How does the butterfly get its spots?

All we found were sawfly larvae.
This summer, my daughter and I have gone on several “bug-hunting expeditions”. These expeditions always begin with the same elaborate routine: donning the explorer vest, collecting the magnifying glass, bug house and butterfly net, and consulting the “bug map”. The goal is to find a caterpillar that we can capture, feed and watch as it morphs into a butterfly. So far the only thing remotely resembling a caterpillar we have found is sawfly larvae.

My daughter is fascinated by butterflies. We have at least three books on her bookshelf about butterfly life cycles, and just the other week, a trip to the library yielded yet another butterfly book for bedtime reading. Butterflies are fascinating creatures. Not just for the four-year-old who wonders in awe at their amazing life cycle, but for the biologist who marvels at the development of the intricate pattern of their wing eyespots. Wing patterns in butterflies are amazingly varied among species and between different wing surfaces (forewing and hindwing) of the same individual. How are these patterns determined? Continue reading “How does the butterfly get its spots?”

When it Comes to Limb Development, Marsupials Have a Leg Up

PHOTOMICROGRAPH OF MOUSE BLASTOCYST WITH INNER CELL MASS VISIBLE AT 6 O'CLOCK. EMBRYO MOUSE BLASTOCYST INNER CELL MASS

We have probably all seen these creatures somewhere. After all, the image of a pink undeveloped marsupial embryo living outside its mother’s womb is a staple of nature shows and biology films.  The fact that these mammals do the majority of their developing outside of the womb is enough to set them apart, but new research out of Duke University shows that it is more than just where they develop that is different; their timeline of development is different (1). Continue reading “When it Comes to Limb Development, Marsupials Have a Leg Up”