 IT'S HARD TO IMAGINE a more effective way to
consign a book to the remainder bin: give it a drab off-white cover bearing sketches of birds' heads, an impossibly dull title that begs to be misfiled under 'birds' instead of 'science', and
round it off with those untrimmed pages that are supposed to evoke the charm of nineteenth century book binding but which actually suggest poor quality control. On presentation alone this one
ought to go extinct pretty quickly.
The Beak of The Finch is, however, an interesting book. It's about evolution and more specifically about the finer points of speciation. The central question - how can
separate species form without geographical isolation - is explored through the recent history of Darwin's Finches in the Galapagos Islands. The book reports and analyses the work of Rosemary and Peter
Grant, who have spent more than twenty years following the ebb and flow of finches on a single island. During this time they have individually tagged, weighed and measured almost 19,000 birds - the entire
population of finches across fifty generations. The Grants discovered that natural selection never sleeps and the boundaries between species of Darwin's finches are being relentlessly
shoved this way and that by upheavals in the adaptive landscape. During their stay the Grants witnessed two major selection events and recorded the most complete set of measurements ever taken of evolution in
action. From their measurements they have drawn new insights into the speed of evolution, which prompts the book's subtitle 'Evolution In Real Time' (perhaps this would have made for a better title!) The
Grants have also drawn conclusions about specific mechanisms of natural selection, including the importance of hybridization as a source of diversity.
WHAT I LIKE about this book is that it's easy to read. The arguments don't get unnecessarily technical or involved (but the references are there if you want them) and it really conveys well the idea that
'species' is really a poor concept because the boundaries are constantly shifting. It's also a good example of evolutionary biology as 'hard science'. |
