IB SL/HL Biology A4 Conservation of Biodiversity

What are the three levels of biodiversity?

What are the three levels of biodiversity?

Genetic biodiversity, species biodiversity, and ecosystem diversity.

What is ecosystem diversity?

The variety of ecosystems, both terrestrial and aquatic, found in a given geographical area.

A function of community and habitat diversity.

What is genetic diversity?

The diversity seen in the genes (alleles) within a population of a species.

What is species diversity?

The number and types of organisms that existed during a specific amount of time.

What is biodiversity?

The variety of life in all its forms, levels and combinations.

Which two factors does species diversity depend on?

Species richness: a measure of biodiversity that is the number of different species in an ecological community, landscape, or region at a given time.

Species eveness: a measure of the relative abundance of different species in a given area or community.

What causes slight variation within a species?

Variations are caused by variations in the genes.

What do mutations result in?

In slightly different versions of the same genes. These versions are called alleles.

What is a mutation?

A change in the sequence of genetic material.

Why is genetic diversity important?

A higher genetic variation increases the probability of alleles in the gene pool that allow an organism to adapt to changing environmental conditions.

What does evidence from fossils suggest?

They are indicators of the diversity of species that existed in the past and are used to understand the changes in biodiversity over geological timelines.

What does current evidence from fossils also suggest?

It suggests that there are currently more species alive on Earth today than at any time in the past.

What is the sixth mass extinction a result of?

A result of human activity.

The sixth mass extinction is what type of species extinction?

Anthropogenic species extinction.

What is anthropogenic speciation caused by (list some specific reasons)?

Overexploitation due to overhunting or overharvesting,

habitat loss due to human activity, introduction of invasive or alien species outcompeting native species, habitat degradation due to pollution, and climate change.

(LONGER ASNWER) Outline the North Island giant moas as an example of the loss of terrestrial megafauna.

Fossil studies shows they underwent anthropogenic extinction. The North Island giant moas were tall, slender birds with long, shaggy, hair-like feathers. The islands of New Zealand surrounded by water remained isolated. When the island was colonised by Polynesians, the large birds underwent overexploitation, rats ate their eggs, and diseases brought by humans extinguished them.

(LONGER ANSWER) Outline the Caribbean monk seals as an example of the loss of a marine species.

Fishermen killed hundreds of seals to fuel oil lamps, grease machinery, for their blubber and other products. Overfishing in the waters where they lived, meant that these animals fell short of food sources like fish and molluscs — deprived of their natural food many individuals in an already declining population starved to death.

Outline one other species that has gone extinct from an area that is familiar to you (KOGNITY EXAMPLE).

The splendid poison frogs, once widespread in the humid forests of Panama, were declared extinct in 2020.

Reduction in their geographic range due to activities such as logging, conversion of forests for agriculture and expansion of urban area, trafficked as part of the 'pet' trade, outbreak of a fungal disease that had been ravaging amphibian populations in the tropics, all led to extinction of the frogs.

(LONGER ANSWER) Outline the fall of the dipterocarp forests case study.

Dipterocarps are keystone species, essential for ecosystem services and functions. They are highly prized for their timber and are extensively felled. Another threat is clearing of the forests for palm oil plantations, this has led to deforestation. Often, to clear the forests, stretches are burned down releasing carbon into the atmosphere. Endangered animals such as elephants and orangutans are losing their homes. Thus, destruction of the dipterocarp forests has far-reaching consequences, not only for the life they support but also for humans.

(LONGER ANSWER) Outline the loss of ecosystem from an area that is familiar to you (KOGNITY EXAMPLE — THE DYING REEFS).

Reefs provide a myriad of benefits; sustain food webs, provide food for people, sources for new medicines, protect the coastline from erosion and storms. The coral reefs are under great stress and many species of corals are endangered. Threats include; pollution, hot water from power plants, rubbish, plastic, oil spills, destructive fishing activities like overfishing unsustainable tourism where careless divers damage coral reefs. Global warming has bleached the reefs.

(FOR KOGNITY CASE STUDY) Identify the immediate effect of cutting of a mixed dipterocarp forest on a nearby coral reef.

Greater soil erosion and increased runoff of sediment, nutrients and pollutants.

What isthe IPBES?

An intergovernmental organisation established by the UN to assess and strengthen biodiversity and ecosystem services. It states that over a million plant and animal species are threatened with extinctio.

What is citizen science?

Research conducted with the help of the general population who are not professional scientists. This brings unique methodological concerns.

Why are biodiveristy surveys important?

They provide valuable information to decision-makers regarding the use of resources and species conservation.

Why are biodiveristy surveys repeated?

Repeated surveys give information about species richness and evenness, which helps experts understand the changes taking place within a community — to gain a better understanding of the biodiversity.

What are the causes of the current biodiversity crisis?

The rapid increase in population growth, hunting and other forms of over-exploitation; urbanization; deforestation and clearance of land for agriculture with consequent loss of natural habitat; pollution and spread of pests, diseases and invasive alien species due to global transport are all causes of biodiversity loss.

How does population growth impact biodiversity?

As the population grows, the demand increases for resources including food, water and space. This increasing pressure for resources leads to overexploitation of natural resources and habitat destruction.

Outline hunting and overexploitation.

Overexploitation is the overuse of natural resources at rates faster than they can be replenished.

Overhunting is the excessive and unsustainable hunting of a species, often leading to a significant decline in its population, potential extinction.

Outline the destruction of habitats.

As the demand for space increases, more and more of the natural habitats are lost. When habitats change drastically, species adapted to life in these habitats can no longer survive there.

Outline urbanization on the biodiversity crisis.

Urbanisation encroaches on existing natural habitats and can fragment them into smaller habitats which restricts animal mobility, reduces access to resources and increases the risk of extinction.

Outline pollution.

The introduction of substances into the environment that adversely affect the environment. Pollution can take the form of air, water and land pollution.

What is in situ conservation?

A way of conserving animals and plants in their natural habitats while maintaining the original biodiversity of the area. It is less disruptive and more cost-efficient.

What is ex situ conservation?

Plants and animals are conserved outside their natural habitats. In some species the numbers are too small to sustain the species or risk of poaching is high so scientists establish gene banks to store 'biodiversity'.

What is a gene bank?

It involves the storage of germplasm (or genetic resources). These collections of living material include animals in zoos, plants in botanical gardens, seeds, sperms, eggs, pollen, DNA collections and so on.

What is rewilding?

The process of restoring and reintroducing natural ecosystems and species to areas where they have been lost or significantly altered.

Outline the reclamation of degraded ecosystems.

Unsustainable human activity often causes a degradation of the land and water. The loss could be due to erosion of the soil, deforestation, salination and so on. Land restoration strategies look at recovering and reclaiming degraded ecosystems.

How are EDGE species selected to be conserved?

The species are selected according to their;

Evolutionary Distinctiveness (ED) score.

Globally Endangered (GE) score.

What is ED score?

The ED score is determined by the position of the animal on the phylogenetic tree. ED scores are higher for species that are evolutionarily more distinct or have fewer closer relatives.

What is GE score?

This is calculated based on the IUCN Red List. The more endangered the species, the higher the GE score. For example, critically endangered species have a higher score than endangered species or vulnerable species.

*What is the rationale behind focusing conservation efforts on EDGE species?

Threatened species that represent a significant amount of unique evolutionary history.

They represent a unique and irreplaceable part of the world's natural heritage.