Thursday, June 11, 2009

Time Tree: The Timescale of Life

 
Check out the Time Tree website. You can type in any two species and find out when they diverged.

This is a great learning tool. Try it with Homo sapiens (that's us) and ....
Gallus gallus (chicken)
Danio rerio (some kind of fishy thing)
Strongylocentrotus purpuratus (purple sea urchin)
Drosophila melanogaster (fruit fly)
Caenorhabditis elegans (nematode)
Saccharomyces cerevisiae (baker's yeast)
Arabidopsis thaliana (flowering plant)
Plasmodium falciparum (protozoan, causes malaria)
Escherichia coli (bacterium)
Keeping in mind that the Cambrian explosion happened about 550 million years ago, try and guess when the lineage leading to these species diverged from the lineage leading to humans. Check your guess on the website.

Where you right? Why, or why not?


[Hat Tip: ERV]

3 comments :

  1. Here's where I show my abysmal ignorance. How come I tried the pair Homo sapiens and Bonellia viridis, and the time is about 800 million years? Did we really diverge before the Cambrian explosion?

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  2. Yes, molecular data based on differences in genomes point to divergences long before the Cambrian. It's not always clear how accurate they are, but at least the fossils show that they must have been diverged before the Cambrian too.

    Also larger animals from before (although a relatively short time) the cambrian explosion are known, search for "burgess shale"

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  3. Well anonymous, I know of various pre-Burgess formation (even Lagerstätten) but c'mon; 800 million years - and maybe a billion, try man and Charophyceae. Isn't there too much discrepancy between fossil and molecular dates?

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