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Scientists Say The Asteroid That Killed The Dinosaurs Almost Wiped Us Out Too (theweek.com)
HughPickens.com writes: Conventional wisdom states that mammalian diversity emerged from the ashes of the Cretaceous/Tertiary mass extinction event, ultimately giving rise to our own humble species. But Joshua A. Krisch writes at This Week that the asteroid that decimated the dinosaurs also wiped out roughly 93 percent of all mammalian species. "Because mammals did so well after the extinction, we have tended to assume that it didn't hit them as hard," says Nick Longrich. "However our analysis shows that the mammals were hit harder than most groups of animals, such as lizards, turtles, crocodilians, but they proved to be far more adaptable in the aftermath." Mammals survived, multiplied, and ultimately gave rise to human beings.
So what was the great secret that our possum-like ancestors knew that dinosaurs did not? One answer is that early mammals were small enough to survive on insects and dying plants, while large dinosaurs and reptiles required a vast diet of leafy greens and healthy prey that simply weren't available in the lean years, post-impact. So brontosauruses starved to death while prehistoric possums filled their far smaller and less discerning bellies. "Even if large herbivorous dinosaurs had managed to survive the initial meteor strike, they would have had nothing to eat," says Russ Graham, "because most of the earth's above-ground plant material had been destroyed." Other studies have suggested that mammals survived by burrowing underground or living near the water, where they would have been somewhat shielded from the intense heatwaves, post-impact. Studies also suggest that mammals may have been better spread-out around the globe, and so had the freedom to recover independently and evolve with greater diversity. "After this extinction event, there was an explosion of diversity, and it was driven by having different evolutionary experiments going on simultaneously in different locations," Longrich says. "This may have helped drive the recovery. With so many different species evolving in different directions in different parts of the world, evolution was more likely to stumble across new evolutionary paths."
That is totally not how things went down.
We got off the ark?
I always imagined that dinosaurs, as part of an ecosystem, were fairly well adapted to their environment. After the "extinction event", which significantly changed the environment and lead to their extinction would also result in the elimination of many species (both flora and fauna).
What I found interesting that is hinted at in the TFA (and had not thought about) was the creation/availability of niches for surviving species to take over and evolve into.
I would be quite interested in finding out if there are any fossil remains of mammals and how they fit into the ecosystem with dinosaurs before the big one hit. Other than cockroaches, I suspect that the Earth's inhabitants were wildly different and the different creatures inhabited different parts of the food chain would be very different from the ones that inhabited it after the meteor strike.
Hopefully this research will result in more study being taken in the world of 60+ million years ago.
Mimetics Inc. Twitter
Decimated means to kill 1 in 10.
The author is not a very good writer. I believe the word he was looking for is annihilated.
This is science. What words mean is important.
According to the Oxford English dictionary, decimate meaning to kill 1/10 is something of an urban legend. You can read it for yourself here.
http://blog.oxforddictionaries...
"Liberalism is a very noble idea, currently controlled by some very bad people. Be sure you do not get the two confused.
Just before the Permian-Triassic extinction event (PT), about 250m years ago, large mammal-like reptiles (proto-mammals) were more common than lizard-like reptiles. The proto-mammals were the top of the food-chain.
But after PT, the lizard-like reptiles recovered faster, becoming the dinosaurs, and the proto-mammals were mostly small skittish creatures.
The Cretaceous-Paleogene extinction event* (CP), the one that ended the dino's about 65m years ago, was pretty much the reverse: the lizard-ish reptiles recovered slower than the mammals.
There was a short period early in the CP recovery where large dinosaur-like birds, think ostrich on steroids, seemed to have had the upper hand. (Birds are closely related to the dino's.) But, mammals eventually prevailed, as least as the largest beasts.
If Trump gets us nuked, large dino/birds/lizards may make a comeback. If the pattern continues, it's their turn again.
* Also known as Cretaceous-Tertiary extinction event
Table-ized A.I.
And not all dinosaur species died out. The avian dinosaurs survived. So we have most mammal lines dying out, and most dinosaur lines dying out. In short: "giant meteor killed most, but not all, species on Earth"
Did he just go crazy and fall asleep?
European animals were decimated, american ones were inchimated.
I turn 40 on my next birthday
No doubt you're a 40 year old virgin.
And not all dinosaur species died out. The avian dinosaurs survived. So we have most mammal lines dying out, and most dinosaur lines dying out. In short: "giant meteor killed most, but not all, species on Earth"
Avian dinosaurs and mammals have several things in common. They both have some form of covering (fur/feathers), they both have a lot of smaller species, they both have a lot of omnivorous species, and most importantly all mammals and many avian species can regulate their own internal body heat. My guess is that the fur/feathers combined with being warm blooded is what gave mammals/avians the biggest lead. With wildly fluctuating temperatures, being able to self-regulate would be a major advantage. I don't think the immediate heat is the problem. The problem is that if you survive that then the dust has now blocked out the sun and temperatures drop for the next several years. Dinosaurs had evolved for a tropical environment and would have had no way to deal with several years of cold weather. This also explains why most of the reptiles that did survive are aquatic. Water would have helped the aquatic species regulate their body temperatures better.
So was the asteroid really that bad? Honestly, I just don't care anymore. What I do care about is the pseudoscience passed off as facts as if the scientific community is doing more than trying to tell a consistent story based on a minuscule amount of evidence. The sad thing is scientists can't agree on theories when there is a preponderance of evidence. What hope do we have of knowing something that happened to living things millions of years ago. Quit sensationalizing this stuff.
Sounds like you need religion, not science.
I think you crave consistency, and unchanging thought, which religion by it's nature provides.
Regardless, the idea that dinosaurs were on the decline is not contradicting of a meteor strike. It might have been the event that ended dinosaurs as the alpha critters on the planet, but in fact it didn't even completely wipe out the dinosaurs, they are still among us as birds.
This idea that mammals were largely decimated is perfectly consistent with a large asteroid strike as well.
And rather than getting distressed as the pieces of the puzzle are filled in, some of us get in a more celebratory mood as we gain more evidence. The various fields with their individual facts correlating with other disciplines, with geology, physics, paleontology, and often others converging on a likely scenario, and then further research showing the plausibility or lack of plausibility are just plain exciting. Even when wrong, it teaches us which way we don't want to look in the future.
What causes you distress, causes many of us excitement. But it is knowledge versus being certain of something
Which is why I suggest the surety of religion for you, especially of the fundamentalist kind.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
And not all dinosaur species died out. The avian dinosaurs survived. So we have most mammal lines dying out, and most dinosaur lines dying out. In short: "giant meteor killed most, but not all, species on Earth"
Exactly. Now the hypothesis that small mammals, reptiles, amphibians, and the avian critters survived on dead plants and seeds is very plausible. it's going to be difficult to prove that exactly, but it doesn't take anything magical for the predisposed and lucky to survive on what they might have eaten anyway, while the earth regenerated from the same seeds. I see the squirrels, chipmunks and birds doing that in the backyard every day, and anyone seeing a gorgeous pileated woodpecker will get the bird/dinosaur connection immediately.
Which brings to mind the paleontological issue I'm more interested in lately - that many dinosaurs were feathered. I'm fascinated by the possibility that rather than ugly leatherbags, that dinosurs might hve been colorful feathered megabirds in appearance.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
Indeed. Think of the massive amount of organic matter in the Cretaceous hothouse environment before the K-Pg impact. Even with all of the wildfires, there would have been a truly massive amount of it left. And thus detrivores and decomposers. And thus things who eat those things, and things who eat those. There was no shortage of food overall - just a radically, radically altered environment, with vastly reduced populations. I actually find it more amazing that plants made it than that animals did.
Speaking of birds/dinosaurs... it's not just only about appearances - picture their behaviors too. For example, parrots often have something called "eye pinning" in their threat displays. In rapid, jerky movements they lean their head down, back up, tail flayed out like a fan showing their bright colors, and stare down their targets. Their pupils pulsate in size - big, small, big, small, every 1-3 seconds. A beating black circle in an angry orange eye. Now picture that sort of threat display on something as big as, say, a T-rex. Can you think of anything more terrifying than that? Meanwhile a parrot may switch between holding perfectly still, and suddenly randomly snapping at anything, literally anything in range - clamping down on a stick, a toy, a steel bar, whatever, as hard as it possibly can, while staring at you with its pulsing eyes, as if to say, "THIS IS GONNA BE YOU NEXT!". Now again, imagine something the size of a T-rex, doing that display, snapping at whole tree trunks while pulsing its eyes at you.
Birds are also famous for having complex, diverse calls. The reason for this is that they have a syrinx rather than a larynx for making vocalizations. It's based around vibrating the walls rather than cords; the walls are divided and varied in tension, so they can impart multiple tones at the same time. Many of their ancestors probably had similar abilities. So expect complex "dinosaur song", or at least theropod song.
Did he just go crazy and fall asleep?
Religion, at its foundation, is about the experience of humanity. And, in as much as humans are the same as they always have been, the lessons of religions are immutably valid.
Religions even speak narratives today, fraught with meaning concerning large groups of people. I hope the lessons learned from the growth of religions to their current proportions can find their way into our lexicons of knowledge for future generations, much as religious texts did for early mankind. That said, our chroniclers are no longer the shaman and elders they once were, and their analogous oral histories and manuscripts have been replaced by peer reviewed papers and investigative journalism.
For the well read it is easy to see how the shift from inherited wisdom to procedural knowledge has also resulted in a shift from broad strokes to incredibly detailed minutiae. I long for an updated text, encompassing truth for the ages, designed to be passed to future generations, but developed by a modern mindset and devoid of the pitfalls of some of the current religions. Were I to have the honor I would call it "A handbook for those that walk with humans."
When the only tool you have is a claw hammer every problem starts to look like the back of someone's skull.
Well, at least the theropods are birdlike. The further you get toward the stegosaurus end of the dinosaur spectrum the closer you'll get to crocodilians (crocodilians are not descendants of dinosaurs but they're very close; their common ancestor isn't even as far back as the common ancestor between dinosaurs and pterosaurs.
The amazing thing to me is it's starting to look more and more like, in the right conditions, you can actually recover soft tissue from dinosaurs, even sequence proteins. There was some skepticism early on (arguing contamination and the like), but today the consensus seems to be they actually are what they appear to be: actual dinosaur soft tissue.
Previously, our best bet for "recreating dinosaurs" has been:
1) to start by contrasting bird genomes with other branches close to dinosaurs, like crocodilians, to reverse engineer as much of a generic "dinosaur genome" as possible (getting rid of as many of the avian changes that occurred in the past 65M+ years as we can)
2) For the rest, as much as you can, activate / deactivate genes that are already present in living species that are responsible for desired morphological features that may well have been active/inactive in the past
3) Where otherwise necessary, use custom insertions/ modification to recreate morphological features that we no longer have a trace of.
It's something... but not perfect. A great deal would be guesswork, at least when you only have modern species and fossilized bone structure to go on. But when you start having a wide variety of soft tissues that you can study on both macroscopic and microscopic scales, suddenly that's a very different picture. You know how the cells should look. You can see how each of the organs should be developing. You know what proteins are being produced - at least the bulk ones. It might actually be possible to get quite close to actual dinosaurs, even non-theropod dinosaurs whose specific mutations have been totally lost.
Did he just go crazy and fall asleep?