Eli5 : Why is biodiversity important ?



Eli5 : Why is biodiversity important ?

In: Biology

Genetic variation is necessary for evolution, less biodiversity, less genetic variation, the less likely organisms can evolve and survive environmental shifts.

Different plant and animal species are unlikely to be affected by the same problems, therefore if all of one plant species is killed due to a disease or change in climate, another species will take it’s place and the plant eating animals won’t starve.

It’s insurance against extinction. If a whole population is identical, it’s way more likely to be wiped out than a population that has a lot of variation, because the varied population will have a at least a few better adapted individuals immediately when something drastic happens.

If everything is genetically the same, then a virus or bacteria that becomes good at infecting one, becomes good at infecting all. We are seeing this with bananas. Bananas are a mutated plant and do not produce seed. Pretty much all banana plants everywhere on the earth were put there by a person who has taken a cutting from another plant’s roots. Therefore, there are only a handful of actual different banana plants in the world. When a virus mutates into something that hurts a banana plant, they all quickly become infected and perish. We have seen entire types of bananas become extinct in only a couple generations.
(Every once in a while, a plant will throwback to the seed bearing pods and from these we can get new banana types but it’s rare)

1) Heritage argument – we owe it to our descendants to preserve nature for them to experience. We can also consider ourselves to be a part of the earth’s ecosystem and have some obligation (as the dominant species) to protect and preserve it as good stewards.

2) Complexity and tipping point – The ecosystem is very complex and interrelated. We don’t fully understand the factors that control it. The fear is that there might be a tipping point, beyond which if we lose biodiversity, it sets off a large and potentially uncontrollable decline in the entire ecosystem. For example; your body can tolerate and fight off some germs, but at some point, your immune system is overwhelmed and you get sick. We don’t precisely KNOW when this threshold is reached so it is best not to venture there.

3) Knowledge argument. There is much that humans can and have learnt from nature. Humans learn by observing and the loss of biodiversity gives us less opportunity to study and understand more about the nature of the universe. There is still a lot that we can learn from nature (for example how could alien life develop, or how could we colonize a nearby planet, new medicines, new construction methods etc).

It’s same as what farmers do. They have multiple crops because:

-if one crop dies from disease or drought the others still live.
-by switching crops for each field every year the soil does not get “tired” (all same type nutrients get used up) and crop specific diseases don’t stick in the soil

Same argument could be made for biodiversity in general. As long as there is a good balance between species the surroundings can accommodate. If there is one species which is very dominant the environment gets killed off and therefore also the species.

In the Netherlands we had for example a nature reserve with too many horses in it. They ate all the grass and plants, a certain type of inedible plant took over because there was no competition, other animals died off because they lived off of other plants which were now pushed out by the inedible plants, etc.. the whole system collapses.

People here confusing biodiversity and genetic diversity within a species.

Genetic diversity helps a species overcome diseases and changes in environments.

Bio diversity is the number of different species. It is important because species are unique.

If a species dies out and becomes extinct, it is gone for good. No amount of evolution will bring it back. No amount of changing our ways and recycling will undo the damage.

Plants and animals that relied on the extinct species now have a new problem to deal with too.

Therefore it is important to maintain biodiversity because things can always bounce back.

Biodiversity and quality of air, water and soil go hand in hand. Imagine you have just 1 type of tree, animal and microbes. They can live from eachother until the point the environment has received too much waste from all 3. The one cant use the excretion products of the other, their soil gets satturated and our simple ecosystem will collapse under its own toxic excretions.

An ecosystem with thousands of different kind of species can buffer itself because each species produces/acquires different things. Over history there has been created a complex system with room for many many niches. Humans were born out of this established system. Once we start destroying the diversity (monoculture) conditions arent buffered, niches/habitats dissapear, biodiversity goes down and the quality of life nosedives.