It’s estimated that there were between 10,000 and 20,000 of us homo sapiens 50,000 years ago.
By year 1 (either C.E. or B.C.E, there was no year zero), we were around 10 million. That’s roughly the population of Nanjing, China’s 8th largest city.
Now we are a bit shy of 8 billion (7,970,000,000 and counting).
We’ve clearly been an extremely successful species, especially during the past few hundred years.
What might be called “success”, however, could also be called an “infestation”. That’s definitely how many other species would see it.
The numbers and chart above are from A Natural History of the Future: What the Laws of Biology Tell Us About the Destiny of the Human Species by ecologist Rob Dunn. The author, as you might expect, sees problems ahead, including the climate crisis and antibiotic resistance. Life will flourish. Us, not so much.