• Question: How can starfish be related to us humans?

    Asked by jf10 to Common starfish on 14 Nov 2017.
    • Photo: Common Starfish

      Common Starfish answered on 14 Nov 2017:

      Excellent question.

      All animals on earth are descended from a common ancestor so a family tree can be produced that shows the relationships of all the animals types. If you look at this picture:

      you will see that there are two major branches in the animal kingdom – the deuterostomes and the protostomes.

      Humans and other vertebrates are deuterostomes and so are starfish and other echinoderms. Most invertebrates (e.g. insects, nematodes, molluscs) are protostomes.

      A lot of research is done on insects like the fruit-fly Drosophila but insects are quite distantly related to vertebrates.

      Starfish and other echinoderms occupy an “intermediate” position between insects and vertebrates so they provide “missing links” when we investigate the evolution of genes and genomes.

      Hope that makes sense. Feel free to ask another question if anything wasn’t clear.