas for specific functions in isolation from one another

• Some segments could be specialised for propulsion, respiration, reproduction

• Variations at a segmental level increased diversity/

• Evolutionary changes have obscured much segmentation but legacy evidence in annelids and arthropods…

BIOS1200: Animal Diversity

Comparing animals

• Think about similarities between animals and shared characteristics as well as their differences…

• Acoelomate? Coelomate • Segmented? Not segmented? • Symmetry? Asymmetry? • Comparative approach to animal diversity is helpful to

discern evolutionary trends• In company of Linnaeus, Darwin, Wallace and…

Comparing animals

• Aristotle (300 BC) wrote one of the first comparative zoology texts: A History of Animals

• “some animals have all these parts the same, in others they are different from each other. Some of the parts are the same in form…flesh is the same with flesh, and bone with bone. In like manner we may compare the parts of…animals. And in animals belonging to the same class, the parts are the same, only they differ in excess or defect”

BIOS1200: Animal Diversity

BIOS1200: Animal DiversityHomework: Diversity on your doorstep

• A challenge… with prizes. • In groups of four I would like

you to go around the campus and look for examples of:

1) a (non-insect) invertebrate 2) an insect 3) a mammal 4) a bird

1) Take a photo of four species of animal, one from each category. 2) Paste them into a single word document with your names at the top. 3) Find out: common name, scientific name* and the following taxonomic descriptors: Class, Order, Family, and label the photographs with these. 4) Upload to Blackboard discussion forum by next Wednesday at 3pm with your group number in the subject box.

Diversity on your doorstepBIOS1200: Animal Diversity

• Common name: Channel-billed toucan • Scientific name:

RamphastosG vitellinusS

• Class: Aves • Order: Piciformes • Family: Ramphastidae

4) a bird…BIOS1200: Animal Diversity

There will be prizes for: a: best*1 photo b: most obscure species c: oddest*2 species name d: largest species

*1 - as judged by module leader *2 - that makes him laugh most

P.S. Use of Google images or a non-campus setting will result in disqualification…

Diversity on your doorstepBIOS1200: Animal Diversity

• One of these possible amazing prizes

AND…

What do we win?BIOS1200: Animal Diversity

…a sense of pride in your own achievements …and the esteem of your colleagues

What do we win?BIOS1200: Animal Diversity

•Next week we will be thinking about the origins of life:

•Think about: What is life? What are its unifying features? Where do we come from? Where are we going?

•Extra watching on Blackboard: two hour-long documentaries (David Attenborough’s First Life) are in the folder for Week 02. Watch at your leisure.

Homework: to think about for next week

BIOS1200: Animal Diversity

Test yourself – do you know• How to distinguish between asymmetrical animals

and those with bilateral and radial symmetry?• The differences between radial and spiral cleavage?• The distinguishing developmental hallmarks of the

two major groups of bilateral metazoans, the protostomes and deuterostomes?

• What are the four major types of tissues in the body of a metazoan (Kingdom Animalia)?

BIOS1200: Animal Diversity