What an Extinct Bird Re-Evolving Says About “Species”

Convergent evolution is fascinating.

Environments produce animals in some way and a similar environment will cause similar animals to evolve again given time.

New Zealand's kiwi is a bird version of a mouse because mice weren't around to fill that niche.

There are many examples that are bafflingly similar yet share very distant common ancestors:

https://en.m.wikipedia.org/wiki/List_of_examples_of_converge...

Makes you wonder if the sci fi with human looking aliens is not so far off.

The difficulty of defining a ‘species’ reminds me of one of my favorite essays about how we categorize things.

https://www.lesswrong.com/posts/aMHq4mA2PHSM2TMoH/the-catego...

Just wait until the start re-evolving back into dinosaur form, then you are really going to be in trouble :-). I believe there is probably a good fictional short story involving a scheme to remove CO2 from the air to fight climate change, having it go amok and instead result in a second "oxygenation event"[1] making very large animals practical again from an energy conversion standpoint.

[1] https://simple.wikipedia.org/wiki/Great_Oxygenation_Event

> This raises an interesting question: Can birds on different branches of the evolutionary tree really be part of the same species? The answer depends on what you mean by “species.” This is the species problem, one of philosophy of biology’s persistent demons. As it turns out, it is difficult (and some would argue, impossible) to conceptualize species in a way that fully, and without exception, captures what it is that makes a group of organisms one species and not another.

I’ve always found clicking through species pages on Wikipedia to see the variations of different animals and the often surprising ways they are interconnected.

It seems like an incredibly hard thing to get right as the categorization constantly changes as more and more DNA analysis disrupts the old lines.

I’d be interested in reading the history of this labelling system and how it evolved. There might be some connection to software and language itself.