Posted on 12/29/2004 9:14:28 AM PST by aculeus
Emergence of society may have spurred growth
The sophistication of the human brain is not simply the result of steady evolution, according to new research. Instead, humans are truly privileged animals with brains that have developed in a type of extraordinarily fast evolution that is unique to the species.
"Simply put, evolution has been working very hard to produce us humans," said Bruce Lahn, an assistant professor of human genetics at the University of Chicago and an investigator at the Howard Hughes Medical Institute.
"Our study offers the first genetic evidence that humans occupy a unique position in the tree of life."
Professor Lahn's research, published this week in the journal Cell, suggests that humans evolved their cognitive abilities not owing to a few sporadic and accidental genetic mutations - as is the usual way with traits in living things - but rather from an enormous number of mutations in a short period of time, acquired though an intense selection process favouring complex cognitive abilities.
Evolutionary biologists generally argue that humans have evolved in much the same way as all other life on Earth. Mutations in genes from one generation to the next sometimes give rise to new adaptations to a creature's environment.
Those best adapted to their environment are more likely to survive and pass on their genes to the next generation.
The evolution of a large brain in humans, then, can be seen as similar to the process that leads to longer tusks or bigger antlers. In general terms, and after scaling for body size, brains get bigger and more complex as animals get bigger.
But with humans, the relative size of the brain does not fit the trend - our brains are disproportionately big, much bigger even than the brains of other non-human primates, including our closest relatives, chimpanzees.
Prof Lahn's team examined the DNA of 214 genes involved in brain development in humans, macaques, rats and mice.
By comparing mutations that had no effect on the function of the genes with those mutations that did, they came up with a measure of the pressure of natural selection on those genes.
The scientists found that the human brain's genes had gone through an intense amount of evolution in a short amount of time - a process that far outstripped the evolution of the genes of other animals.
"We've proven that there is a big distinction," Prof Lahn said. "Human evolution is, in fact, a privileged process because it involves a large number of mutations in a large number of genes.
"To accomplish so much in so little evolutionary time - a few tens of millions of years - requires a selective process that is perhaps categorically different from the typical processes of acquiring new biological traits."
As for how all of this happened, the professor suggests that the development of human society may be the reason.
In an increasingly social environment, greater cognitive abilities probably became more of an advantage.
"As humans become more social, differences in intelligence will translate into much greater differences in fitness, because you can manipulate your social structure to your advantage," he said.
"Even devoid of the social context, as humans become more intelligent, it might create a situation where being a little smarter matters a lot.
"The making of the large human brain is not just the neurological equivalent of making a large antler. Rather, it required a level of selection that's unprecedented."
Guardian Unlimited © Guardian Newspapers Limited 2004
Then can I assume that in Asexual species, the 'offspring' are all the same??
And THEN we'll have a REAL pretty pirhana that breathes oxygen??
NIV Psalms 139:19-22
19. If only you would slay the wicked, O God! Away from me, you bloodthirsty men!
20. They speak of you with evil intent; your adversaries misuse your name.
21. Do I not hate those who hate you, O LORD, and abhor those who rise up against you?
22. I have nothing but hatred for them; I count them my enemies.NIV Psalms 140:9-11
9. Let the heads of those who surround me be covered with the trouble their lips have caused.
10. Let burning coals fall upon them; may they be thrown into the fire, into miry pits, never to rise.
11. Let slanderers not be established in the land; may disaster hunt down men of violence.NIV Psalms 141:5-6
5. Let a righteous man strike me--it is a kindness; let him rebuke me--it is oil on my head. My head will not refuse it. Yet my prayer is ever against the deeds of evildoers;
6. their rulers will be thrown down from the cliffs, and the wicked will learn that my words were well spoken.
As compared to.....
...random mutations manipulating the genetics of pre-humans to make human beings.
Shroud of White Sulphur Springs, West Virginia. Goes along with their Buxtehude & Chopin Society drum and bugle corps.
Of course, this doesn't help with the problem of Lilith (even if she later turned up in a bar in Boston.)
Drink lots of cool-aid over the holidays and brush-up on Charlie's manuscripts...or maybe pull an all-nighter over on talkorig.ath
Hope you had a great Christmas holiday. :)
Check out the latest on this subject over at creation evolution headlines: Human Evolution Falsified
Did god create us or did we invent god.
What convinces me "dogs no":
It is the typical evolutionist leap.
Some "bear" has a different proportion of body to leg and bammo, it's a dog.
No further evidence, just an assertion that 'in North America this evolution continued'.
They pat other like minded authors on the back, but no further scientific evidence is produced.
They point to pictures extrapolated from a few bones, and then cite the supposed similarity of the "picture" to something we're familiar with.
My favorite is the one where human DNA and a flea's DNA are 98% similar, so we all must have evolved from the same place.
A vast difference between a schoolyard anecdote and scientific proof.
I encourage you to find books authored by scientists who used to believe in evolution, but have 'evolved' (he he) in their thinking, to understand that person who is their brother, sister, spouse, etc., didn't just rise up after growing tired of being a worm.
Wearing a cheap knock-off of the Shroud of New Jersey.
Asexual species evolve slower than granite, which is why the invention of sex about 800 million years ago sparked a notable speedup of evolution. I think we talked before about the Vendian "sizzle" that preceded the Cambrian "explosion."
Mutations still happen and lines of descent still branch in asexuals but there's no recombination. Lines never cross. Organism A never exchanges genetic material with organism B even to reproduce. A just clones or buds another little A, etc. If it takes 10 mutations to get a feature, all ten mutations must happen in the same line of descent with nothign ever coming in from outside.
Some exceptions exist for bacteria, which rather freely exchange genes laterally even between highly unrelated species. Another exception is that viruses can infect multiple species of higher life, carrying their viral DNA into the genomes. The implications for evolution are still being argued over.
It's amazing that so many evolutionists will go to great lengths to avoid acknowledging God, then quickly give God-status to a theoretical process with a statement like this.
My pleasure. I enjoy a cordial discussion of such things.
The funny thing is just how untrue that is. Young, fertile women have always been attracted to the stupid, violent, cave-man types. It's part of the human mating dance: The male pretends to be tough to attract the female.
It's only by her second or third marriage that she figures out with no genuine threats, her neanderthal is left with slapping her and the kids around.
Happy new year, my friend.
MM
A random, purposeless, undirected process can neither be used for predictions nor explanations. We can neither explain where it's been nor where it is going. Therefore it must be working.
But it does not breed those capable of thriving, overnight. Yes, by selective breeding patterns, you can begin to build up the gene pool again. Ronald Reagan and Margaret Thatcher both improved the conditions for intellectuals to thrive, but they did not undo the damage done by two generations of Socialism that preceded them--and, of course in the British example, the most extreme damage was done by a combination of the battle fields in early World War I--they had an all volunteer army, staffed by those most steeped in traditional values, and with the higher levels of intelligence--and the brain drain to the Dominions and Rhodesia, etc..
And once a nation is depleted below a certain level, it is very, very difficult for leaders to secure conditions for those remaining with higher levels of native intelligence to thrive. When they try, they run the risk of being treated like Bill Clinton treated General Cedras in Haiti. The world is full of demagogues, just waiting to appeal to mobs of ignorant folk, always ready to demonize those intellectuals, whom you imagine.
William Flax Return Of The Gods Web Site
HUH?
Granted that carp in my picture probably ended up as dinner, But carp & goldfish both are alive today. However 1200 years ago there was no such thing as a goldfish
Please tell me you are beyond the "Why are there still monkeys" argument
In any case, your fish have no "substantial" differences between the two.
Define "Substantial"
OK let me guess, Substantial means whatever you define on a case to case basis, always one step beyond whatever evidence is presented to make sure you never have to believe.
Are you blind, here are some substantial differences
2 Bubble filled sacs
Eyes pointing upward and telescope eyes
button eyes
Oranda headgrowth
Larger or no dorsal fin (Note: Goldfish with dorsal fins have concave shaped
fins, While the crusian carp fins are convex)
Double tail
Egg Shaped body
Different colors
Re-arranged and sized swim bladders
Different way of swimming (For swimming 2 tails are not better than one)
Can't survive in each others habitat
Microsatellite markers.of 100 units (Grecian Carp have only 65)
Coarsely serrated dorsal spine
Matt, metallic, nacreous and pearl scales.
To name a few
If we didn't know from historical records that goldfish came from the crucian carp you would never know they were related. There are probably more differences between the fancy goldfish and crucian carp then there are between human & Chimp, besides being both fish I can't think of many similarities between the two.
Plus your evidence is entirely of known Intelligent Design.
Huh? Did the medieval chine's have genetic engineering capabilities I haven't heard about?
There is no difference in the way goldfish evolved as opposed to any other organism. With goldfish it was look pretty or you're dinner. Goldfish evolution mirrors the evolution of many male birds (i.e. peacocks & birds of paradise) except the only difference is people decide what's pretty enough to breed instead of female birds. There's no design, the Chinese didn't set out to create a bubbleeye or an oranda head, random mutations and selection led them that way.
There is a substantial difference between the earliest vertebrate(not a worm) and homo sapiens.
As well as between the goldfish & crucian carp. The only difference is 500 Million years
Simple math, Even if we assume a very conservative estimate the goldfish & the crucian carp are genetically different by only 0.01% (The microsattilite difference alone guarentees they are way more), That would mean that in 1000 years it's possible to change an organism genetically by 0.01% and exploitating that would mean an organism can change 0.02% in 2000 years, 0.03% in 3000 years and in 500,000,000 years you could change an organism by 5000% which is well enough to cover any change from early chordates to human.
Well, assuming a common ancestor, the rat and the mouse both diverged from that common ancestor. The analogy would be two cars starting in Chicago with one travelling to New York and the other to Los Angeles. After a certain period the distance between them is not how far one travelled but how far they both did from the common point. Now if one broke down just outside of Chitown the distance would be calculated from the one still moving. In the case of the rat and mouse, they are both still "moving". In the case of the human and the fossil, guess what?, the fossil is dead. Thus the "distance" in the case of the rat/mouse is 25 million times 2 and in the case of the human/fossil the distance is ~500 million(human) plus ~0(fossil, it stopped "moving" ~500 million years ago).
|
Definition #5 is the working definition.
Huh? Did the medieval chine's have genetic engineering capabilities I haven't heard about?
It is called selective breeding.
Your imaginary numbers are imaginary. In any case, accepting a 2% Human/chimp DNA difference and your imaginary .01% carp/goldfish difference results in a 200/1 ratio. The hypothetical time difference would be 5 million to 1 thousand(I have seen a two thousand number difference, but will accept your number for sake of argument). That would result in a 5000/1 ratio. It is twenty five times larger than the DNA ratio, which I guess implies that Intelligent Design is 25 times faster than "tossing dice". I'm not sure you've given much more evidence with your imaginary numbers than supporting Intelligent Design. The goldfish was designed as were, the dog, the cat, sheep, milk cows, thanksgiving turkeys, spiral hams....
Okay.
Perhaps Alter Kaker can explain in more specific detail how Cynodictis is known to be ancestor to Cynodesmus. Assuming that Cynodesmus is truly a dog, how strong is the connection to Cynodictis? For that matter, are foxes just dogs or are they a unique species? What can be said of a common ancestor to both dogs and foxes?
I'm just guessing, but my guess is that more similar species, those which apparently more recently evolved and which are presumed to have common ancestors, would provide more fossil remains, since natural processes can destroy fossils over time but there is no way to re-create a fossil once destroyed. There would then be more evidence of an evolutionary link between dogs and foxes than between dogs and bears.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.