01 February 2011

Carnival of Evolution No. 32

Correction, 11:25h: I've just been informed that the fish in the photograph below are not swordtails, but guppies. Burned again by Flickr taxonomy! The real Darwin would've got it right, I'm sure.

The Carnival of Evolution is a monthly collection of online writing about evolutionary biology and its cultural and political implications, hosted by a different blogger every month. Today, Denim and Tweed hosts CoE for the first time. Since Charles Darwin's birthday is this month (only 12 shopping days left!), I thought it might be appropriate to imagine what Darwin himself might have to say about this month's posts. Share and enjoy!

Photo via WikiMedia Commons.
Down. Bromley. Kent.
Febr. 1, 2011

My dear Hooker,

I was grateful for your very kind wishes; and for the book about the Anoles of the West Indes, which I expect I shall read with much enjoyment. The merest thought of an approaching 202nd birthday makes me feel the need for another trip to Malvern; but I do find some relief in my reading, of which I must needs do more every day it seems, only to keep abreast of the latest work. My great-grandson presented me last month with an i-Pad, a charming device; I can now consult the "web-logs" in the garden, when it is pleasant.

And there is such a lot of reading to do! It seems I read constantly about work extending the ideas I first proposed more than 150 years ago; it is gratifying, and rather humbling, to see what has grown from my little "abstract." And dear old Wallace's, of course. (Have you heard from Wallace recently? The last I knew of him, he was departing on that expedition with Greenpeace; but that was more than a year ago.)

Once I suspected my thoughts upon the origins of species would soon be only of interest to students of history and philosophy, but every-where I look I find someone else building upon my ideas.

For instance, experimentation has recently shown that more diverse communities of microbes use resources with greater efficiency, which extends my own simple trials with grasses on a small plot of ground. I am quite interested in the ongoing study of such interactions between species; there has been much interesting work on the co-evolution of hosts and their beneficial symbiotes, in which it is debated whether hosts may control their symbiotes without the need of punishments. And I recently saw that some species of citrus can attract parasitic worms to drive off weevil larvae.

I was also charmed to discover that butterflies of the species Eurybia lycisca, have evolved elaborately long tongues, long enough to take nectar without pollinizing; an unfortunate development for the flowers they visit! And I have recently seen a delightful study of the leaping of Blenniid fishes, supported by many moving pictures; and the very interesting findings of separated forms of the Clouded Leopard in Borneo and Sumatra.

(Here is a charming moving picture of the Clouded Leopard. What a blessing You-Tube is for the stay-at-home naturalist!)



Which is not to say that I think all developments from my theories are sound; you may have read about the idea that women's tears are modified to save them from molestation, which seems to me curious indeed. I have also seen some very odd speculations upon the morphology of human beings in the distant future. I do not understand why the form should be arboreal. It may be worth recalling, in this context, that Humankind is only one twig in the evolutionary tree of the Apes.

Still more interesting to me is discovering the ways in which I was mistaken (embarrassing as they often are) and facts I was unable to percieve at the time of first writing. For instance, this extensive essay about Mosaic Evolution, or what I might call the Independent Modification of Parts; which evidently has its roots in Lamarckism. We may have been too harsh on the good Chevalier. Equally as interesting is this disquisition upon conditions in which Natural Selection may not lead to modification of descendants. Of course a lack of adaptation might be just as informative as the process of adaptative modification itself!

Of course the experiments of Gregor Mendel were an important improvement to what little understanding I mustered in The Origin; some suggest that now that Mendel's thinking is over-simple, but it retains much power I feel. The study of living species is so very complicated! We must keep watch not only upon D.N.A. but the myriad complications of its translation to form the structures of the body, and even the duplication of genic code to originate new structures. The greater understanding we have gained since I first concieved of Natural Selection promises to continue improving the condition of humanity; I read, for example, that we may manipulate adaptations lengthen life at a cost to fecundity in order to breed more productive crops.

I must admit that I badly underestimated the role of chance and mutation in the descent of species; especially the degree to which it could allow imperfection to persist, even costly mis-folding of protein molecules. And yet chance changes may have profound consequences for the future of a species, much as my lucky chance to join the crew of the Beagle started me as a naturalist.


A pair of sword-tails guppies. Photo by Alice Chaos.
I have read recently also of several challenges to my original thoughts on Selection in Relation to Sex; experimentation has found, for example that the sexual ornaments of Xiphophorus sword-tailed fishes, do not hamper the males' abilities to escape danger, which suggests they carry no great cost.

And of course it seems that there have always been persons who object to the idea that we might share kinship with apes and even sessile cirripedes; but fortuitously they seem not to have come up with any particularly novel arguments since 1859. And we may even use Natural Selection to explain the religions that deny the common descent; I suspect that social influences are greatly to blame.

With learned discussion so abundant and easy to find, it is truly a wonder that ignorance and misinformation persist; if only more people did their researches with proper care!

Yours very sincerely,

Thanks to everyone who contributed to this month's Carnival! Want to submit posts for next month? Go to the BlogCarnivals form, or check out the list of past and future hosts at the carnival index page. Just as importantly, the Carnival needs hosts starting next month! If you'd like to host the Carnival, CoE overlord Bjørn Østman wants you to e-mail him right now.

No comments:

Post a Comment