Da li su životinje divlje ili mi?

[Nemoguća Могућност]

pa ne bas
mnogo je kataklizmi bilo bez ljudskog uticaja
mi smo preponosni na sebe
i pridajemo si sami sebi preveliku vaznost
dok ne dodje belaj, onda instantno naucimo koliko zapravo nismo bitni u grand scheme of the things

There have been five mass extinctions in Earth's history
https://ourworldindata.org/mass-extinctions​

What is a mass extinction?​

First, we must be clear on what we mean by "mass extinction". Extinctions are a normal part of evolution: they occur naturally and periodically over time.

There’s a natural background rate to the timing and frequency of extinctions: 10% of species are lost every million years, 30% every 10 million years, and 65% every 100 million years.

It would be wrong to assume that species going extinct is out of line with what we would expect. Evolution occurs through the balance of extinction – the end of species – and speciation – the creation of new ones.

Extinctions occur periodically at what we would call the "background rate". We can therefore identify periods of history when extinctions were happening much faster than this background rate – this would tell us that there was an additional environmental or ecological pressure creating more extinctions than we would expect.

However, mass extinctions are periods with much higher extinction rates than normal. They are defined by both magnitude and rate. Magnitude is the percentage of species that are lost. Rate is how quickly this happens. These metrics are inevitably linked, but we need both to qualify as a mass extinction.

In a mass extinction, at least 75% of species go extinct within a relatively (by geological standard) short period of time. Typically less than two million years.

The five mass extinctions​

There have been five mass extinction events in Earth’s history, at least since 500 million years ago. We know very little about extinction events in the Precambrian and early Cambrian earlier, which predate this. These are called the "Big Five" for obvious reasons.

In the chart, we see the timing of events in Earth’s history. It shows the changing extinction rate (measured as the number of families that went extinct per million years). Again, note that this number was never zero: background extinction rates were low – typically less than 5 families per million years – but ever-present.

 

[Nemoguća Могућност]

sva sreća pa zivimo u veštačkim pećinama i retko zalazimo u pravu prirodu