Birds had to relearn flight after meteor wiped out dinosaurs

[cwmma]

This seems to say that forests were gone, so all tree dwelling birds died out and thus all modern birds are descended from ground dwelling birds. Looking at the paper [1] it seems to only say 'reduced flight capacity' which makes more sense, considering we only know of 4 times flight has only evolved so this would be a big deal if birds had evolved it twice.

1. https://www.cell.com/current-biology/fulltext/S0960-9822(18)...

[dekhn]

Basically, you can't take any science reporting major media at face value. The headlines are written as click-bait, and typically in a non-scientific fashion. Some scientists are also prone to releasing catchy PR that misinterprets their results.

[robbrown451]

But this time they wouldn't have to evolve it from scratch. It's not hard to imagine a bird such as an ostrich evolving into a flight capable bird, especially if there were no existing flighted birds to compete with. They have elaborate feathered wings, so the biggest change needed is probably just to be smaller. Probably 99.9% of the DNA necessary for flight is already there, it just needs to be regulated a bit differently. This would even be true in birds like kiwis or emus, whose wings are much smaller and vestigial.

[lomnakkus]

Yes.

I know nothing about the evolutionary origin/path of the chicken except that it's a "flightless dinosaur". It certainly has "reduced flight capacity", but given evolutionary time and pressure, it certainly doesn't seem like a controversial idea that chickens -- given the right selective pressure -- could evolve in a direction towards being fully flighted dinos again...?

[taeric]

To be fair, the headline is not that they reevolved the ability, but that they had to relearn flight. I was expecting it to say more that many of the strategies that were dominate for flight died off. I was guessing dominate air currents higher up, possibly something crazy like a change in dominate gasses.

Point being, same basic birds. Just new advantages steering dominate flight patterns. Not a new mechanism of flight.

(Which, yeah, I guess that is all part and parcel of evolution...)

[GuiA]

It would certainly be a fantastic discovery, but would it be that surprising? The amount of knowledge we can infer from the fossil record is infinitesimal compared to all that actually happened; and while going from 0 instances of an event to 1 is notable (it tells us that “it can happen”), so is 1 to 2 (it tells us that “it can happen more than once”), but is 4 to 5 that crazy?

[subleq]

What are the 4 times that flight has evolved?

[bjd2385]

I liked the article's statement that "there were no more perches." Is that to say, then, that even birds that "perch" refused to do so on cliffs? Certainly, not all of the trees perished as well.

[Isamu]

I never understood the evolutionary push to develop flight, because I thought of it as an expensive form of transport.

Until this graph, which shows the cost of transport to actually favor flight over terrestrial locomotion.

http://www.wprize.org/images/TuckerCostGraph.gif

[xerxes777]

Better quality: https://i.imgur.com/bBJTGyE.png

[yay_cloud2]

Can someone help me understand how to read/interpret this graph? I tried to make sense of it, but I think I was only fooling myself. I need to get planed.

[reubenswartz]

Also very handy for avoiding predators.

[soared]

Any other info or a higher res for that graph? That totally goes against what I would've assumed! (Trains are wildly inefficient?! Swimming is more efficient than flying or running?)

[dluan]

I like to think of flight as an artifact of nice pleasant gusts of wind on this particular planet.

[natch]

I'd like to see where the Voyager spacecraft fits on that.

[ouid]

were you just unaware of how far migratory birds travel?

[deepsun]

What about tons of regular birds that don't need trees? Eagles, condors, gulls, albatrosses, etc.

[vvanders]

Where do you think eagles nest and raise their young before they can learn to fly?

[pfdietz]

Species like those likely wouldn't have survived the food web collapse at the extinction.

[skybrian]

Note that ground-dwelling doesn't necessarily mean flightless. The article in Cell only says they were "non-arboreal" and hardly mentions flight.

[artur_makly]

i must have missed that day in Science class..but when did they prove a massive meteor hit and killed Dino?

[gus_massa]

Nothing is 100% proved, but https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_e...

In particular

> In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows high levels of the metal iridium, which is rare in the Earth's crust, but abundant in asteroids.

[ghaff]

There have been a number of discoveries but the most central one is probably of an Iridium layer by Alvarez in 1980. AFAIK there’s still debate around whether the meteorite that landed in the Gulf of Mexico was truly the Dino killer or if it just hastened a process that was well on its way in any case.

[natch]

Science keeps going after your classes are over.

[Roboprog]

Fred was devastated

[pfdietz]

BTW, it is now thought that all existing species of placental mammals are descended from a SINGLE species that survived the K-Pg boundary extinction.

[Tloewald]

Given the incompleteness of our fossil records, this makes the old joke about the astrophysicist and the black sheep seem apropos.

[riazrizvi]

Nature 0. Nurture +1.