TIME IMMEMORIAL. I worked through the statistics in yesterday’s post because I found it surprising that about 80% of plant species in Britain have been present “since time immemorial”.
I had posted, for example, here, about how 75% of the ancestors of the British population came to Britain as hunter-gatherers between 15,000 and 7000 years ago—again “time immemorial”.
There seems to have been rather a small amount of change over thousands of years.