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Humans' Big Brains Linked To a Small Stretch of DNA
A new study (abstract) described in the L.A. Times suggests that "just 10 differences on one particular strand of human DNA lying near a brain-development gene could have been instrumental in the explosive growth in the human neocortex."
The DNA region, containing just 1,200 base pairs, is not a gene. But it lies near one that is known to affect early development of the human neocortex, according to the study, published online Thursday in Current Biology. Researchers showed that the region, known as HARE5, acts as an enhancer of the gene FZD8. Embryos of mice altered with human HARE5 developed significantly larger brains and more neurons compared with embryos carrying the chimp version, according to the study.
Facebook , whatsapp .. HARE5 is certainly mutating .. some of the recent human DNA will make mice with smaller heads .. The world is going to be dumb eventually ..The dumb people make more babies .. The smart ones are still workin on that thesis they have to finish.
next time on Pinky & the Brain...
If we learned anything from The Hitchhiker's Guide, it is that the mice are the supreme species on earth.
http://en.wikipedia.org/wiki/L...
What's the point of injecting inferior genes into their brains?
On a more serious note, it will probably be a long time before genetic science can safely determine the source of intelligence or any way to manipulate it. And a long time beyond that to overcome social and legal impediments to using the knowledge in any practical way. Expect to be just as dumb as you are for the rest of your life.
...omphaloskepsis often...
Other species have what we donot . A tiger can decapitate a human with a single strike of the claw ( ~= 300kg force) , a shark can smell a drop of blood from 10 kms away ( ~= 60% of the brain dedicated to olfactory processing) .. Thats where their evolutionary "currency" was spent . It's like while they were building a supermassive electronic typewriter, we invented the computer.
Then why doesn't someone make these 10 changes to a chimp egg and sperm and see what happens?
Thats where their evolutionary "currency" was spent
The currency is the food needed to grow the tissue and support it. Evolution itself doesn't cost anything.
But if it was evolution alone, other species would have it too
You assume that bigger brains offer a net benefit to other species. The problem is that large brains consume a large amount of energy. If the extra intelligence doesn't help to acquire extra food, the bigger brain is not a asset. Also, acquiring food is only part of the equation. Animals must also be able to actually eat and digest it. An animal like a cow already spends every waking moment on eating and digesting. Even if bigger brain could help it find more grass, there's still not enough time to actually process enough of it.
Apparently, this enlargement is not sufficient to prevent dup in /.
Video of some good progressive thrash music
Intelligence can do far more than gather food more effectively. Less intelligent critters are plenty good at that as well. Early proto-humans probably had some other advantages, such as the ability to adapt to changing conditions, or to create tools useful for weapons or defense, all thanks to bigger brains. Intelligence is really the ultimate utility trait, because it allows for better adaptation that might cause other animals to simply die out. Look at how successfully early humans survived all over the globe, in almost every climate, even without dramatic physical alterations - only minor differences, such as eye shape, skin pigmentation, etc.
That being said, the other advantage we have is the evolutionary path that allowed us better use of those big brains, such as the ability to walk upright and opposable thumbs on very dexterous hands. As such, we can more easily shape the world to our advantage through sophisticated tools. Without the proper bodies to manipulate the world around them, intelligence would do a creature far less good. Improved intelligence may have been tried before, but it may not have been worth the increased nutritional demands without the correct body to take advantage of it.
Irony: Agile development has too much intertia to be abandoned now.
Don't feed the trolls. Especially the cray-cray trolls.
I've fallen off your lawn, and I can't get up.
Algernon? Is that you?
I've fallen off your lawn, and I can't get up.
What does this mean for lesser human beings, in a world where animals are slaughtered without so much as a care to allow them to turn around in gestation crates.
Well we already have zoos, chicken farms, etc. No reason a few humans wouldn't fit in there. ;-)
Intelligence can do far more than gather food more effectively. Less intelligent critters are plenty good at that as well
The point is that they need to "pay" for their bigger brain by eating more food. And for a creature with a small body, it means a a lot more food. So, it doesn't matter what nice things intelligence can do for a creature, if it can't afford the energy for it.
So they're breeding mice with the genes of a human brain? As Kramer said in that episode, there is a secret plan for pig men, or rather rat men.
Well, yeah, I'm not really disagreeing with you regarding that. I'm aware that it's an extremely expensive organ in terms of nutrient consumption. I was just pointing out that intelligence offers more benefits than increased food gathering capabilities.
Interestingly, you talk about the need eat a lot of food. Our human brain actually allows us a richer diet by giving us the intelligence to cook our food. That makes it easier for us to digest meat, which in turn makes us more efficient predators. I've read that some researches believe cooking our food enabled us to eventually evolve smaller guts, which allowed that extra nutrition to go towards enhancing our brains instead.
Food for thought, one might say?
Irony: Agile development has too much intertia to be abandoned now.
Still, many things can happen in parallel. A tiger could have evolved to have bigger muscles, and a bigger brain at the same time.
Yes, there's a theory that humans cooking their food was a big enabler for their bigger brains, because the cooking process makes it a lot easier to digest the food and absorb more of the nutrients in a short time. But the ability to cook the food depends on a lot more than being intelligent. You also need the body that allows manipulation of tools so you can carry the fire wood, start a fire and control it, and carry the food to the fire. That's something that our bipedal humanoid ancestors could do well, but most other animals would not be able to pull off, even if they were a little bit smarter.
Aye,
Some dogs can understand over 200 words. And dolphin which are predatory creatures are very intelligent and are close to the weight of tigers (200kg vs 225kg for largest).
The long term bacterial experiment also shows that many mutations occur constantly which have no immediate effect. As long as they are not detrimental, they get carried along. For example- humans average 67 mutations compared to their parents.
Combinations of these benign "noise" mutations separated by thousands of generations in the bacteria resulted in dramatic abilities (such as the ability to consume previously inedible substances).
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
Maybe, but I bet it doesn't know what a newton is.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
But if it was evolution alone, other species would have it too.
Evolutionary innovations don't work like that. There's a species that's first. It might not keep the monopoly for long, but humans haven't been around for long.
It should also be considered that for many animals, a gradual increase in intelligence and brain mass isn't much of an advantage. What would a smart cow do differently? Would a mouse be able to use tools even if it knew how to make them? Even apes smart enough to use many tools can't do so effectively because they simply lack the fine motor skills to execute. I would argue that it was not until our ancestors were 1) standing with two very dexterous spare limbs to play with, and 2) out of our natural environment where there isn't food a-plenty, that even small increases in intelligence was a big advantage. We needed to hunt (communicate and coordinate), and we had the dexterity and capability to carry items over distance that made intelligence worthwhile.
It should also be considered that for many animals, a gradual increase in intelligence and brain mass isn't much of an advantage. What would a smart cow do differently? I would argue that it was not until our ancestors were 1) standing with two very dexterous spare limbs to play with, and 2) out of our natural environment where there isn't food a-plenty, that even small increases in intelligence was a big advantage. We needed to hunt (communicate and coordinate), and we had the dexterity and capability to carry items over distance that made intelligence worthwhile.
Look at how successfully early humans survived all over the globe, in almost every climate
Yes along side thousands of other species that are even more widely dispersed and which have been at the game of survival thousands (in some cases billions) of times longer. Come talk to me after humans has surpassed the average mammalian species lifespan (although, at that point the dodo will still have them beat).
Troll is not a replacement for I disagree.
An animal like a cow already spends every waking moment on eating and digesting.
And farting. So many farts.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
Well, yeah, I'm not really disagreeing with you regarding that. I'm aware that it's an extremely expensive organ in terms of nutrient consumption. I was just pointing out that intelligence offers more benefits than increased food gathering capabilities.
It's one metric. But it seems like a "humans are the apex of creation" outlook after a while.
Our intelligence is pretty impressive, but it is just one metric. Some species achieve remarkable success via massive overproduction, some through aggression (more on that) some through specialization.
And is success measured by weight, aplha predation, or intelligence? THere are even honorable mentions for highly adapted senses.
Humans have the intelligence, and the ability to do somkething about it, with our manipulative hands.
But we also have some aggressive traits that might end up placing us right on top of the unsuccessful species list. Much of our ability is tuned to killing each other.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
What would a smart cow do differently?
Not double-post? :-)
Animals are better at communicating when it comes to predator/prey than humans are. They can detect us further away, and flee en masse, same as birds flocking. Or if you're a herd of elephants, just form a circle with heads out and say the equivalent of "do you really want a piece of this"? For most of our human's existence, we were scavengers, same as the vulture and the hyena, because we couldn't compete.
Any group of humans that got too large to be sustained in it's area would end up attacking each other. If the group was too large, the energy spent continuously going to new foraging grounds would be more than the return, so again, they would turn on each other. Yes, I mean Donner Party style. We still see indications of this today, because humans are more aggressive towards each other than towards other animals. It's a survival trait, because the existence of too many humans in one group until recently always meant starvation.
"Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
Currency is a pretty appropriate word to use since a mutation which produces an adaptation which might be useful in that it permits success in a new niche might decrease success in the present one. Time to go...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Being able to put on other animals' skins and dance around is probably a big part of it. Getting fire figured out will have been a trial-and-error-prone process.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The extra calories we consume due to our crappy western diets will be consumed by the larger brain instead of making us obese. Win-Win.
What the hell? Cats make their own vitamin C. Explain that!
In some variants of I.D. genetics, a mutation can only subtract functionality, not add. So some I.D. advocates would claim that humans were created perfect, with the ability to synthesize ascorbic acid, before such a deleterious mutation became fixed in the population during a massive bottleneck in the 24th century BCE. So if Noah Lamechsson had a defective allele for the vitamin C gene, all of humanity ended up with this defect. Other I.D. advocates would counter this with a claim that humans were designed to produce it from DHA.
Personally, I'm more in the "God used evolution as a tool" camp.
You also need the body that allows manipulation of tools so you can carry the fire wood, start a fire and control it, and carry the food to the fire. That's something that our bipedal humanoid ancestors could do well, but most other animals would not be able to pull off
Even without opposable thumbs, tools can stil be figured out. Watch this man chop wood without hands.
I don't believe I declared that humans are the "apex of creation", nor even declared them to the most successful, depending on how you define that. I was just pointing out some advantages of our physiology that's led to our current evolutionary success - meaning we've survived so far as a species. Of course, past success does not guarantee future performance.
By other metrics, such as evolutionary diversity, I might choose ants or arachnids. Maybe simple shrimp species that haven't changed much in 200 million years for longevity. For evolved senses and specialty equipment, perhaps sharks (some of whom are also amazingly old too).
Incidentally, the fact that we kill each other is hardly unique to humans, and doesn't seem a detriment to survival. Ants, spiders, and sharks all kill each other as well. The only thing that makes it dangerous as a species is our most advanced weapons. Even then, it's actually debatable whether we could actually exterminate ourselves via nuclear weapons in a worst case scenario. Recent studies suggest that the effects of nuclear winter, while obviously catastrophic to civilization and mass populations, would not actually end all human life.
Irony: Agile development has too much intertia to be abandoned now.
Intelligence is a plus if the species is opportunistic and social. Like for instance raptors. Standing on rear legs opens opportunities - indicating that it increases chances for opportunistic strategies to outweigh the extra braincost.