MBIO162 Whole Exam Set 2

What is the Linnaean classical hierarchical classification of life?

Kingdom, Phylum, Class, Order, Family, Genus, Species

What is phylogeny?

The evolutionary history of an organism or groups of organisms

What is cladistics?

A method of classification using hypothesised evolutionary relationships among organisms.

What do cladograms assume?

Clades share distinct features and that clades are more closely related to each other than anyone else.

What is the species-area relationship?

As the size of a geographical area increases so too does the number of species it contains.

What are the issues of scale with the species-area relationship?

-Local-regional diversity eg. large area of desert will have less tress than small area of forest

-Patterns may be obscured by gradients

-Costa Rica 1/6 land area of UK but has 1.5-2k butterfly species compared to the UK's 60

How many food chain connections are there?

3 terrestrial and 5 marine

Facts about the biodiversity of the sea

-All 34 animal phyla except Onychophora, 2/3 exclusively marine

-15% of named species are marine >250k marine species

-98% are benthic and live in/on seafloor

-2% are pelagic and live floating or swimming

-Few, large photosynthetic organisms and short lived microscopic algae

-Dominant herbivores are micro (copepods)

-Majority of large animals are carnivorous

-Grazing ingests entire autotroph

Facts about the biodiversity of the land

-Dominated by persistent long-lived large flowering plants

-Large dominant herbivores

-Grazing rarely removes significant amounts of communities- indigestible parts

What biogeographical region contains the most biodiversity?

Neotropics

3-4 tropical regions contain >2/3 of biodiversity, 50-80% of species- high origination rates and low extinction rates

Indo-western Pacific has highest marine biodiversity

What is the latitudinal gradient of biodiversity?

Species richness increases towards the equator in both terrestrial and marine systems.

What is the gradient of biodiversity in shallow waters?

Increase in species richness towards the equator

No pattern in coral reef fish

Amphipods, isopods and bivalve highest before reach equator

What is the gradient of biodiversity in the Deep Sea?

Increase in richness towards the equator for bivalves, gastropods, and isopods

Foraminiferans highest before reach equator

What is the gradient of biodiversity in the Pelagic?

Increase in richness towards the equator- ostracods, euphausiids (krill), shrimp, fish (N hemisphere), bacteria

Littoral/sublittoral

8% area of sea bed

0-200m depth

1-21 atm

5-25*C

Bathyal

75% area of sea bed

200-4000m depth

21-401 atm

5-15*C

Abyssal

76% area of sea bed

4000-11,500m depth

401-1151 atm

<5*C

Hadal

1% area of sea bed

6000-11,500m depth

601-1151 atm

<3.5*C

What group shows a peak in species richness before they reach the equator?

Foraminiferans

What is the relationship between biodiversity and elevation?

Species richness peaks at 1000m then decreases as elevation increases.

At what oceanic depth did Edward Forbes hypothesise that animal life would disapear?

550m or 300 fathoms

What is the relationship between biodiversity and depth?

Species richness peaks at 0.3-4.7 km and then decreases with depth

What is true about species richness in the ocean?

It peaks at intermediate depths

What is a biological species?

An interbreeding natural population that does not mate with other groups- is reproductively isolated from others.

What is a morphological species?

Smallest natural populations permanently separated from each other by a distinct discontinuity in heritable characteristics.

What is an evolutionary species?

Single lineage of ancestor-descendent populations distinct from other such lineages and which has its own evolutionary tendencies and historical fate.

How many species are there?

13.5 million species with 1.75 million currently described

What group has the highest number of species?

Arthropoda- 3 to 50+ million species

100+ phyla

Most animals= insects (85% of animal diversity)

Most species of plants= angiosperms

Most mammals= rodents

Biodiversity is not evenly distributed between groups

Most biodiversity is contributed by few phyla and most phyla are not very diverse

What are the hierarchy's of biodiversity?

Genetic, Organismal, Ecological

How many new species are discovered each year?

13,000

What is the significance of Aristotle to biodiversity?

384-322 BC

1st marine scientist

Wrote History Animalium

Great chain of being

Significant people in classification

Carl Linnaeus- Hierarchal classification KPCOFGS based on how organisms look

Whittaker 1960s- 5 Kingdom approach Plants, Animals, Fungi, Protista, Monera emphasising macroscopic life

Woese 1970s- 3 Domain system Archea, Bacteria, Eukarya based on molecules

What is the significance of Theophrastus to biodiversity?

370-289 BC

Wrote Historia Planetarium

What were the earliest precambrian animals like?

Precambrian= 4.6 billion to 500 million years ago

Ediacaran fauna

-Dickinsonia worm 550Mya

-Carbonaceous chert clast 3,465 Mya 5 taxa in hydrothermal vent deposits

-Strange shapes- sheet/leaf like

-Soft bodies

-No mouth or gut

-Low O2 7-10% of present

Ancestors of present day animals but Seilacher says no descendants

When was the Cambrian explosion and what appeared?

550 million years ago

All major animal groups and the first animals with hard parts

Arthropods (Trilobites), Brachiopods (Lamp shell), Chordates (Pikaia), Molluscs (Snails), Graptolite (Hemichordata)

What allowed biodiversity to increase?

-Continents breaking up- increased area of continental shelf provided new habitat in shallow seas

-Climate- warmer and critical O2

-Developmental genetics and origin of major phyla- mutation of Hox gene allowed morphological change

What is biodiversity?

The variety of life in all its manifestations.

What is surrogacy?

Correlates the measure of biodiversity you want.

Shown on a graph as number of species vs number of genera.

What are the issues of eDNA as a measure of biodiversity?

-Require refinement/improved calibration/validation at every level

-Better understanding eDNA natural history needed

-Origins, state, lifetime, and transportation cause ecological and physical limitations of eDNA use

What is the value of biodiversity for the food industry?

95% of all protein

1/2 habitable land used for agriculture

99% of energy consumed

1 billion people depend on wild food

12,500 edible angiosperms

200 domesticated plants 2.7 billion tons/year