Maintaining biodiversity

Since life on earth began over 3 billion years ago biodiversity has been increasing due to evolution.

The development of the Human species has caused problems.

Most species have adapted to survive in their environment.

Humans develop their environment to suit themselves.

By changing the environment we put extra pressures on other species, squeezing them to the edge of extinction.

The number of species on earth has currently been estimated at 1.5 million but the number may be larger

Coral reefs provide great biodiversity for aquatic life

Rainforests contain an enormous number of plant and animal and fungal species, many of which remain undiscovered.

We alter the environment to suit ourselves

Our population doesn’t stabilize in accordance with Darwin’s theory! We are multiplying out of control.

We are using more of the earth’s resources to support our burgeoning population

We destroy the habitats of other species to sustain our species (e.g. cutting down rainforests for wood and to plant crops)

Habitats/biodiversity are lost The organisms that rely on

them face extinction.

Extinction occurs when the last living member of a species dies and the species ceases to exist

Sometimes extinction occurs due to natural changes, as with the dinosaurs.

Human activity over the past 300 years has accelerated extinction rates, however.

Economic Reasons:

Ecosystems provide valuable goods and services. E.g. fish and timber, we can use them carefully, giving them time to recover or greedily destroy them indiscriminately.

They help purify our water, produce rich soils and reduce carbon dioxide which threatens to cause flooding of important agricultural areas due to global warming

$250 billion is lost each year due to habitat destruction

10 square miles of rainforest disappear every minute.

Ecological Reasons:

Keystone species are important in the regulation of ecosystems, e.g. kelp forests in the North Pacific began to disappear when the sea otter was overhunted by man. This was because sea otters hunt sea urchins, with reduced sea otters urchins thrived and over grazed the kelp forests.

Laws to prevent otter hunting restored the balance.

Pacific Kelp Forest

Sea Otters, a keystone species

Ethical Reasons: It may be argued that Humans have been acting irresponsibly towards other species. Many species such as the great Auk and Dodo have become extinct due to human activity, and over 20,000 species of plant and animal are currently facing the same fate.

Aesthetic Reasons: Wild places such as Coral Atols and African Savannah are very beautiful places that people enjoy. Destroying them for economic gain seems like vandalism.

It seems only correct that these things should be preserved for future generations to enjoy as we have.

Our diet is very limited compared to our ancestors who ate any wild food that was edible.

Make a list of the species you ate over the last couple of days (you will find it was surprisingly limited) e.g. Potato and Chicken.

It is more economic for a farmer to farm massive field of maize, rice, wheat potatoes etc. which provide high yield and people are familiar with than to farm hundreds of tiny fields of varied crops with a less certain chance of sale (this is sometimes called economies of scale)

Crops commonly eaten are potatoes, wheat and Rice.

If a major disease were to hit one of these a third of the world would probably starve.

The Irish potato famine is a historic example, people were so desperate there were cases of parents eating dead children.

There are many plants and animals which provide high energy value which are shunned due to ignorance.

The large reserve of genetic information of these alternative crops will be lost if rare varieties or unused wild crops are allowed to die out.

Lincoln Longwool, limited to 30 flocks

Old smokehouse, 25 trees remaining

Some crops such as potatoes need plenty of water to grow to a significant size. UK farmers have already found potato sizes diminishing.

New crops which resist drought need to be developed.

This could include varying the genome of our current wheat plants by cross breeding them with hardy wild grasses

In places that are becoming more humid, Anopheles mosquitoes are likely to increase

Fungal spores that threaten wheat such as ‘black stem rust’ are overcoming the standard genetic variety.

Mankind has long relied on plants for medicine.

Plants contain complex chemicals produced quickly by the plants varied metabolism.

Especially in rainforests there may be thousands of unknown plants which could provide cures to diseases such as cancers and neurological disorders

These could be blindly destroyed without conservation of habitats

Solanum dulcamara