Thursday, April 19, 2012

Egg-maculate conception

I've long said that if I was a benevolent deity the first thing I would do was give penguins the ability to produce live offspring at sea, the way whales and otters do.  My opinion has been that all birds lay eggs that need to be kept warm and be exposed to air, and no bird can give live birth, and therefore it would require the intercession of a god to produce a bird that could develop its eggs either internally or under (cold) water.

Well, that may still be true, but consider the following  from the BBC today:

'Eggless' chick laid by hen in Sri Lanka 

Instead of passing out of the hen's body and being incubated outside, the egg was incubated in the hen for 21 days and then hatched inside the hen.
The chick is fully formed and healthy, although the mother has died.
Let's assume for a moment that this is true, and neither a prank nor a misunderstanding. What seems to have happened is that the egg was retained inside the mother's reproductive tract. This (technically called dystocia) happens occasionally, especially to older hens. The egg just gets stuck, and usually eventually breaks and comes out in pieces, which can often kill the mother, and which also smells terrible, as the egg is usually quite rotten. But in this case it appears that the retained egg developed successfully, and the mother wasn't killed until the chick was viable. So assuming this is true, it is the first example of live birth in a bird I can find.

Now before all you penguins trade in your carefully maintained rock scrapes and hole-nests for shrines to the fertility god, keep in mind the following:
1. The mother died, probably quite painfully, and therefore is not around to feed the chick.
2. It would be hard for a trait like that to spread through a population, as each mother could produce only one offspring, and sexually reproducing mothers need to produce at least two adult offspring to reach replacement.
3. It probably isn't true anyway.

Still, it is an interesting story. If a group of birds could for some other reason first evolve to have un-calcified eggs, then it seems more likely that live birth would have a chance of evolving.

Tuesday, April 03, 2012

Accepted, but...

We have set ourselves a difficult task. Some months ago, my friends and I submitted a review article, clarifying some common (within the scientific literature) misconceptions, to a very good anthropology journal. Today we heard back from them. The editor explained that it took longer than usual because he had sent it out to "several" reviewers, and then "several more" and was waiting to get comments from all of them.

The good news is that all the reviewers seemed to like it, and the editor knows which issue of the journal he wants to put it in, which we take as the paper being accepted. The bad news (or at least time-consuming news) is that all of the several and several reviewers made long lists of things they would like to see changed, added, clarified or reorganized. I have not yet finished reading all these comments, but I don't see a lot of repetition, meaning that we have hundreds of distinct comments and criticisms to deal with. In the months we were waiting, we also showed the draft to a couple of colleagues, who gave us still different but also very useful comments. The good news is that the editor has given us permission to go well beyond the usual page limit for this journal in order to deal with all the reviewer comments. The bad news is that we now can't use space limitations as an excuse for not dealing with relevant points or citing relevant literature. So we have a great deal of rewriting to do.

Part of the problem with writing an article pointing out places where other people's thinking or language has been unclear is that one has to live up to very high standards for clarity in one's thinking and language. We've already extensively rewritten this paper a few times, and each time it has gotten clearer. Nevertheless, a large portion of the reviewers' comments are right on, and further clarification is needed. By the time this thing comes out it will either be brilliant or a total muddle. I'm not clear which.