PBS4 个月
The Current Mass Extinction
The typical rate of extinction differs for different groups of organisms. Mammals, for instance, have an average species "lifespan" from origination to extinction of about 1 million years ...
PBS1 年
The Current Mass Extinction
The typical rate of extinction differs for different groups of organisms. Mammals, for instance, have an average species "lifespan" from origination to extinction of about 1 million years ...