For example, Jordan Peterson claims that human and lobsters have a common ancestor X million year ago. I wonder, how does he know it?
I'd be so delighted to visit a website, where I could select two currently existing species and it'd show me how many years ago they had had a common ancestor. Does anything like this exist? Do we at least have a database, so I, as a web programmer, could create this kind of website?
TimeTree [http://www.timetree.org] is one site that allows you to look at times from divergence of various taxa. Their FAQ describes how they calculate the times by pointing to this paper: Tree of Life Reveals Clock-Like Speciation and Diversification, but in general they used standard molecular clock approaches. You ask about downloading their database: they say
The TimeTree Database data is currently not available for download. Methods for making these data available in the future are currently under discussion.
