It makes the argument, which I think is widely accepted, that dinosaurs went extinct in essentially one day, or a little longer if some survived the impact and immediate aftermath of the asteroid strike. Maybe it took a year to full extinctify all of them.
So boom. One day you've got a world full of dinosaurs munching on vegetation and each other, and then you go back a year later and you've got a barren wasteland full of corpses. The article says "the available fossil record shows that about 75 percent of known species completely disappeared, and things probably weren’t rosy for the survivors. “It’s is reasonable to suppose that the 25 percent of surviving species had near-total mortality...”. In other words, 75 percent of species were wiped out immediately, and the other 25 percent were almost wiped out.
Now, we generally have something like this happen about every 60 to 150 million years, because there have been five mass extinction events since life began forming on earth. Read more here if you're interested: https://www.nhm.ac.uk/discover/what-...sixth-one.html
For whatever reason, this is the cycle.
We had the first one, then 69 million years later we had the second.
Then we skipped a cycle and had the third one 124 million years after the second.
The fourth one was a bit ahead of schedule, happening 50 million years after the third one.
Then the fifth one (the dinosaur one) skipped a cycle and happened 135 million years after the fourth one.
Don't think about the fact that it's been 65 million years since the last one, by the way. Just put that out of your mind.
So the bottom line is that we get hammered on a cycle of about 65 million years, but sometimes we dodge the problem and get it on the next round at 130 million years.
So my question is, what would have happened if the asteroid that caused the last one 65 million years ago somehow missed us and the dinosaurs didn't get wiped out. Would we still have dinosaurs today? Or would cavemen have hunted them to extinction? Or would they have gone extinct naturally before humans came around, due to climate change or some such thing?
Disclaimer: if you believe the earth is less than 65 million years old, just move along and talk football. This thread has nothing for you. [Reply]
Originally Posted by Rain Man:
Maybe height is no longer an evolutionary advantage, though. As a society, we tend to like tallness for historic reasons, but the skills that come with height aren't very high value today. We don't need someone who can get more leverage on a spear throw.
According to some of the things I read on reddit, many single women will not consider dating any men under 6'-0". My conclusion is that social trends are influencing some women to be as shallow as some men in selecting mates. If this social trend were greatly intensify and to persist for many generations to the point that nearly all humans possessed genes favoring greater height, this would be the first example of gene-culure Co-evolition in humans in 300,000 years. [Reply]
Originally Posted by DJ's left nut:
I have nothing to add in response to the OP.
I did want to remind you, however, that the Tyrannosaurus Rex (extinct 65 million years ago) lived closer in time to humans than it did to the Stegosaurus (extinct 150 million years ago).
We almost can't even wrap our minds around how successful dinosaurs were as a group. To exist in a substantially similar form for nearly 200 million years is really remarkable.
Hey, I already said that! Lol.
Originally Posted by Rain Man:
I find it interesting to think about why we (and other creatures) evolve. I think the classic theory is that evolution increases our odds of procreating and carrying on the genes that are slightly different and superior for survival/procreation.
But how does that work for modern humans when survival is not really a personal issue? There are some attributes that help men procreate now such as a witty demeanor in bars and the ability to earn money. Women are aided by perky breasts and nice figures. But those things aren't necessary as plenty of people without those features can also procreate rather easily. The difference is very very slight if there's indeed a difference at all.
So does that argue that humans have stopped evolving?
I remember reading a statement once that humans may slowly lose our littlest toe in the future because it's not necessary now that we're not climbing trees to escape giant wolves. But I don't see how that's the case. Losing my little toe might make me very slightly faster, but I don't have to be fast to survive. I think little toes are here to stay unless somehow women find four-toed men irresistible and refuse to mate with five-toed men.
I think a big part of evolution is natural selection, which our technology and medicine is starting to phase out in a big way.
Only the worst afflictions will keep a human from making it to puberty and being able to reproduce.
Originally Posted by cdcox:
According to some of the things I read on reddit, many single women will not consider dating any men under 6'-0". My conclusion is that social trends are influencing some women to be as shallow as some men in selecting mates. If this social trend were greatly intensify and to persist for many generations to the point that nearly all humans possessed genes favoring greater height, this would be the first example of gene-culure Co-evolition in humans in 300,000 years.
I think this is a bit overblown and something that’s new to the online dating era.
Not that women didn’t prefer taller men in the past, but it’s so much easier to just swipe left on a guy who is 5’10” because he doesn’t have that nice, clean, coveted 6’ on his bio; whereas, in real life that guy’s smile or charm might have caused the same girl to want to give him a chance.
Not to mention the fact that women are notoriously bad at guessing height/length AND dudes lie about it.
I have no doubt that a lot of women have been led astray thinking their 5’9” boyfriend with a 5” chode was 6’ with an 8 inch hog.
Originally Posted by Fish:
I keenly remember my high school biology teacher talking about evolution. He told us one day that he fears that the human race is slowly evolving ourselves into a corner in a manner of speaking. As in, back in the days of cave man, if Ugg was born with bad eyesight, he was the first of the tribe to be eaten by sabre tooth tigers. Preventing Ugg from passing on his bad eye sight genes. Our technology and medicine is potentially causing us to evolve away from a survival of the fittest model which ensured the betterment of our traits. Now we simply slap a pair of glasses on, and screw over future generations.
The human race might be better off with more man eating predators, to be honest.
I feel like our technology and medicine is making most of this obsolete anyway.
Ideally, we’ll eradicate all but the worst, most aggressive afflictions within the next couple hundred years. [Reply]
Originally Posted by Fish:
I keenly remember my high school biology teacher talking about evolution. He told us one day that he fears that the human race is slowly evolving ourselves into a corner in a manner of speaking. As in, back in the days of cave man, if Ugg was born with bad eyesight, he was the first of the tribe to be eaten by sabre tooth tigers. Preventing Ugg from passing on his bad eye sight genes. Our technology and medicine is potentially causing us to evolve away from a survival of the fittest model which ensured the betterment of our traits. Now we simply slap a pair of glasses on, and screw over future generations.
The human race might be better off with more man eating predators, to be honest.
I've long maintained that is why people start feeling like shit around their 40th birthday.
Our bodies were designed to get eating by a saber cat by the time we're 32. We're built for 20-30 good years and then it's just us toddling about on a bunch of parts that are well outside their warranty period. [Reply]
Originally Posted by -King-:
So how small were the dinosaurs that eventually evolved into birds? And how did they survive? Surely they couldn't have hid out in caves for thousands(?) of years while the planet reset itself and still keep evolving flight ability so how did they survive and keep evolving?
As much as this stuff interests me, I'm pretty stupid when it comes to it, so sorry if it's a dumb question :-)
Originally Posted by DJ's left nut: Our bodies were designed to get eating by a saber cat by the time we're 32. We're built for 20-30 good years and then it's just us toddling about on a bunch of parts that are well outside their warranty period.
Originally Posted by scho63:
So when did Fred Flintstone die?
I remember some line in that show once when Fred was talking about his dad and said "My dad ate meat every day and lived to the ripe old age of 35...."
