ESF Diversity of Life 1 Exam 1

What is biodiversity?

variation at all levels of biological organization

What is genetic diversity?

variation in the genetic make-up between individuals within a population and between populations

What is organismal diversity?

the variation in a particular level of the taxonomic hierarchy (species, genera, and beyond)

What is species richness?

the number of species with a given sampling area

What is species evenness?

how abundant each species is relative to the total number of individuals

What is ecological (ecosystem) diversity?

ecological differences between habitats and biomes

What is alpha diversity?

diversity within an area/ecosystem

What is beta diversity?

difference in alpha diversity between ecosystems

What is gamma diversity?

overall diversity for the different ecosystems in a broad region.

What is the species area relationship?

larger area = more species

What percentage of life is vertebrate?

3%

What percentage of life is invertebrates?

66%

What percentage of life is virus and prokaryotes?

<0.01%

What percentage of life is protists?

11%

What percentage of life is fungi?

4%

What percentage of life is plants?

16%

How many extant species are there?

1.5 million described species

How many extant species is estimated to be on earth? What do most people agree on?

0.5 million to 1 trillion estimated. Most agree 10-12 million.

Why is there such a huge gap when estimating extant species.

taxonomic groups, functional groups, habitats or biomes

What taxonomic groups do we know the least amount?

bacteria, fungi, inverts

What functional group do we know the least amount from?

Parasites

What habitats or biomes do we know the least about?

Soils and deep ocean.

What percentage of extant species are still undescribed?

90%

What are the two ways we measure biodiversity? Explain each.

Extrapolation - canvas experts, use patterns of discovering new species, use well studied areas to infer about larger areas

Diversity Indices - Shannon-Weiner

What are the main issues with measuring biodiversity?

Complicated, extrapolation from small to large compounds error, some species are harder to find than others (uneven detection), truly representative samples are hard to get.

How old is earth?

4.5 billion years

Precambrian Archeon Eon

low oxygen, first life arises (chemoautotrophic prokaryotes that looked like blue-green algae), cyanobacteria begins photosynthesizing (formed stromatolites),

Precambrian Proterozoic Eon

Great Oxygenation Event (1% to 10%), predatory eukaryotes evolve (small and soft bodied until Cambrian).

What was the Great Oxygenation Event?

oxygenation through photosynthesis and petrochemical dissociation (breaks up water through UV) during the Precambrian Proterozoic Eon.

Cryogenian Period

massive ice age, glaciers reach equators, possible increase in diversity in Ediacaran Period.

Ediacaran Period

proliferation of eukaryotic, multicellular organisms

Phanerozoic Eon

life in oceans begins and moves to land and all invert phyla appear

Cambrian period

Cambrian explosion, algae diversify + Meiosis, major animal phyla appear, metazoan body plan, marine life dominant

What was the Cambrian Explosion?

a dramatic diversification of life that began about 540 million years ago

Ordovician Period

Shallow seas + an increase in invert diversity, fish vertebrates with true bones appear. First life on land. Mass extinction.

Triassic Period

early mammals + dinos, warm and dry climate, slow recovery from Permian.

Jurassic

first birds, cycads dominate, largest land animals of all time

What are cycads?

Slow-growing gymnosperms of tropical and subtropical regions

Cretaceous

high sea levels, first angiosperms, age of reptiles, mass extinction.

Phanerozoic Eon

mammals dominate land, pleistocene epoch (last major ice age(s)), holocene epoc (after ice age allows for species radiation), anthropocene.

What was the Permian Extinction?

Mass Extinction from volcanic activity, over exposure to CO2, Hot temp, and reduced oxygen. Occurred in pulses. The largest extinction. 95% of life gone.

End of Triassic extinction

80% of life gone due to volcanism

Cretaceous - Tertiary Extinction (K-T Event)

75%, dinosaur extinction. Possibly from asteroid, sea level decrease, or intensive volcanic activity.

What is the holocene/anthropocene?

human caused massed extinction. Rates are 100x higher than the background extinction rate. Timing corresponds with industrialization.

Is biodiversity always increasing?

Yes, but erratically, according to the fossil record.

What is taxonomy?

the science of naming and classifying organisms

Taxon

group or level of organization into which organisms are classified

Where did genera come from?

The Roman Empire!! HOO RAHHH!!

How did Aristotle classify plants and animals?

Based on air, earth, water habitats.

What did the Middle Ages add to taxonomy?

latin to systematically record sp. and the polynomial system

What is the polynomial system?

the older form of naming organisms before the advent of binomial system. In polynomial system, a generic name and specific name which consisted of many words were used.

What is the binomial system?

Gives every organism its own two-part Latin name

1st part - the genus that the organism belongs to - gives information on the organism's ancestry

2nd part - the species

Who was Carolus Linnaeus?

He created binomial nomenclature. Created kingdom, phylum class, order, family, genus sp. We added domain.

How do you describe a species.

1. Get specimens

2. Send to experts to say you are describing it

3. Describe it

4. Binomial name

5. Peer reviewed journal (need five institutions)

6. Specimen collected is the holotype.

What is a holotype specimen?

A single specimen expressly designated as the name-bearing "type" by the original author of the species. The first specimen.

What is a isotype?

collected at same place and time as holotype

What are characters?

Any recognizable trait/feature (eyes)

What are character states?

Discrete condition within a character (blue eyes)

What is a paratype?

collected at a different place or time than holotype.

When does taxonomy need updating?

When species are split/lumped.

What is systematics?

study of diversity of organisms and their evolutionary relationships

What is a phylogenetic tree?

inferred evolutionary relationships?

What does it mean for a phylogenetic tree to be parsimonious?

It has the least number of steps and thus is the most likely to have happened.

What is a cladogram?

A cladogram links groups of organisms by showing how evolutionary lines, or lineages, branched off from common ancestors.

What are synapomorphies?

newly derived character state shared by all members of a taxon.

What is a clade?

Common ancestor + all its descendents (AKA monophyletic group)

What is a praphyletic group?

includes most recent common ancestor but not all of its descendents.

What is a polyphyletic group?

Grouping derived from more than one ancestor.

What is an outgroup?

taxon that serves as a reference group for other taxa in a cladogram.

What are direct uses of biodiversity? List as many as you can.

Food, medicine, biocontrol, industrial materials, recreational harvesting, ecotourism.

Where does 75% of the worlds food supply come from.

Eight species (yikes!)

How many new drugs are made every decade?

500 from plants, fungi, and bacteria.

What types of industrial materials come from biodiversity?

fibers, dyes, gums, adhesives

What are indirect uses of biodiversity? List them all.

Carbon sequestration, water purification, flood control, nutrient cycling, pollination, food webs

What is option value?

the worth of something we might use later. You are saving a portion of the forest.

What is bequest value?

leave intact for future generations. You are saving all of a forest.

What is existence value?

human value placed on living things. Its good because it exists and is useful.

Intrinsic value of biodiversity

Value of biodiversity based on its existence, regardless of whether it has any usefulness to humans.

What is the Precautionary Principle?

Biodiversity elements with potential use should not be lost simply because we currently do not know their worth

What is insitu conservation?

on-site conservation or the conservation of genetic resources in natural populations of plant or animal species

What are examples of insitu conservation?

promoting sustainability, controlling invasive species, restoring degraded habitat, establishing protected areas.

What is exsitu conservation?

off-site conservation - the process of protecting an endangered species, variety or breed, of plant or animal outside its natural habitat

What are examples of exsitu conservation?

seed banks and zoos, culture collections, captive breeding and artificial propagation

What are the three major trends of biodiversity distribution?

Biodiversity increases with area, biodiversity increases from the poles to the equator, biodiversity decreases from sea level to high peaks.

What is an endemic species?

species found in one place and nowhere else

What are the three trends in endemism?

Peaks on oceanic islands, increases from poles to the equator, something else (help)

Who is Norman Myers?

He proposed the idea to focus conservation efforts on areas with high biodiversity.

How many biodiversity hotspots are there in the world?

There WAS 18, but now there is 25.

What were the criteria to name somewhere a biodiversity hotspot?

1. Atleast 1500 endemic species of vascular plants. Must be irreplaceable.

2. Lost atleast 70% of original habitat. Must be threatened.

How much of the land on earth is covered by biodiversity hotspots?

1.4%

What percentage of plants and animals is represented in biodiversity hotspots?

45% of plants and ____% of animals (help)

What are the negatives to the biodiversity hotspot idea? On Exam

Limited to well known taxa.

Limited to terrestrial realm

Focused mainly on species richness

Targets geopolitical areas with geopolitical conservation prospects

Difficult to accurately predict cost of conservation across hotspots.

What other troves of missing virus taxa are very likely out there?

Namely in taxa such as reptiles, amphibians, fish etc

When did eukaryotes evolve?

Precambrian Proterozoic Eon

What dominated life until the Cambrian Explosion?

small, soft bodied, eukaryotes.

Why was the snowball earth (slushball) important?

Lead to more diversity in the ediacaran.

When did nearly all invertebrate phyla appear?

Phanerozoic Eon.

The higher you go in altitude, what happens to biodiversity?

Decreases.

When did algae diversify?

Cambrian

When did most major animal phyla appear?

Cambrian