3. How many species are there Flashcards
what insect do taxonomists use most to study taxonomy
bees
what is a species? what are the 3 concepts that we use to categorize them?
morphological
biological
evolutionary (phylogenetic)
Old estimates show which species in the world has highest abundance.
Insects about 750K
New estimates show which kingdom in the world has highest abundance.
animalia
do we know moree about the numbers of species on earth or in ocean
on earth
what are the most desribed species and most abundant on earth?
insectsh
how many species are there on earth approximately
1.2-1.4 million
which types of organisms are know best
conspicuous
more noticeable species
more work needs to be done on less conspicuous species
most described species are in which species
animals
which species is least described, and predicted to have so many more?
fungi
most predicted organism by kingdom is?
bacteria
what did they find in the abyssal plains of the southeastern atlantic
in africa
very deep in ocean
70% of organisms in the ocean bottom had no identification done
frontiers of biodiveeristy research focuses on which 2 things
identifying neew habitats
identifying largely unknown organisms that live there
what is another popular area to find new species in
hydrothermal vent fauna
what is a common error that occurs during taxonomic work (1)
undercounting
many species look the same and are given same name
what is a common error that occurs during taxonomic work (2)
Overcounting (synonymy )
- they think 2 species look the same because they don’t know how to see difference
- many species given different names because they look different, but they’re ACC the same
do more or less fossil mamal species names stay in use over time
less
which 2 species are seeen as particularly synonymous
butterflies and moths
what are 2 molecular techniques that can help identify species more accurately
- DNA (meta) barcoding (mtDNA)
- using COI for animals mainly - Environmental DNA (eDNA)
- uses water and soil samples where DNA is likely to be well-preserved
how can DNA help taxonomists
-address synonymies
- identify cryptic speciees
- reveals distinct species without rearing
- compare DNA to DNA library and then use for conservation tactics
how can eDNAA help taxonomists
- organism doesn’t need to be present
- identifies organisms from strands shed into nature
- using PCR and 16S RNA
- compare against mammal sequences
- amount of DNA is not always proportional to abundance
why doesnt eDNA proportional to number of organisms
- temporal dependance of eDNA release
- amount of DNA in water may change for biological reasons - Species and spatial dependence of eDNA decay and release
- DNA in water decays faster depending on organism
- DNA can be re-released from sediments across different sites
what else can eDNA help us do
confirm disappeared species
able to confirm presence of organisms that were previously undetected
what does ancient eDNA help recreate
paleo environments
- ice cores decline = mammoth steppe in Yukon was seen
- establish communities that were there before
what is SedaDNA
cellular material that has bound to sedimentary minerals which can protect DNA fragments, especially when frozen in permafrost
what are other application of eDNA (4)
- dung beetles used to sample mammals
- identify viruses and hosts from water holes
- naked mole rats can be detected through air collected in colony
- torpedo that could collect SARS COV2 from wasteewater
Species area curves
S= cA^z
what is z value usuallly and range
0.25
0.1-0.4
how does species richness usually realte to area
increased species richness with increased area
how can you linearize species area graph
ln (S) = ln (C) + z ln(A)
what is z in species area curve
slope of the line
how can we count for the undetected species diversity
by using species-area curve to find big B
what doeos extrapolation doo
- extrapolate from smaller to bigger areas
- exploit the known increasing relationship between area and species
- helps predict number of species we might expect if area we sample increases
is species and area relationship tight
no
using the extrapolation method, how many species of plants do we estimate
4.6 million
what are some limits of extrapolation
- not all biomes have same relationship for plants
- animals of different sizes have different relationships with species-area
how does dispersal affect species area relationship
- species with higher rates of dispersal may have flatter curves , so throws curve ball for extrapolation
what are other ways to extrapolate global biodiversity
- macroecological patterns
- use body size and abundance to extrapolate - species accumulation curves
- use rate of taxonomists name things to extrapolate - ask experts to estimate
how have guesses at big B been
has not gone better over time, still widely disagreed upon
how many species are there eyeballing
7-10 million species
how many species of bacteria do we have eyeballing
more than 1 billion
