However, I can easily say that it appears to the best developed for sheer survival.

Honestly, those things jump out at you at the most unexpected times…

The brilliant thing is that that would cause me to need to visit South America, where I could potentially add hundreds of species to my list.

Excuse the rabid ticker now. ;)

There are so many people in the world that leaving the ornitothologists to doing what they want to do isn’t hurting anything. The little things are important too, and focusing everyone on one single problem doesn’t get it done any faster. People who are good at solving the big problems will solve them, the others will solve a little problem that may turn out to be a big thing – some of the smallest problems in history have produced some of the best inventions.

Yes! And I hear that many other people are actually doing insignificant things like brushing their teeth and showering instead of working on more important problems, like world peace! ;-P

There are plenty of people in the world, I don’t see a problem with a few of them spending some of their time solving questions like these.

science-writer said: “Presumably, some kind of comparative DNA analysis would allow its lineage to be worked out quite quickly, I just don’t fancy being the grad student who has to collect the sample if this thing smells like you say.”

Well, according to the Wikipedia article linked to above, the recent comparative DNA analyses put it most likely in a new category, Metaves, along with doves, flamingos, and a few other species of birds.

No need, you’ve already done all of the twisting.

Evolution doesn’t “want” anything, it is a blind process where traits that improve survival and breeding success tend to be passed on and increase in a population. Evolution does not have a “goal” to make things live forever either.

The simple problem with evolving “immortality” is that traits which affect an individual after it has finished breeding (and rearing young in species that do that) are not very relevant from an evolutionary perspective. For example, presbyopia is a hardening of the lens in the eye that occurs as you get older, usually after child bearing age in humans. Evolution has almost no way to select against a trait that only appears after the genes have already been passed on to the next generation. It’s simply too late to select against those genes. The cat, as they say, is already out of the bag. This goes for most of the genes that control an organism’s life after childbirth and any rearing of young is complete. Furthermore, evolution may even select for those harmful traits if they help the next generation survive.

Keep in mind that once a creature has bred (and possibly raised its young) if it stayed around it would probably end up in competition with with its young for resources and such. Depending on the number and survival rate of the young that will determine how many breeding cycles are optimal. After that point, the young are more likely to survive if the parent dies off.

Of course, if a parent has a trait that helps its young survive, and that trait is also in the young, then that trait can be selected for in evolution. This means that since the young bear the same genes as the parents, any gene that causes the parents to die off at an optimal time to open up more resources for the young will tend to exist in the young as well. Since those “dying off”-type genes benefit the young they will tend to get passed on.

In addition to all of that, you have to remember that evolution is a juggling act, and there are many forces at play. If a species reproduces too much without earlier generations dying off quickly enough they can end up consuming all of the resources and create a famine for their species. On the other hand, if you have a long-lived population that breeds fairly slowly (usually at a later age) so as not to strip themselves of resources, one disaster could reduce the population to the point where it could not reproduce enough to recover in time. If the population does not quickly return to its previous size (which it couldn’t do if it was a slow-breeding population) then other species will usually take over those resources, and make the maximum sustainable size of the slow-breeding species smaller than it was before. Repeat incidents like that enough times, and the population will become too small to sustain itself, and die off.

All of that means that species that are too long lived with a high breeding rate can starve themselves out, or if they have a slower breeding rate that is optimal for their lifespans, a periodic disaster will favor shorter-lived faster-breeding species instead of a longer-lived slower-breeding species.

If you want the simple version, imagine what the world would be like if nothing died of old age.

In short, all of that means that longevity beyond a certain point is not a helpful survival trait for a species. That’s a large portion of why evolution doesn’t produce “immortal” species.

Just because we generally see dying of old age as a bad thing, does not mean that it’s not a good thing from an evolutionary perspective.

Troll ftw