Classification, Biodiversity and Conservation Flashcards
biological species concept
a group of organisms with similar morphological and physiological features that are able to breed together and produce fertile offspring
morphological
physical/structural features of an organism that can be studied and used to investigate the relatedness of organisms of different species
physiological
physiology is the study of the functions and mechanistic processes that occur in a living system. physiology focuses on how organisms, organ systems, individual organs, cells and biomolecules carry out the chemical and physical functions in a living system
morphological species concept
grouping together organisms that share many physical features that distinguish them from other species
ecological species concept
a population of similar organisms living in the same area at the same time
binomial system
a two-part scientific name given to all species
Taxonomy
-the practice of biological classification
-involves organising and grouping similar organisms into a series of categories or taxa
-it can make them easier to understand and remember
Highest taxonomical rank within the hierarchical classification system of organisms
Domain
What has a major role in the classification of organisms into the three domains
cell type:
-Prokaryotic cells are easily distinguishable in that they lack a nucleus
-Eukaryotic cells have compartmentalised structures, with at least their genetic material segregated from the rest of the cell in a nucleus
what have scientists realised based upon molecular analysis of RNA genes in particular
that using cell type to classify organisms is insufficient, and that prokaryotes could be divided into two separate groups (domains)
The three domains are:
Archaea (prokaryotes)
Bacteria (prokaryotes)
Eukarya (eukaryotes)
How archaea is similar to bacteria
-sometimes referred to as the extremophile prokaryotes
-were first discovered living in extreme environments, but not all archaea do
-cells have no nucleus (and so are prokaryotic)
-a similar size range as bacteria
-metabolism is similar between the two groups
Features that distinguish archaea from bacteria
-Unique lipids being found in the membranes of their cells
-No peptidoglycan in their cell walls
-Ribosomal structure (particularly that of the small subunit) are more similar to the eukaryotic ribosome than that of the bacteria
-DNA transcription is more similar to that of eukaryotes
How membrane lipids of the archaea domain are unique
-Not found in any bacterial or eukaryotic cells
-The membrane lipids of Archaea consist of branched hydrocarbon chains bonded to glycerol by ether linkages, a far cry from bacteria’s membrane lipids which consists of unbranched hydrocarbon chains bonded to glycerol by ester linkages
How ribosomal RNA of the archaea domain are unique
-Both Archaea and Bacteria possess 70S ribosomes, but the 70S ribosomes in Archaea possess a smaller subunit that is more similar to the subunit found in Eukaryotic ribosomes than subunits in Bacterial ribosomes:
*The base sequences of ribosomal RNA in Archaea show more similarity to the rRNA of Eukarya than Bacteria
*The primary structure of ribosome proteins in Archaea show more similarity to the ribosome proteins in Eukarya than Bacteria
How cell wall composition in the archaea domain are unique
Organisms from the Bacteria domain have cells that always possess cell walls with peptidoglycan while organisms from the Archaea domain also have cells that always possess cell walls, however these do not contain peptidoglycan
Give an example of a species in the archaea domain
Halobacterium salinarum are a species of the archaea domain that can be found in environments with high salt concentrations like the Dead Sea
Bacteria
-organisms that have prokaryotic cells which contain no nucleus
-vary in size over a wide range: the smallest are bigger than the largest known-viruses and the largest are smaller that the smallest known single-celled eukaryotes
-cells divide by binary fission
An example of a species in the bacterial domain
Staphylococcus pneumoniae is a bacteria species that causes pneumonia
Eukarya
-organisms that have eukaryotic cells with nuclei and membrane-bound organelles
-vary massively in size from single-celled organisms several micrometres across to large multicellular organisms many-metres in size, such as blue whales
-cells divide by mitosis
-can reproduce sexually or asexually
Example of a species in the eukarya domain
Canis lupus also known as wolves
Lowest taxonomical rank within the hierarchical classification system of organisms
species
Similar species can be grouped in a
genus
Similar genuses can be grouped in a
family
Similar families can be grouped into an
order
Similar orders can be grouped into a
class
Similar classes can be grouped into a
phylum
Similar phyla can be grouped into a
kingdom
Similar kingdoms can be grouped into a
domain
a mnemonic to remember the different ranks in the taxonomic classification system
Kings Play Chess On Fancy Gold Squares
Kingdom Phylum Class Order Family Genus Species
The higher ranks in the hierarchical classification system contain
more organisms with less similarity between them
The lower ranks in the hierarchical classification system contain
fewer organisms with more similarity between them
The 4 kingdoms in domain Eurkya
Protoctista
Fungi
Plantae
Animalia
Kingdom Protoctista
-a broad group of cellular life that encompasses all eukaryotic cells that do not belong to the other three eukaryotic kingdoms
-show great diversity in all aspects of life including structure, life cycle, feeding and trophic levels and well as modes of locomotion
-can exist as single-celled organisms or as a group of similar cells
-A group of Protoctista known as protozoa possess cells similar to animal cells; their cells have no cell wall
-Another group of Protoctista known as algae possess cells similar to plant cells; their cells have cellulose cell walls and chloroplasts
An example of a species in the kingdom Protoctista
Stentor roseli is a protoctist that has flagella all over its body which help it feed and move
Kingdom Fungi
-A fungus is thought to be the world oldest organism thought to be aged somewhere between 1500 - 10,000 years old
-cells of fungi possess non-cellulose cell walls (often made of the polysaccharides chitin and glucans) and don’t have cilia
-Heterotrophs:
* They use organic compounds made by other organisms as their source of energy and molecules for metabolism
* They obtain this energy and carbon by digesting dead/decaying matter extracellularly or from being parasites on living organisms
-reproduce using spores that disperse onto the ground nearby
-have a simple body form:
* They can be unicellular (like the common baker’s yeast Saccharomyces cerevisiae)
* Some consist of long threads called hyphae that grow from the main fungus body (mycelium)
* Larger fungi possess fruiting bodies that release large numbers of spores
An example of a species in the kingdom Fungi
The mould found on bread is actually a fungus: bread mould fungus Rhizopus nigricans
Kingdom Plantae
-Multicellular eukaryotic organisms
-Plant cells have:
* All have cell walls composed of cellulose
* Possess large (and usually permanent) vacuoles that provide structural support
* Are able to differentiate into specialized cells to form tissues and organs
* Possess chloroplasts that enable photosynthesis (not all plant cells have chloroplasts)
* Can sometimes have flagella
-They are autotrophs; they can synthesize their organic compounds and molecules for energy use and building biomass from inorganic compounds
-They have complex body forms; such as branching systems above and below the ground
An example of a species in the kingdom Plantae
Bristlecone pines are found in the USA, it is estimated that some of them could be 3000 years old
Kingdom Animalia
-Multicellular eukaryotic organisms
-Animal cells:
* Are able to differentiate into many different specialised cell types that can form tissues and organs
* Have small temporary vacuoles (for example, lysosomes)
* Have no cell walls
* Sometimes have cilia
-They are heterotrophs; have a wide range of feeding mechanisms
-They have a wide range of body forms:
* Communication within their complex body forms takes place through a nervous system and chemical signalling
An example of a species in the Kingdom Animalia
Blue whales are the largest living animal species
Viruses
-microorganisms that can only be seen using an electron microscope
-have no cellular structure (and so are acellular and no metabolism)
-hijack the DNA replication machinery in host cells; energy viruses need for replication is provided by respiration in the host cell
-possess none of the characteristic features used for classifying organisms so they sit outside of the three-domain classification system
-there is a wide-ranging debate as to whether viruses should be classified as ‘living’ or ‘non-living’ based on their inability to carry out the defining features of life outside of a host cell
According to what are viruses classified
according to the type of nucleic acid (RNA or DNA) their genome is made from, and whether it is single-stranded or double-stranded
How is genetic material in viruses different from the one present in cellular organisms
In cellular organisms like animals and plants, DNA is always double-stranded and RNA is usually always single-stranded, however in viruses, DNA and RNA can be either single-stranded or double-stranded
The four groups of DNA that exist
1) DNA single-stranded viruses
2) DNA double-stranded viruses
3) RNA single-stranded viruses
4) RNA double-stranded viruses
genome of SARS-CoV-2, the virus responsible for the COVID-19 pandemic is RNA single-stranded
Community
when it comes to ecosystems
a group of species that interact with each other
Ecosystem
a relatively self-contained community of interacting organisms and the environment they live in, and interact with
The two components that make up an ecosystem
living (biotic) components and non-living (abiotic)components
habitat
The place where a species lives within an ecosystem
niche
-The role that species plays within an ecosystem; how an organism fits into the ecosystem
-Encompasses where in the environment the organism is, how it gets its energy and how it interacts with other species and its physical environment
Biodiversity
a study of all the variation that exists within and between all forms of life; looks at the range and variety of genes, species and habitats within a particular region
Three ways you can assess biodiversity
-The number and range of different ecosystems and habitats
-The number of species and their relative abundance
-The genetic variation within each species
why is biodiversity important
for the resilience of ecosystems, in that it allows them to resist changes in the environment
Ecosystem or habitat diversity
-The range of different ecosystems or habitats within a particular area or region
-If there is a large number of different habitats within an area, then that area has high biodiversity
-If there is only one or two different habitats then an area has low biodiversity
Species diversity
-An ecosystem such as a tropical rainforest that has a very high number of different species would be described as species-rich; species richness is the number of species within an ecosystem
-Species diversity looks at the number of different species in an ecosystem, and also the evenness of abundance across the different species present
-The greater the number of species in an ecosystem, and the more evenly distributed the number of organisms are among each species, then the greater the species diversity [For example, an ecosystem can have a large number of different species but for some species, there may only be 3 or 4 individuals. As a result, this ecosystem does not necessarily have high species diversity]
-Ecosystems with high species diversity are usually more stable than those with lower species diversity as they are more resilient to environmental changes
Genetic diversity
-The genetic diversity within a species is the diversity of alleles and genes in the genome of species
-Genetic diversity is measured by working out the proportion of genes that have more than one form (allele) and how many possible alleles each gene has
-There can be genetic differences or diversity between populations of the same species. This may be because the two populations occupy slightly different ranges in their habitat and so are subject to slightly different selection pressures that affect the allele frequencies in their populations
-Genetic diversity within a single population has also been observed. This diversity in a species is important as it can help the population adapt to, and survive, changes in the environment. The changes could be in biotic factors such as new predators, pathogens and competition with other species
Or the changes could be through abiotic factors like temperature, humidity and rainfall
Finding out which species live in an ecosystem and the size of the populations requires
the identification and cataloguing of all organisms present to build a species list
For which types ecosystems is it possible to identify and catalogue all of the organisms present to build a species list
Ecosystems with very small areas or where the species are very large like trees. For larger and more complex ecosystems like rainforests, it is simply impossible to find, identify and count every organism that exists there
How to assess the biodiversity of larger more complex ecosystems
By taking different samples of the area using it to make an estimate for the total species numbers in the area
Sampling
a method of investigating the abundance and distribution of species and populations
The two different types of sampling
Random
Systematic
random sampling and it’s advantages
-In random sampling the positions of the sampling points are completely random or due to chance
-This method is beneficial because it means there will be no bias by the person that is carrying out the sampling that may affect the results
systematic sampling and it’s disadvantages
-In systematic sampling the positions of the sampling points are chosen by the person carrying out the sampling
-There is a possibility that the person choosing could show bias towards or against certain areas
Individuals may deliberately place the quadrats in areas with the least species as these will be easier and quicker to count; this is unrepresentative of the whole area
when is random sampling the best choice
when a sampling area is reasonably uniform or has no clear pattern to the way the species are distributed
distribution of a species
describes how it is spread throughout the ecosystem
abundance of a species
the number of individuals of that species
Practical methods to assess the distribution and abundance of a species in an area
Frame Quadrats
Line and Belt Transects
Mark-release-capture
Sampling using frame quadrats
-When carrying out sampling, square frames called quadrats can be used to mark off the area being sampled
-Quadrats of different sizes can be used depending on what is being measured and what is most suitable in the space the samples are being made in
-Quadrats must be laid randomly in the area to avoid sampling bias. This random sampling can be done by converting the sampling area into a grid format and labelling each square on the grid with a number. Then a random number generator is used to pick the sample points
-Once the quadrat has been laid on the chosen sample point the abundance of all the different species present can be recorded
Species frequency
the probability that the species will be found within any quadrat in the sample area
Species density
indicates how many individuals of that species there are per unit area
obtaining results from sampling using quadrats
-To find species frequency by dividing the number of quadrats that the species was present in by the total number of quadrats and then multiplied by 100
-To find species density by dividing the number of individuals counted across all quadrats by the total area of all the quadrats
What to do when it’s difficult to count individual plants or organisms
-Estimate the percentage cover of the species within the quadrat
-The quadrat is divided into 100 smaller squares. The number of squares the species is found in is equivalent to its percentage cover in that quadrat
When may it be appropriate to use systematic sampling to investigate species distribution
Throughout areas, that have changes in the physical conditions. For example, there may be changes in altitude, soil pH or light intensity.
What can transects help show when sampling
it helps show how species distribution changes with the different physical conditions in the area
transect
a line represented by a measuring tape, along which sample are taken
Procedure for a line transect
-Lay out a measuring tape in a straight line across the sample area
-At equal distances along the tape record the identity of the organisms that touch the line. For example, every 2m
-This produces qualitative data
Procedure for a belt transect
-Place quadrats at regular intervals along the tape and record the abundance of each species within each quadrat
-This produces quantitative data
Method used for estimating the number of individuals in a population of mobile animals
The mark-release-capture method is used in conjunction with the Lincoln Index
Estimating the number of individuals in a single species in the area
1) The first large sample is taken. As many individuals as possible are caught, counted and marked in a way that won’t affect their survival
2) They are returned to their habitat and allowed to randomly mix with the rest of the population
3) When a sufficient amount of time has passed another large sample is captured
4) The number of marked and unmarked individuals within the sample are counted
5) The proportion of marked to unmarked individuals is used to calculate an estimate of the population size
Lincoln index with mark-release-recapture formula
N = n1 x n2 / m2
Where:
N = population estimate
n1 = number of marked individuals released
n2 = number of individuals in the second sample (marked and unmarked)
m2 = number of marked individuals in the second sample
Correlation
an association or relationship between variables
Causation
occurs when one variable has an influence or is influenced by, another
apparent correlation between variables can be analysed using
scatter graphs and different statistical tests
correlation coefficient (r) indicates
used to determine whether a linear relationship exists between variables and how strong that relationship is
Perfect correlation occurs when
all of the data points lie on a straight line with a correlation coefficient of 1 or -1
Positive correlation
as variable A increases, variable B increases
Negative correlation
as variable A increases, variable B decreases
correlation coefficient when theirs no correlation between variables
correlation coefficient will be 0
Pearson’s linear correlation
a statistical test that determines whether there is linear correlation between two variables
Data while using Pearson’s linear correlation should be
-Be quantitative
-Show normal distribution
Method of Pearson’s linear correlation
Step 1: Create a scatter graph of data gathered and identify if a linear correlation exists
Step 2: State a null hypothesis
Step 3: Use the equation to work out Pearson’s correlation coefficient r
Step 4: If the correlation coefficient r is close to 1 or -1 then it can be stated that there is a strong linear correlation between the two variables and the null hypothesis can be rejected
Pearson’s linear correlation (r) formula
r = Σxy-nx̄ȳ/(n-1)SxSy
Where:
r = correlation coefficient
x = no. of species A
y = no. of species B
n = no. of readings
Sx = standard deviation of species A
Sy = standard deviation of species B
x̄ = mean no. of species A
ȳ = mean no. of species B
Spearman’s rank correlation
determines whether there is correlation between variables that don’t show a normal distribution
Method of Spearman’s rank correlation
Step 1: Create a scatter graph and identify possible linear correlation
Step 2: State a null hypothesis
Step 3: Use the equation to work out Spearman’s rank correlation coefficient r
Step 4: Refer to a table that relates critical values of rs to levels of probability
Step 5: If the value calculated for Spearman’s rank is greater than the critical value for the number of samples in the data ( n ) at the 0.05 probability level (p), then the null hypothesis can be rejected, meaning there is a correlation between two variables
Spearman’s rank correlation formula
rs = 1-(6xΣD^2/n^3-n)
Where:
rs = spearman’s rank coefficient
D = difference in rank
n = number of samples
Once the abundance of different species in an area has been recorded the results can be used to
calculate the species diversity or biodiversity for that area
What can be used to quantify the biodiversity of an area
Simpson’s index of diversity (D)
Simpson’s index formula
D = 1-(Σ(n/N)^2)
Where:
D = biodiversity of an area
n = number of individuals of each type present in the sample
N = the total number of all individuals of all types present in the sample
Method to calculate Simpson’s Index:
Step 1: First step is to calculate n / N for each species
Step 2: Square each of these values
Step 3: Add them together and subtract the total from 1
Step 4: The possible values of D are significant. The value of D can fall between 0 and 1. Values near 1 indicate high levels of biodiversity. Values near 0 indicate low levels of biodiversity
Extinction
when a species comes to an end or dies out
Mass extinction events
when a very large number of species go extinct at one time
Past mass extinctions were likely caused by
major and sudden shifts in the environment such as an Ice Age or an asteroid hitting the earth
What do many students believe about current rates of extinction in recent years
that the earth is undergoing a current mass extinction with humans being the main cause
Possible reasons for current mass extinctions
-Climate change
-Competition
-Introduction of species
-Hunting by Humans
-Degradation and loss of habitats
why populations and species can become extinct as a result of climate change
-The large scale burning of fossil fuels by humans in recent years has led to a large increase in the levels of carbon dioxide in the atmosphere, creating the greenhouse effect
-The increased carbon dioxide concentration in the atmosphere has had several knock-on effects on ecosystems around the world
* There has been an increase in the mean global temperature
* Sea levels are rising
* Ocean temperatures and acidity are rising
* Ice caps are melting
-These knock-on effects have massively changed the habitats of some species, so much so that some are no longer able to survive in the new environmental conditions
why populations and species can become extinct as a result of competition
-When there is a limited supply of resources within an area competition between individuals for the same resource can occur
-The resources could be food, water, habitat and reproductive mates
-Competition can exist within species and between species
-Competition reduces the population size of a species
-Competition with humans has become a major problem for some species in the last 100 years as humans have taken their food, water and habitat
why populations and species can become extinct as a result of introduction of species
-When humans colonised new land they would often exchange animal and plant species between their home country and the new land
-These introduced species are non-native
-Non-native species can be highly problematic as they often have no natural competitors, predators or pathogens that help limit population growth
-Without these natural population checks, non-native species can massively increase in number
-The large numbers of non-native species can negatively affect the native species through factors such as competition and disease
why populations and species can become extinct as a result of hunting by humans
-The evolution of livestock has negated the need for current humans to hunt wild animals (some humans in underdeveloped countries still have to hunt animals for survival)
-However, the hunting of wild animals is still common and has become a sport for some individuals
-The rarer and more vulnerable species are often more desirable for a sport hunter
-If too many individuals within a species are killed then the population can become so small that it is no longer able to survive
why populations and species can become extinct as a result of degradation & loss of habitats
-This is the main cause of species extinction
-Over recent years humans have aggressively destroyed animals habitats by cutting down forests, draining wetlands and polluting the water, soil and air
-This is highly problematic as species are adapted to survive within their specific habitat that has particular environmental conditions
-Without their habitat organisms will not get the resources they need to survive
-As their habitat area gets reduced a species will search for other suitable habitats or compete with others for the remaining habitat
-Eventually the range of habitat can become so small or non-existent that a species is not able to survive and goes extinct
Why small populations are so much more vulnerable to extinction
-A smaller population has increased levels of inbreeding, which reduces the genetic variation in the population
-Genetic drift has a larger impact on a small population leading to an even further decrease in genetic variation
-Genetic variation is important as it allows a species to adapt and survive environmental change; it improves its fitness
-So a small population has a lower fitness meaning increased mortality and decreased reproduction
Reasons for maintaining biodiversity
-Ecological
-Economic
-Aesthetic
-Social
-Moral/ethical
-Environmental
-Agricultural
Ecological reasons for maintaining biodiversity
Biodiversity increases the stability of an ecosystem. A more diverse ecosystem is better able to survive and adapt to environmental changes or threats
Keystone species
Species that have a larger impact on the ecosystem than others in communities. When these species are lost there are several knock-on effects
Economical reasons for maintaining biodiversity
-A range of organisms contribute to medicine, ecotourism, science and tourism
-Many of the medicines used today have originated from plants, fungi and bacteria. Due to the large number of drugs that have already been sourced from nature it is reasonable to assume that there are other drugs, yet to be found in nature, that could be used in the future
-Ecotourism a major source of income for many countries. Increased tourism in a country contributes to the economy and provides jobs
Aesthetical reasons for maintaining biodiversity
Humans find great joy and pleasure in the beauty of nature. It provides inspiration for creatives such as photographers, poets, musicians and artists
Social reasons for maintaining biodiversity
-Many people enjoy spending time in the natural environment. There are many activities that people can do together in nature, e.g. birdwatching, walking, climbing
-Such environments may be lost if they are not conserved, with the loss of the social benefits that they can bring
Moral/ethical reasons for maintaining biodiversity
-Humans have a moral obligation to prevent the loss of biodiversity that results from human activities
-Humans share the planet with millions of others species and they have no right to cause the extinction of other species
-As humans are the most intelligent species on the planet the responsibility falls upon their shoulders to protect and value all of the organisms on the planet
Environmental reasons for maintaining biodiversity
-Humans need diverse ecosystems because of the essential environmental services they provide
-Plants absorb carbon dioxide from the atmosphere and help to reduce the greenhouse effect and climate change
-Microorganisms digest and break down the masses of organic waste that are produced by larger organisms
-Humans have irrigation and drinking water thanks to the transpiration of plants and their contribution to the water cycle
-Different fungi and bacteria species are a major part of the nutrient cycle that allows for nutrients to re-enter the soil for further plant growth
-Plants are producers in food webs. They are both a direct and indirect energy source for humans through fruit, vegetables and meat
Agricultural reasons for maintaining biodiversity
-Most of the crops that humans grow are very uniform with low genetic diversity
-The wild relatives of crops can provide a source of genetic diversity to rescue crops that are affected by disease or other disasters. However, many of the wild relative species are under threat due to habitat destruction and climate change
endangered species
a species that is being threatened with extinction
ideal way to conserve a species
a species should be kept in their natural habitat (conserved areas) as all the support systems they need to maintain life already exist there
When it’s not possible to protect endangered species in their natural habitats than the next best thing is
They can be captured and placed in captivity for conservation efforts
Ways that scientists have come up with in order to preserve long-term survival of endangered species
Frozen zoos
Seed banks
Types of conserved areas
National parks
Marine parks
How national parks conserve species
-National parks are areas within countries where the wildlife and environment are protected
-Governments control these areas and pass legislation to ensure their protection
-There are several restrictions:
* Humans access is strictly controlled
* Industrial activities such as agriculture and building are tightly regulated
* Hunting is limited or completely prohibited
How marine parks conserve species
-Marine parks are protected areas of water that have been set up for the conservation of endangered marine ecosystems and species
-They also have restrictions to prevent overfishing and pollution
Importance of public engagements for long term success of conservation efforts
-National and Marine parks can attract thousands of tourists each year which increases money and awareness for the conservation effort
-Involving members of the local community in the management of protected areas can provide jobs and increase acceptance of the parks
-Some of the profits made from parks can be used to improve the health and education standards in the nearby communities to illustrate the benefits of having such areas nearby
Types of conservation in captivity
Zoos
Botanic gardens
Why zoos are important
-They are an invaluable resource for scientific research. Scientists are able to closely study animal’s genetics, behaviours and habitat needs
-They allow for captive breeding programmes so individuals of a species can be bred in order to release their off-springs into the wild
Problems with zoos and their role in conservation
-Captive breeding of small species populations can reduce genetic diversity
-Certain animal species will not breed in captivity
-Not all zoos can provide adequate habitats for animals with specific needs
An example of a species that zoos have successfully protected from extinction
The oryx is an antelope-like species that was saved from extinction and reintroduced into the wild in Africa thanks to zoos and captive breeding programmes
An example of a species that zoos have failed to conserve
Pandas have been in captive breeding programs for over 60 years and not a single panda has been reintroduced into the wild
How botanic gardens aid in species conservation
-Botanical gardens are the plant equivalent of zoos
-They use cuttings and seeds collected from the wild to establish a population of the endangered species in captivity. Methods of tissue culturing and cloning can also be used to obtain large numbers of plants from a small sample size
-The captive population can be used in the future for reintroduction into habitats where they have become rare
How research is a major role of botanic gardens
-They investigate reproduction and growth in different plant species so that they can be grown in captivity
-If the plants original habitat no longer exists they try to find suitable new habitats
How both zoos and botanical are instrumental to education
They help to raise awareness of vulnerable, endangered species and conservation efforts worldwide
How frozen zoos aid in conservation of species
-Frozen zoos store genetic material from animals (eggs, sperm, tissue samples etc) at very low temperatures (roughly -196 Celsius) so that they can be kept for a very long time
-Ideally samples are collected from different individuals of the same species to maintain the gene pool
-A large amount of genetic material can be stored in a relatively small space so in the future genetic materials from extinct animal species could be used to breed and reintroduce a species through IVF and genetic engineering
An example of a frozen zoo
The San Diego Zoo in the USA has frozen zoo facilities
How seed banks aid in the conservation of species
-A seed bank is a facility that conserves plant diversity by drying and storing seeds in a temperature controlled environment
-Usually, seeds of the same species are collected from different sites to maintain the gene pool. If the plant species goes extinct then the seeds can be used to grow them again
-Seeds can only be stored for so long. After a certain period of time the stored seeds are grown into plants and fresh seeds for storage are taken from those plants
An example of a seed bank
The Svalbard Global Seed Vault in Norway has almost 1 million species of plant seed. It is located in the Arctic Circle with ideal environmental conditions. Many organisations send seeds from crop plants to be stored there for safekeeping
What to do with plants that seeds can’t be frozen such as coffee and cocoa plants
In order to preserve the genetic diversity of these plants successive generations must be grown or tissue cultures taken
Conserving whole ecosystems is essential for
The long term survival of species. All of the conservation efforts made to stop a species going extinct is pointless if they don’t have a natural habitat to return to.
Endangered mammals tend to have
-small and isolated populations.
-small populations are prone to inbreeding and inbreeding depression
-in isolated populations individuals might find it harder to find suitable reproductive mates
Inbreeding depression
the reduction in fitness of a population due to breeding between closely related individuals and the resulting increased homozygosity
pros and cons of having large mammals being transported between zoos in captive breeding programs
Advantage: Humans were able to monitor the health of the mother and foetus
Disadvantage: It was highly expensive and unreliable as sometimes individuals would refuse to mate
The several solutions for inbreeding and the lack of reproductive mates in endangered mammals that science has come up with
IVF
Embryo transfer
Surrogacy
IVF (In vitro fertilization)
Involves the fertilization of an egg outside of the female body, for example in a test tube or petri dish
Procedure of IVF
-A needle is inserted into the female’s ovaries and eggs are extracted
-The eggs are kept in a culture medium for a short amount of time
-Male semen is mixed with the eggs so fertilization can occur
-Several zygotes form and develop into embryos
-The embryos are placed in a culture for several days
-The embryos are transferred either into the mother, or another female
The advantage that IVF has over natural mating
It allows humans to control and confirm fertilization of the embryo
Advantages of preforming embryo transfer for endangered species
-Since the population numbers of an endangered species are already very low each reproductive female is of very high value and importance
-Embryo transfer can be used to avoid the risks of pregnancy for the vulnerable female so that she can provide many eggs for multiple offspring
Procedure of embryo transfer
-An egg belonging to a female of the vulnerable species is fertilized by the sperm belonging to a male of the same species
-A zygote forms which develops into an embryo
-After fertilization, the embryo is taken from the uterus of the female and transferred to a surrogate female
-The embryo develops to full term and the offspring is born
surrogate
any female that becomes pregnant with the embryo from another female and carries the embryo to full term
Procedure of surrogacy
-Surrogate mothers require hormone treatment before they receive an embryo. The hormones ensure that her uterus is in the right condition for the embryo to embed
-There are multiple ways in which the embryo might have been conceived:
* Naturally
* Artificial insemination (semen from the male is injected into the uterus of the female)
* IVF
-A surrogate female can be the same or different species to the biological mother of the embryo. If it is a different species it needs to be closely related to ensure compatibility of the embryo and uterus
invasive species
A species that has moved into an ecosystem where it was previously unknown
How invasive species come to be
-Can occur naturally as a result of a species migrating or expanding their habitat
-Is usually caused by humans who have:
* Knowingly collected and traded species between countries via ships
* Unknowingly provided transport for invasive species to a new ecosystem
* Introduced alien species deliberately as biological control for pests
Relationship between evolution and invasive species and ecosystems
-The biological process of evolution often brings balance to an ecosystem
-Through evolution the environment strongly influences the adaptations that the species evolve to live in that environment
-A non-native invasive species will have evolved adaptations for survival in different environmental conditions so when they are introduced into the new ecosystem this can upset the balance
-In a new ecosystem invasive species will have little or none of the natural population controls that existed in their previous ecosystem; they will have no natural predators or competitors
Problems with invasive alien species
They are able to increase in number at a rapid rate affecting the processes within an ecosystem such as:
-Competition may occur between invasive species and native species that occupy a similar niche with the native species getting displaced or pushed to extinction. It could be competition for things such as prey, soil nutrients, light and space
-Many invasive species can be over successful predators causing a massive decline in their prey species
-Invasive species can introduce new diseases, to which the native species have no natural immunity
-The biodiversity of an ecosystem is negatively impacted which reduces its productivity
How humans can also feel the knock on effects of an invasive species taking over an ecosystem
-The spread of novel diseases and irritants of the skin / respiratory system directly affect human health
-The economy of a country can be severely impacted by the costs of trying to control invasive species and their negative effects
-In the past travel has been brought to a standstill by invasive species, with some plant species prone to blocking up waterways
IUCN stands for
The International Union for the Conservation of Nature
The International Union for the Conservation of Nature (IUCN)
the global authority on the status of the natural world and the measures needed to safeguard it
How the IUCN carry out the duty of assessing the conservation status of animal and plant species around the world
-The IUCN has their own classification system
-There are several different categories and levels that a species can fall into depending on their population numbers and the threats and risks to those populations
-Scientists use data and modelling to estimate which category each species should be in (such as extinct, extinct in the wild, critically endangered, endangered, vulnerable, near threatened and least concern)
CITES stands for
The Convention on International Trade in Endangered Species of Wild Flora and Fauna
The Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES)
-a global agreement that has been signed by over 150 countries
-aims is to control the trade of endangered species and their associated products, for example, elephants and their ivory tusks
CITES three appendices for endangered and vulnerable species
Appendix I : species that are endangered and face the greatest risk of extinction (for example, the red panda)
Appendix II: species that are not currently endangered or facing extinction, but will be unless trade is closely controlled (for example, the venus fly trap)
Appendix III: species included at request of the country that is regulating trade of the species and trying to prevent its overexploitation (for example, the two-toed sloth in Costa Rica)
trading regulations that apply to each appendix in CITES
For species in appendix I: all trade in the species and their associated products is banned
For species in appendix II: trade is only granted if an export permit has been issued by the involved countries
For species in appendix III: permits are required for regulated trade. Permits are easier to come by for species in this appendix
The several concerns about the efficacy of CITES listings
-When the trade of a certain endangered species becomes illegal, its price increases
-The increased economic value of the species can be a major incentive for people to break the law
