Tweeting, Chattering or Squawking

Tweeting, chattering or squawking is a choice open to some birds. A relatively few can learn to vocalize. Parrots, mina birds and the little zebra finch are examples. To be vocal takes a big frontal brain lobes and in humans this part of the brain matures later than the other parts and it turns out that the same is true for vocal learners amongst the birds.

The question that was keeping Chen et al up nights was this an evolutionary trait that was programmed into the cells, or was this dependent on interaction with the surrounding cell. One way to find out is to mix and match and this was the experiment. They, used zebra finch and Japanese quail eggs, an array of sharp knives and syringes and manufactured some finch/quail chimeras (1).

The part of the brain that develops into the frontal lobes is known as the telencephalon and it was this part of the early finch embryos that was used to replace that of the quails. Then one has to wait.

In the fullness of time the chimeric brains were developing well and these brains were examined along with brains of normal donors and hosts. Although the species diverged as long ago as 65M years the chimeras were working in the egg, but didn’t hatch.

In the chimera, the telencephala grew larger than in finches, but was smaller than quails. The conclusion of the study was that cell autonomous (evolutionary control) and cell-interdependence were both involved.

With a zero hatch rate, it looks like we won’t hear quail protesting coherently when they are being picked out for the pot at your next dinner party.

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