This month’s Creature Feature is about some curious interactions between parent and baby terns that my undergrad colleague Rachel Moon and I observed on the beach in St. Augustine, FL, about a month ago.
It’s based on the following pieces of research, primarily:
Here is my latest for the column, on a flower I came across in the Kanapaha Botanical Garden in Gainesville, FL. The piece got quite a bit shorter between writing and publishing, so I’m including a longer version below.
From the vantage point of my privileged 21st century life, filled with plentiful food and easily acquired medicine, I think back to the lives of our earliest human ancestors with terror and awe. How did they figure out what they could and couldn’t eat, what would hurt and what would heal? Walking through a cornfield today, it’s easy to see that corn is meant to be eaten. But thousands of years ago, corn didn’t grow in neat rows or bear such inviting kernels. Ancestral maize seeds were tiny, brown, and hard, borne on plants that look, to the untrained eye, like any other grass. But our forefathers still recognized these plants as sources of nutrition. Or take coffee. How long, how bitter was the process of figuring out that coffee berries must be washed, cleaned, dried, roasted, ground, and brewed with boiling water before yielding a liquid that some still find unpalatable?
When it comes to medicinal plants, the risks and rewards of trial-and-error are magnified. In a quite literal embodiment of the cliché that what doesn’t kill us makes us stronger, many plant extracts that in small quantities can save our lives, will, in larger quantities, cause our demise. But when I came across the Glory Lily in a botanical garden a few days ago, the thought that this plant could help or harm me didn’t even cross my mind. I stopped to look at it only because of its pretty flowers.
Glory lilies have been used by people across the world to cure all manner of ills, from haemorrhoids to head-lice. But its usefulness is tied to its deadliness—many of the uses that humans found for glory lilies involved killing something, be they parasitic worms or other people. This plant’s potency, serving medicinal or murderous ends, lies in the chemical colchicine. Colchicine interferes with important proteins, called tubulins, that make up our cells’ equivalents of bones and arteries.
The glory lily probably produces colchicine for protection, to dissuade animals, all of whose cells contain tubulins, from eating it. But a glory lily doesn’t benefit from scaring away all animals. In fact, its showy flowers exist solely to attract certain animals, which will transfer its pollen to other glory lily flowers and allow the plants to reproduce. And we can tell from its flowers that attracting pollinators is crucial to the glory lily. The combination of the flowers’ downward facing male parts (the anthers covered in yellow pollen) and a sharp upward turn in its female parts (the green style tube ending in three stigmas) make it near-impossible for pollen to fall from a flower’s anthers onto its own stigmas, preventing it from fertilizing itself (see the picture below for the clearest view). Glory lilies thus depend on outside assistance to reproduce, and the flowers’ gorgeous colours and form must play a role in enticing animals to help.
Some neuroscientists think that similarities in our brains might explain why flowers are attractive to birds, bees, and me. Perhaps our brains see beauty in the contrast of the glory lily flowers’ colours against a green background, perhaps from its symmetry. If I had lived five thousand years ago, I doubt my brain could have deduced if the glory lily would kill or cure me, but I hope that it would still have found these fiery flowers beautiful.
[The piece is based on the following:
Selvarasu, A. and Kandhasamy, R. 2012. Reproductive biology of Gloriosa superba. Open Access Journal of Medicinal and Aromatic Plants 3: 5-11
Maroyi, A. and van der Maesen, L.J.G.. 2011. Gloriosa superba L. (family Colchicaceae): remedy or poison? Journal of Medicinal Plants Research 5: 6112-6121.
Kavithamani, D., Umadevi. M. and Geetha, S. 2013. A review on Gloriosa superba as a medicinal plant. Indian Journal of Research in Pharmacy and Biotechnology 1: 554-557
Lindstrom, E.W. 1926. An unusual adaptation for cross-pollination. Journal of Heredity 17: 233-234
Also, the ideas on perceptions of beauty across animals that are briefly alluded to at the end of the piece come from V.S. Ramachandran’s work on the subject.]
Here is my latest piece for the Creature Feature column, on tent caterpillars. A couple of corrections/clarifications:
Horses are grazers, not browsers, so the sentence that reads “horses…swallowed a large number of tent caterpillars along with mouthfuls of leaves” is incorrect, because horses are more likely to eat mouthfuls of grass than mouthfuls of leaves.
The subheading for this piece is slightly misleading, because “truly social” (or “eusocial“) is a strictly defined biological term referring to sociality that includes overlapping generations within a colony, division of labour, cooperative brood care, and sterility of the workers in a colony. Tent caterpillars are not eusocial, but I’m arguing that their version of sociality is just as interesting.
The piece is based on the following pieces of research:
A popular science summary by James T. Costa, titled “Caterpillars as social insects” [PDF].
My latest piece for the Creature Feature column is on two creatures I’ve seen recently on the University of Florida campus, the large colony of Mexican Free Tailed Bats and a single Megarhyssa wasp. Both rely on sensing sound in interesting ways, for survival and reproduction.
I wanted to write more about the process by which these wasps locate the wood-boring insects in which they lay their eggs, but couldn’t really find too much information. But thanks to Dr. Laura Timms, who shared her expertise with me, I now know a lot more about this–it’s complicated, and involves both sensing both chemicals and sounds, and will be the subject of a future blogpost. In the meanwhile, check out these fantastic videos of a Megarhyssa wasp laying her eggs.
Finally, here are the references that my piece is based on:
Here’s this month’s Creature Feature, which begins with the electric blue tails of skinks and ends with limbless lizards. It’s based on these two papers about why skinks have blue tails (1, 2) by William Cooper and Laurie Vitt, as well as this paper on the evolution of limblessness in lizards by John Weins and colleagues.
And here is one of my favourite lizards, the almost-limbless grass lizard.
Also, many thanks to my colleague from college, Geoffrey Giller, for contributing a photograph to the piece! Go follow him on Twitter @GeoffreyGiller and check out his work as a science writer and photographer at his website.
My new piece for Creature Feature is about two snakes that are a looming presence in my life in the field: the saw-scaled viper and the cottonmouth. The piece talks about research by Harvey Lillywhite and his lab on the unusual feeding biology of island cottonmouths, and also a paper, Barlow et al. 2009, on the coevolution of diet and venom composition in saw-scaled vipers.
I’ve gotten into the bad habit of not posting links to the scientific publications upon which my Creature Feature columns are based. Unfortunately, the length and format of the column are incompatible with including references in the pieces themselves, but I’ve been meaning to post links on my blog. My only new year’s resolution is to start sharing these links, so here’s everything for last year! Many of these links are pay-walled; email me if you want a PDF of anything in particular.