Literature Review: Milkweed Insects

by Carl Strang

This week’s peek at the scientific literature is a recent study published in the journal Science. My source is an article about that study in the science review site ScienceDaily.

Y. Zhen, M. L. Aardema, E. M. Medina, M. Schumer, P. Andolfatto. Parallel Molecular Evolution in an Herbivore Community. Science, 2012; 337 (6102): 1634 DOI: 10.1126/science.1226630

They examined genes of insects from several orders that feed on milkweed and dogbane plants. Though the insects (butterflies, moths, beetles, true bugs, aphids) are well separated from one another in their taxonomy and evolutionary history, they share the basic genes regulating cellular exchange of sodium and potassium, the proteins for which are affected by the plants’ poisons. A common pattern was gene duplication, with one copy available to mutate into a resistant form that allowed normal exchange of those ions within gut cells. The same gene was involved in all those diverse species, indicating the course of evolution was somewhat predictable.

Here is a gallery of local insects which eat milkweed and dogbane leaves, illustrating the diversity.

Monarch

Large milkweed bug

Red milkweed beetle

Milkweed tussock moth caterpillar

Milkweed leaf beetle

Dogbane beetle

Note how common orange appears among the milkweed insects’ colors. Is there a common genetic factor there as well?

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: