biodiversity and natural resources

Biodiversity

The difference between individuals within a habitat/ecosystem between populations of the same type of species, communities and ecosystems

Factor when measuring genetic biodiversity

Species richness

Species evenness

High genetic diversity (Large gene pool)

Possess a variety of alleles to be resilient to changes in the environment/selection pressures

Low genetic diversity (small gene pool)

Small variety of alleles so more susceptible to extinction by introduction of a new disease or change in the environment

Is the number of different species found in a specific area

Species evenness

A measure of the reactive abundance of different species

Why is it important to measure both species richness and genetic diversity to give a full picture of biodiversity?

Biodiversity takes into account both the number of species and the amount of genetic diversity within species

Using both measures it is easier to identify area of high concern for conservation

Species diversity

Relates to the number of the different species and the number of individuals of each species within any one community

A number of objective measures have been created in order to measure species diversity

Low species diversity suggests

Relatively few successful species in the habitat

The environment is quite stressful with relatively few ecological niches and only a few organisms are really well adapted to that environment

Food webs which are relatively simple

Change in the environment would probably have quite serious effects

High species diversity suggests

A greater number of successful species and a more stable ecosystem

More ecological niches are available and the environment is less likely to be hostile

Complex food webs

Environmental change is less likely to be damaging to the ecosystem as a whole

Ecosystem (habitat) diversity

This is the diversity of habitats or ecosystems within an area

A region possessing a wide variety of habitats is preferable and will include a much greater diversity of species then one in which there are few habitats

Genetic diversity

This is the genetic variability of a species. Genetic diversity can be measured directly by genetic fingerprinting or indirectly by observing differences in the physical features of the organisms within the population

Genetic fingerprinting of individuals within cheetah populations had indicated very little genetic variability

Lack of genetic diversity it problematic and it would indicate a species would not have sufficient adaptability and may not be able to survive an environmental hazard

Traditional definition of a species

A group of organisms that are physically physiologically and behaviourally similar, they can breed to produce fertile offspring

Reproductive species

If two individuals from different populations mate to produce fertile offspring there is said to be a gene flow from parent to offspring

Ecological species

Share the same ecological niche

Ecological niche

Role of the organism in its environment

Recognition species

Based on their fertilisation system - mating calls, songs, dances, breading, times, seasons

Genetic species

Based on similarities and differences in the DNA this is called molecular phylogeny

Reasons for classification

Identification of new species

Identify common ancestry

Asses now closely related a species is

Acronym for remembering binomial nomenclature

Sushi good for order came phillip king

Three domains

Eukarya

Eubacteria

Archea

Eukarya elements

Cell type - eukaryotic

Histones - have histones

Introns - most contain introns

Ribosome size - 80S ribosome

Cell wall composition - not always present - plants; cellulose - fungl; chitin

Cell membrane composition - ester linked lipids with proteins (straight chain)

Eubacteria characteristics

Cell type - prokaryotic

Histones - no histones

Introns - no introns

Ribosome size - 70S ribosome

Cell wall composition - made of peptidoglycan

Cell membrane composition - ester linked lipids with D-glycerol (straight chain)

Archaea characteristics

Cell type - prokaryotic

Histones - have proteins similar to histones

Introns - some introns

Ribosome size - 70S ribosome

Cell wall composition - made of protein (lack of peptidoglycan)

Cell membrane composition - ester linked lipids with L-Glycerol (brainched chain)

Molecular phylogeny

Technique which analyses the structure or presence of chemicals and DNA sequence of a gene

Ecology

Study of interactions between all the living organism in area with their environment

Micro-habitat

A small area within a habitat

Population

A group of organisms of the same species, living and breeding in a particular niche in a habitat

Community

Organisms living with each other in a specific area

Anatomical adaptations

Physical

Differences in the internal or external structure of the organism

Physiological adaptations

Differences in the biochemical pathways of an organism

Behavioural adaptations

Differences in the behaviour of an organism

Survival of the fittest

Sexual reproduction results in more offspring that environment can support

Inherited variation expressed in phenotypes of offspring

Struggle for survival due to selection pressures

Healthiest, strongest, fastest, best insulated rabbits survive and breed

Summary of natural selection

1. Random mutation + new allele

2. New allele makes organism better suited to its environment

3. It survives and breeds successfully

4. New allele passes onto offspring

Founder effect

Occasionally a small group of individuals may break away or become separated from a parent population

The ‘founding’ population is only made up of a small number of individuals, inbreeding may be a problem if individuals are closely related

The ‘founding’ population may have a change in allelic frequency from the parent population

The colonising population may evolve quite differently from the original population especially if the environment is different

Certain alleles may be eliminated completely, resulting in a reduction in the size of the gene pool and loss of genetic diversity

Genetic bottleneck

Ecological events may reduce population sizes dramatically

These disasters were unselective

The gene pool of the small surviving populations is unlikely to be representative of the original population

By chance alleles may be overrepresented among survivors, some may be eliminated completely

The allelic frequency of the surviving population will be different to the original population

Directional selection

In directional selection, one extreme of the trait distribution experiences selection against it

The result is that the populations trait distribution shifts toward the other extreme

In the case of such selection the mean population graph shifts

Diversifying selection

Increases diversity, may result in speciation due to geographical isolation or varied selection pressures

Balancing selection

Variety is maintained as an allele is kept in a population although it would appear to be disadvantageous

In this condition, the recessive allele can be an advantage in carriers as it protects against malaria

This is known as hybrid vigour

Gene pool

All the alleles of all the enemies in a population at one time

Allelic frequency

How often the allele occurs in a population an allelic frequency of 1=1 - 100% of the population have that allele

Things that must occur for the hardy and weinberg

No mutations (no new alleles)

Large population

Random selection of mates

Isolation of population

No selection (no one allele advantageous over the other)