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We're lucky to be living in amazing times where the largest creatures that have ever lived on this planet are alive...and their explosion is size is just 3 mill

We're lucky to be living in amazing times where the largest creatures that have ever lived on this planet are alive...and their explosion is size is just 3 million years old.

lokedhs 9y ago
That makes me wonder: What was the largest animal that had ever lived 3 million years ago?
- jacobolus 9y ago
  The largest known sauropods were almost 100 tons and 40 meters long, ~100 million years ago. e.g. https://en.wikipedia.org/wiki/Argentinosaurus https://en.wikipedia.org/wiki/Argentinosaurus For comparison the largest blue whales are up to ~180 tons and 30 meters long, and the largest elephants are ~12 tons and 6 meters long (some prehistoric elephants may have gotten up to 22 tons).
- pvaldes 9y ago
  Probably not. Some marine invertebrates are much longer and being colonial a coral born from a single egg has unlimited growth, so could be theoretically larger than a whale and more massive.
interfixus 9y ago
Which must obviously raise the question: Is the coincidence a coincidence? Which it might well be, but how infinitely more exciting if the giants and we were somehow molded from the same set of circumstances. I am not really qualified to judge whether the article implies such a thing.
- nck4222 9y ago
  The article does not imply such a thing. It might be related, it might not be, but there's been no studies about that, and the paper referenced in the article was published this week.
- Yizahi 9y ago
  I imagine we would have a giant fin along our spine and would be required to sleep in the sun for 10 hours per day and 8 hours per night to be able to function in the rest 6 hours. But on the other hand we would be much smarter with bigger brain in those 6 hours.
dredmorbius 9y ago
All macroscopic life on Earth has existed for only about 600 million years, since the Cambrian Explosion. Significant land life, about 350 million years. Over 4.5 billion years, less than 15% of the total duration of the planet. For most of Earth's existance, if you'd come searching for signs of life, you'd have found little but slime and bacterial stew in oceans and ponds. If that.
nkrisc 9y ago
But much of history was probably the time that the largest animals that ever lived until then were alive.
- LeifCarrotson 9y ago
  Very true. The article adds: > Another hypothesis known as the Brownian motion model of evolution posits that animals get big and small at random. In this scenario, the descendants of an animal would be both larger and smaller than their ancestor, but this didn’t fit with the data either, since whales got only bigger. The hypothesis only applies to large numbers of species. Of course the largest animals only got larger; otherwise they wouldn't be the largest. If every species only got larger, then the model would be false, but some species get larger and some get smaller. In this case, the article does posits an interesting climactic and fossil-record history of a recent growth spurt that's not purely random Brownian motion. But in general, you cannot look at an outlier and infer whether a general rule is true or false.
  - debacle 9y ago
    Animals do tend to get big and smaller at random. Whales appear to have been selected to be bigger. Why is always an interesting question when it comes to evolution. The answer is of course giant undiscovered subaquatic predators.

We're lucky to be living in amazing times where the largest creatures that have ever lived on this planet are alive...and their explosion is size is just 3 million years old.

lokedhs 9y ago

That makes me wonder: What was the largest animal that had ever lived 3 million years ago?

jacobolus 9y ago
The largest known sauropods were almost 100 tons and 40 meters long, ~100 million years ago. e.g. https://en.wikipedia.org/wiki/Argentinosaurus https://en.wikipedia.org/wiki/Argentinosaurus For comparison the largest blue whales are up to ~180 tons and 30 meters long, and the largest elephants are ~12 tons and 6 meters long (some prehistoric elephants may have gotten up to 22 tons).
pvaldes 9y ago
Probably not. Some marine invertebrates are much longer and being colonial a coral born from a single egg has unlimited growth, so could be theoretically larger than a whale and more massive.

interfixus 9y ago

Which must obviously raise the question: Is the coincidence a coincidence? Which it might well be, but how infinitely more exciting if the giants and we were somehow molded from the same set of circumstances. I am not really qualified to judge whether the article implies such a thing.

nck4222 9y ago
The article does not imply such a thing. It might be related, it might not be, but there's been no studies about that, and the paper referenced in the article was published this week.
Yizahi 9y ago
I imagine we would have a giant fin along our spine and would be required to sleep in the sun for 10 hours per day and 8 hours per night to be able to function in the rest 6 hours. But on the other hand we would be much smarter with bigger brain in those 6 hours.

dredmorbius 9y ago

All macroscopic life on Earth has existed for only about 600 million years, since the Cambrian Explosion. Significant land life, about 350 million years. Over 4.5 billion years, less than 15% of the total duration of the planet. For most of Earth's existance, if you'd come searching for signs of life, you'd have found little but slime and bacterial stew in oceans and ponds. If that.

nkrisc 9y ago

But much of history was probably the time that the largest animals that ever lived until then were alive.

LeifCarrotson 9y ago
Very true. The article adds: > Another hypothesis known as the Brownian motion model of evolution posits that animals get big and small at random. In this scenario, the descendants of an animal would be both larger and smaller than their ancestor, but this didn’t fit with the data either, since whales got only bigger. The hypothesis only applies to large numbers of species. Of course the largest animals only got larger; otherwise they wouldn't be the largest. If every species only got larger, then the model would be false, but some species get larger and some get smaller. In this case, the article does posits an interesting climactic and fossil-record history of a recent growth spurt that's not purely random Brownian motion. But in general, you cannot look at an outlier and infer whether a general rule is true or false.
- debacle 9y ago
  Animals do tend to get big and smaller at random. Whales appear to have been selected to be bigger. Why is always an interesting question when it comes to evolution. The answer is of course giant undiscovered subaquatic predators.