MBP - White-throated Sparrows and Supergenes

We're going to learn a lot about supergenes in the coming years. One of the best examples we know of can be observed in any Maryland backyard - the common migrant and wintering species, the White-throated Sparrow. Today's graphic summarizes the differences between "white-striped" and "tan-striped" White-throated Sparrows. White-striped individuals tend to be more aggressive, better singers, and worse parents. Tan-striped individuals tend to be more protective, worse singers, and better parents. White-striped individuals nearly always pair up with tan-striped individuals and vice versa. It's easy to speculate about the advantages of ensuring that mix of strategies, strengths, weaknesses, and genetic variation. Absolutely fascinating and full of implications. Is there an ancient and deeper truth to "opposites attract"? Have you ever noticed how commonly Homo sapiens "introverts" and "extroverts" - these are over-simplified terms, but useful shorthand - pair up?

What else? It's looking like Common Redpoll and Hoary Redpoll are genetically one species with traits that express themselves differently at different latitudes (including climate and habitat).
And those amazing bird examples are eclipsed by the incredible gene expression in the Eurasian shorebird species (and rare but regular North American visitor), the Ruff.

Alvaro Jaramillo did a fantastic job introducing this topic on a recent episode of Life List: A Birding Podcast. I highly recommend listening to that one and subscribing to that podcast if you don't already!
Expression of supergenes:

https://podcasts.apple.com/us/podcast/expression-of-supergenes-in-birds/id1578168978?i=1000648757820

Bill

Posted on March 26, 2024 01:08 AM by billhubick