Modelling eco-systems with Google search tool

August 7, 2008

predators and prey

The Google PageRank formula can be used to model changes to the structure of food webs in an eco-system.

Eco-systems often contain many different species which depend on each other in complex ways. Working out how population changes and extinctions affect the food web is difficult. But finding out which species are key predators and prey in these webs is vital if species or eco-systems are to be protected.

Nature reports how Google tool identifies linchpin species (2008-08-06).

Stefano Allesina is working on the reverse engineering of ecological networks, to work out “extinction risks”. He is using a modified version of Google’s Page Rank™ algorithm to model the relationships between species.

PageRankanalyses the connections between web pages to discover the importance of the pages. Allesina’s modifications allow him to model the importance of species by calculating their connectivity.

I wonder about how well the modelling works for eco-systems where the species – never mind their relationships – aren’t known in detail or even at all…?

Another Nature news item on the same day indicates that there are lots of viruses in the oceans which haven’t been discovered, and these viruses may play an important part in the life cycle of plankton (‘Virophage’ suggests viruses are alive).


3 Responses to “Modelling eco-systems with Google search tool”

  1. Peter Manson Says:

    Did you know that your links to Nature are to subscription-only data? Are you getting a cut from Nature for promoting their paid-for service? 🙂

  2. infomancie Says:

    I didn’t know. And I don’t get. 😦

    But I do (now) know why…

    “Over 50% of our news is free for 4 days from publication.”

    They want people to pay for their hard work reporting!

  3. Peter Manson Says:

    Maybe you should! If you’re directing traffic their way and developing interest in the articles for them, then its only fair you should get a cut of what is quite a high charge they make.

    Their claims on charging look quite spurious – they already cover costs of reporting to collect and prepare the content with the printed versions, and show no signs of dropping printed circulation, so the charge for electronic access is almost totally pure profit. I’ve no objection to reasonable charging, but GBP6.25 for a one month subscription or US$8 for a single article looks unreasonable.

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