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Posted by: shivani Feb 10 2006, 10:43 PM

I was watching a program , which suggests that Apes evolved into Homo Sapiens, not only because of adaption, but also that the process was driven by some genes inside us. We remembered what we have to become, and that memory helped us become human.

But the process is not yet over. We are still evolving.
Most of the information available is in french though .

Any other info on same??

MJ ???

Posted by: Mandrake Feb 10 2006, 10:58 PM

Will post some thoughts tomorrow.... time to sleep :yawn:

Posted by: shivani Feb 10 2006, 11:01 PM

neend ud jaye teri chain se sone wale

Posted by: bibhas Feb 11 2006, 10:46 AM

Personally, I find this very hard to believe. In my opinion, evolution is not directed. It, however, appears to be so due to the selection pressure which confers specific survival advantages to the species that adapt and wipes out the ones that don't.


This part though, I believe, is accurate

-B

Posted by: Mandrake Feb 11 2006, 02:02 PM

Bibhas comes out of Hibernation. Time for me to go there

Posted by: shivani Feb 11 2006, 07:21 PM

.. rather take me along as well..

Posted by: bibhas Feb 12 2006, 07:08 AM

tum donon hibernation mein gaye to mera yahaan aane ka kya faayda? Ruko, main bhi tumhare saath aata hoon.

Posted by: shivani Feb 16 2006, 05:14 PM

mmm I too am skeptic about it.. but then it could be a possibility and cannot and should not be just brushed aside.
Tried a lot to find more info on this, but its all french to me (literally).
Either of you found more material ?

BTW Bibhas they mentioned that the genetic memory was specifically stored in the jaw area (dont remeber which part of it exactly). Different parts of body contain different kind of genetic information ???? Kind of strange.


Ji bilkul nahi.

Posted by: Mandrake Feb 16 2006, 06:18 PM

Since Bibhas is a biologist by profession, I wouldn't dare to discuss things on an unscientific basis with him. Hence I was resisting from putting my thoughts here.

But, on second thoughts, I think it would be interesting to put them here anyway

I have tangled with Bibhas earlier on this issue too, where I stated that I do not believe in the evolution theory.
Almost an year later, nothing has changed in my belief on that.

And about the point that our genes 'remember' what we are supposed to be only reinforces my pet theory of genetic time-locks. That our genes have encoded data that will be available to us only when we cross a certain number of biological years.

Besides, the Human Genome Project has thrown up some mind-boggling surprises that make is take a solid second-take on what we had thought/assumed so far, only complicates matter further...

That inspite of the so-called 'evolution' we still use only 10% of our brain should really start us thinking. Why, as per the rules/laws/whatever of evolution, the unused 90% didn't shrink into nothingness? Why does the brain have no sensation like other parts of the body?

No, I don't think we understand ourselves yet. So the Homo Futuris will certainly happen, but with a major surprise embedded in there: Homo Futuris will surprisingly be Homo 'Pastis' , the man we've all known before - the kind of people that existed as mentioned in the epics - those who could harness mental powers... those who realized that nature had to be protected, as it was a key element....

Posted by: shivani Feb 16 2006, 06:46 PM

MJ .. you are biased.. I cant trust you.
Please post the links

Posted by: Mandrake Feb 16 2006, 06:57 PM

1) Biased? For believing in something strongly after thinking over it for years?
I'd rather call those biased who believe in evolution, where not a single shred of evidence has been uncovered about the changeover from ape to man. No fossil records, no oral records, no references in any of our mythologies, no nothing... just pure belief!!

I'd rather be biased my way than that way

2) You don't trust me... I know that. You perpetually make me shrivel in my shoes, reminding me that immortal line of Seeta "dharti maa, mujhe apne andar samaa ley"

3) Post links?.... to what?

4) and after whatever you wrote about me in the preceding post, why post links?

I rather sever my links with this thread....

(M's latest car cd-player goes into 'attenuation off' mode. KK croons heart-brokenly:
teri duniyase hoke majboor chala-a-a-a-a
main bahut door, bahut door, bahut doooooooooooooooor chala....)

Posted by: shivani Feb 16 2006, 07:03 PM

sigh! mahanautank.


sharaft se links post kijiye.. and aap kahin nahija rahe hain.
Unless you and Bibhas thrash it out how would I learn

Posted by: bibhas Feb 19 2006, 12:08 AM

No Shivani. I'll have to learn French for that !
Let me explain what I mean when I say "evolution appears to be directed due to the selection pressure".
Let's say you embark on a home decoration project and decide to decorate part of your living room with conch-shells. So you go to the beach searching for some. Since you want them to "match" the decor of the rest of the living room, you choose only to collect those that are perfectly spiral and off-white with choco-brown streaks on the body of the shell. It takes you a while because your criteria are tough but eventually you find enough, discard the rest and decorate your room with them. A guest who has never seen a conch shell in his life arrives from Timbuktu and admires your conch-chell collection a lot. How would he describe a conch-chell to his fellow Timbuktuites upon returning home ? A perfect off-white spiral with choco-brown streaks on the body- right ?
See where I'm going with that? In that example you are mother nature who imposed the "selection pressure" of your criteria such that only the "perfectly off-white spiral conch-shells with choco-brown streaks on the body" survived into your living room, because "mother nature" discared the rest. For a person whose world is only limited to your living room (or the fish that was born in the fish tank in your living room), that's what defines a conch-shell. "Mother nature" knows that there are other kinds of conch-shells out but to him or that fish...
We are all somewhat like that fish, because we only see the world as it appears to us, a mere snap shot of the duration of our lifetimes. We don't know all the processes that went through to make us what we are. It's easy to believe that our genes or somebody knew what we should be like today and constructed us to be so. But it's nothing more than the criteria that were imposed on our ancestors that brought us to Mother Nature's living room. The only difference is that you tossed back the conch shells into the ocean, being the bade-dilwali that you are, but "Mother" is really a cliche for Nature, and being the really tough taskmaster she is, all the ancestors that didn't make the cut were simply eliminated from the planet!


I'd like to see their scientific rationale behind that conclusion! Genetic "memory" is nothing but DNA, which is present in every single cell of your body, all over the body.

Posted by: bibhas Feb 19 2006, 12:55 AM

MJ, aap jaise "ashtavadhani" ke munh se aise shabd achche nahin lagte.


Wow! Has it really been that long? Chaliye, let me hope the 2006 edition will be more successful.


Would like to hear more about that theory sometime, we did touch upon it last year.


IMO this is one of those sayings that's not to be taken literally. The following is the way I interpret it based on my knowledge of neuroscience. The 10% use doesn't mean we are only using one part of the brain and not the rest. How do we use our brain? For every little act of the brain, we make connections between nerve cells called "synapses". The more synapses we associate with a particular event or task, the better we remember it or perform it. What we think of as "100%" refers to the potential number of synapses that can be formed in a human brain. We use varying amounts of that potential depending on the needs of our everyday life and the stages of our life. We discard old unused synapses and we continue to make new ones as our needs change. What does it mean to be using 100% of your brain? Simply using up all of the potential I am talking about. Do we really want to do that? Because that comes with its own onus of having to maintain all of the information and ability which needs additional resources. With the amount we use now, the brain already consumes a majority of the nutritional input of our body.
Think of it as your 100GB hard drive which is full with music you've been downloading from HF. And then Unni uploads a Gigabyte of music you're dying to download. What are your choices? What would you do (assuming you don't have the ability to add more gigs)? Wouldn't you rather have all that memory as "potential" space to download the music you love and only use part of your hard disk and fill it with music that you actually listen to, rather than fill it up with music that's melodious but you don't listen to for whatever the reason might be? If you do choose to do this, would you simply eliminate all the unused space on your HD?


Au Contraire, Brain has all the sensation and there would be no sense of sensation without the brain! When Bhabhiji holds your hand on valentine's day, how do you know that ? The sensory nerve terminals on your palm are sending electrical impulses to your brain which interprets them, decodes them and then tells you via return impulses through the motor nerve that controls your hand muscles to return the gesture by pressing on her hand gently. If your brain did not exist, then there would be nothing but a few microamperes running through your body! I know I know, that's too much biological mumbo-jumbo, give me some real proof, right? Try this sometime, go into absolute darkness, put on as many blindfolds on your eyes as you'd like and spend a couple of hours like that. Pre-arrange with someone to turn on the lights at some random instant of time during that period. You know that the lights are on the instant it happens! How do you know that? I'll tell you how that happens after you try it and are convinced that you knew when the lights went on with all the blindfolds on your eyes.


I couldn't agree more with you on that, my friend!

-Bibhas

Posted by: bibhas Feb 19 2006, 02:18 AM

MJ, remember our discussion last year about Australopithecus, Hominins, Neanderthals etc? I am certain you said you beleived in evolution after that. I am surprised you still think there are no fossil records. I am going to try and defend my view point but I really would like to know why you think no fossil records exist. I am not claiming that there are fossil records of every species that transitioned from pre-ape through the various stages that made the modern man but the amount of evidence available more than makes a well-defined trail.

Following text is a collection of edited quoted material from my evolution resources. I've tried to simplify the text and remove technical jaron to the extent possible.

About 98 percent of the genes in people and chimpanzees are identical, making chimps the closest living biological relatives of humans. This does not mean that humans evolved from chimpanzees, but it does indicate that both species evolved from a common ape ancestor. Modern humans have a number of physical characteristics indicative of an ape ancestry. For instance, people have shoulders with a wide range of movement and fingers capable of strong grasping. In apes, these characteristics are highly developed as adaptations for brachiation (swinging from branch to branch in trees). Although humans do not brachiate, the general anatomy of that earlier adaptation still remains. Both people and apes also have larger brains and greater cognitive abilities than do most other mammals. Human social life, too, shares similarities with that of African apes and other primates that live in large and complex social groups. For instance, chimps form long-lasting attachments with each other; participate in social bonding activities, such as grooming, feeding, and hunting; and form strategic coalitions with each other in order to increase their status and power. Early humans also probably had this kind of elaborate social life. However, modern humans fundamentally differ from apes in many significant ways. For example, as intelligent as apes are, people's brains are much larger and more complex, and people have a unique intellectual capacity and elaborate forms of culture and communication. In addition, only people habitually walk upright, can precisely manipulate very small objects, and have a throat structure that makes speech possible.

Hominoids, (the superfamily of primates that contains apes and humans) evolved during the Miocene epoch (24 million to 5 million years ago). Large ape species had originated in Africa by 23 or 22 million years ago. Among the oldest known hominoids is a group of apes known as Proconsul. Species of Proconsul had features that suggest a close link to the common ancestor of apes and humans. The ape species Proconsul heseloni lived in dense forests of eastern Africa about 20 million years ago. It was agile in the trees, with a flexible backbone and narrow chest of a monkey, yet capable of wide movement of the hip and thumb as in apes.

Early in their evolution, the large apes underwent several radiations, periods when species originated and became more diverse. After Proconsul had thrived for several million years, a group of apes from Africa and Arabia known as the afropithecines evolved around 18 million years ago and diversified into several species. By 15 million years ago, apes had migrated to Asia and Europe over a land bridge formed between the Africa-Arabian and Eurasian continents, which had previously been separated. Around this time, two other groups of apes had evolved – namely, the kenyapithecines of Africa and western Asia (first known about 15 million years ago) and the dryopithecines of Europe (first known about 12 million years ago). It is not yet clear, however, which of these groups of ape species may have given rise to the common ancestor of African apes and humans.

By at least 4.4 million years ago in Africa, an apelike species had evolved that had two important traits, which distinguished it from other apes: (1) small canine teeth (next to the incisors, or front teeth) and (2) bipedalism--the ability to walk on two legs. Scientists commonly refer to these species as australopithecines, or australopiths for short. The name australopithecine translates literally as "southern ape," in reference to South Africa, where the first known australopith fossils were found. Countries in which scientists have found australopith fossils include Ethiopia, Tanzania, Kenya, South Africa, and Chad. Fossils from several different early australopith species that lived between 4 million and 2 million years ago show a variety of adaptations that mark the transition from ape to human.

Most of the distinctly human physical qualities in australopiths related to their bipedal stance. Before australopiths, no mammal had ever evolved an anatomy for habitual upright walking. African apes move around their environments in a variety of ways. They use their arms to climb and to swing through the trees. They knuckle-walk when on the ground, leaning on the middle parts of their fingers. And sometimes they move on two legs, as when chimpanzees feed on low branches or when gorillas show threat displays. The australopith body was devoted especially to bipedal walking. Australopiths also had small canine teeth, as compared with long canines found in almost all other catarrhine primates.

Other characteristics of australopiths reflected their ape ancestry. Although their canine teeth were not large, their faces stuck out far in front of the braincase. Their brains were about the same size as apes' today, about 390 to 550 cubic cm (24 to 34 cubic in) but were enlarged relative to body size. Their body weight, which can be estimated from their bones, ranged from about 27 to 49 kg (60 to 108 lb.) and they stood about 1.1 to 1.5 m (3.5 to 5 ft) tall. Their weight and height compare closely to those of chimpanzees. Some australopith species had a large degree of sexual dimorphism -- males were much larger than females -- a trait also found in gorillas, orangutans, and some other primates.

Australopiths also had curved powerful fingers and long thumbs with a wide range of movement. Apes, in comparison, have longer, very strong, even more curved fingers – which are advantageous for hanging and swinging from branches -- but their very short thumbs limit their ability to manipulate small objects. While the fingers were longer than in modern humans, the australopith finger bones were not so long and curved as to suggest arm swinging. It is not yet clear whether these changes in the hand of early australopiths enabled them to use tools in a better way than earlier apes or even modern chimpanzees today.

Compared with apes, humans have very small canine teeth. Apes, particularly males, have thick, projecting, sharp canines that they use for displays of aggression and as weapons to defend themselves. By 4 million years ago, australopiths had developed the human characteristic of having smaller, flatter canines. Canine reduction might have related to an increase in social cooperation among humans and an accompanying decrease in the need for males to make aggressive displays.

By 2.7 million years ago, the robust australopiths had evolved. The robust australopiths represent an intriguing group of early humans because they survived for a long time and were quite common compared to other early human species. They had adaptations that differed from the larger-brained populations of Homo who lived at the same time. The youngest fossils of robust australopiths are about 1.2 million years old, which suggests that they became extinct by around then. At about that time world climate began to fluctuate in a different pattern, and that may have reduced the food supply on which the robust species depended. Interaction with other early humans, such as Homo erectus, has been suggested as another reason for their extinction, although no compelling evidence exists of direct contact between these species. Competition with several other species of plant-eating monkeys and pigs, which thrived in Africa in the time, may have been an even more important factor. Still, the reasons why the robust australopiths became extinct, after such a successful time, are unknown.

The oldest fossils of the modern human genus, Homo, are at least 2.3 to 2.5 million years old. The evolution of the modern human genus can be divided roughly into three periods: early, middle, and late. Species of early Homo resembled the early australopiths in many ways. Some early Homo species lived until possibly 1.6 million years ago. The period of middle Homo began perhaps between 1.8 million and 2.0 million years ago, overlapping with the end of early Homo. Species of middle Homo evolved an anatomy much more similar to that of modern humans but had comparatively small brains. The transition from middle to late Homo evolved large and complex brains and eventually language. Culture also became an increasingly important part of human life during the most recent period of evolution. The key change usually considered to signal the origin of Homo is an increase in brain size, measured by the volume of the inside of the brain case (cranial capacity). The average cranial capacity of modern humans (Homo sapiens) is 1350 cc, although the range of variation is large, around 1000 to 2000 cc. In the possible ancestors of Homo (Australopithecus afarensis and A. africanus) brain size was about 350 to 500 cc.

Paleoanthropologists generally recognize two species of early Homo. The two species, Homo habilis and Homo rudolfensis, overlapped in time and appear to have co-existed in the same region with other early human species. The record is unclear because most of the early fossils that scientists have identified as species of Homo occur as isolated fragments. In many places, only teeth, jawbones, and pieces of skull -- without any other skeletal remains -- indicate that new species of smaller-toothed humans had evolved as early as 2.5 million years ago. Scientists cannot always tell whether these fossils belong to late-surviving gracile australopiths or early representatives of Homo. The two groups resemble each other because Homo likely descended directly from an early species of australopith.

A fragmented skeleton of a female Homo habilis from Tanzania shows that she stood only about 1 m (3.3 ft) tall, and her arms were longer relative to her legs than they were in the australopiths. At least in the case of this individual, therefore, H. habilis had very apelike body proportions. However, H. habilis also had more modern-looking feet and hands capable of producing tools. Many of the earliest stone tools in Tanzania have been found with H. habilis fossils, suggesting that this species made them.

By about 1.9 million years ago, the period of middle Homo had begun in Africa. Paleoanthropologists now recognize three species of middle Homo: H. ergaster, H. erectus, and H. heidelbergensis. Homo ergaster had a rounded skull, prominent brow ridge, small teeth, and other features that it shared with the later H. erectus. The most important fossil find of this species is a nearly complete skeleton of a young male, dated 1.6 million years old, from West Turkana, Kenya. The sex of the skeleton is determined from the shape of the pelvis and by its brow ridges, and an age of 9 to 12 years at death is known by the pattern of tooth eruption and bone growth. It is not known how the boy died. The "Turkana boy" had long leg bones adapted for long distance walking. The length of his arms, legs, and trunk were proportioned as in modern humans, in contrast with the apelike short legs (and long arms) of H. habilis and A. afarensis. This skeleton is remarkable for the evidence it offers of an early human fully committed to bipedality, with no signs of significant tree climbing. H. ergaster had an elongated body, indicating that it was adapted to hot, tropical climates, just as modern humans from the tropics also tend to have long, slender bodies.

H. erectus appears to have evolved in Africa from earlier populations of Homo ergaster, and then spread to Asia between 1.8 million and 1.5 million years ago. The youngest known fossils of this species, from the Solo River in Java, have been dated to about 50,000 years old. So this species was very successful, both widespread (Africa and Asia) and long-lived, having survived for more than 1.5 million years. H. erectus had a low and rounded braincase that was elongated from front to back, a prominent brow ridge, and an adult cranial capacity of 800 to 1,250 cc, an average twice that of the australopiths. Its bones, including the cranium, were thicker than those of earlier species. Prominent muscle markings and thick, reinforced areas on the bones of H. erectus indicate that its body could withstand powerful movements and stresses. Its body was well adapted for bipedal walking. Although its teeth were much reduced in size from Australopithecus, its lower jaw was still quite thick and rugged looking.

The origin of our own species, Homo sapiens, is one of the most hotly debated topics in paleoanthropology. One distinctive group of fossil humans, the Neanderthals, and their relationship to modern humans has been at the center of the debate. Traditionally, paleoanthropologists have classified as Homo sapiens any fossil human younger than 500,000 years old with a braincase larger than that of H. erectus. Many scientists who believe that modern humans descend from a single line dating back to H. erectus use the term "archaic Homo sapiens" to cover a wide variety of fossil humans that predate anatomically modern H. sapiens. Therefore, Neanderthals are sometimes classified as a subspecies of archaic H. sapiens -- H. sapiens neanderthalensis. Other scientists think that the variation in archaic H. sapiens actually falls into clearly identifiable sets of traits, and that any type of human fossil exhibiting a unique set of traits should have a new species name. According to this view, the Neanderthals belong to their own species, H. neanderthalensis.

The Neanderthals lived in areas ranging from western Europe through central Asia between about 200,000 and 36,000 years ago, although recently discovered fossil and stone-tool evidence suggests that Neanderthals may have persisted until 28-24,000 years ago. The name Neanderthal comes from fossils in 1856 in the Feldhofer Cave of the Neander Valley in Germany. Scientists realized several years later that prior discoveries -- at Engis, Belgium, in 1829 and at Forbes Quarry, Gibraltar, in 1848 -- also represented Neanderthals. These two earlier discoveries were the first early Homo fossils ever found.

The Neanderthals walked fully upright without a slouch or bent knees. Their cranial capacity was large, around 1500 cc (slightly larger on average than the brains of modern populations, a difference probably related to their large bodies and lean muscle mass). They were also culturally sophisticated compared with earlier humans. They made finer tools and were the first humans known to bury their dead and to have symbolic ritual. The practice of intentional burial is one reason why Neanderthal fossils, including a number of skeletons, are quite common compared to earlier forms of Homo. Nevertheless, Neanderthals differed from modern populations in certain ways. Their skulls showed a low forehead, large nasal area, projecting cheek region, double-arched brow ridge, weak chin, and an obvious space behind the third molar (in front of the upward turn of the mandible, or lower jaw). Their bodies were distinguished by these traits: heavily-built bones, occasional bowing of the limb bones, broad scapula (shoulder blade), hip joint rotated outward, long and thin pubic bone, short lower leg and arm bones relative to the uppers, and large joint surfaces of the toes and long bones. Together, these traits made a powerful, compact body of short stature -- males averaged 1.7 m (5ft 5 in) tall and 84 kg (185 lb.), and females averaged 1.5 m (5 ft) tall and 80 kg (176lb).

At the same time as Neanderthal populations grew in number in Europe and parts of Asia, other populations of nearly modern humans arose in Africa and Asia. These fossils, considered to be from archaic humans, are distinct from but similar to those of Neanderthals. Fossils from the Chinese sites display the long, low cranium and large face typical of archaic humans, yet they also have features similar to those of modern people in the region. And at the cave site of Jebel Irhoud, Morocco, scientists have found fossils with the long skull typical of archaic humans but also the modern traits of a somewhat higher forehead and flatter midface. Fossils of humans from East African sites older than 100,000 years also seem to show a mixture of archaic and modern traits.

The oldest known fossils that possess skeletal features typical of modern humans date from between 130,000 and 90,000 years ago. Several key features distinguish the skulls of modern humans from those of archaic species. These features include a much smaller brow ridge, if any; a globe-shaped braincase; and a flat or only slightly projecting face of reduced size. Among all mammals, only humans have a face positioned directly beneath the frontal lobe (forward-most area) of the brain. As a result, modern humans tend to have a higher forehead than did Neanderthals and other archaic humans. The cranial capacity of modern humans ranges from about 1,000 to 2,000 cc, with the average being about 1,350 cc.

Scientists have found both fragmentary and nearly complete cranial fossils of early anatomically modern Homo sapiens from Sudan, Ethiopia, South Africa and Israel. Based on these fossils, many scientists conclude that modern H. sapiens had evolved in Africa by 130,000 years ago and started spreading to diverse parts of the world beginning on a route through the Near East sometime before 90,000 years ago.

I apologise for that incessantly long text but I edited out a ton of stuff to condense it thus. But I hope that I have managed to lay out a trail of the evolution of human origin for you.


Now, if I may ask, what is the evidence for that ?

Posted by: anurag Feb 19 2006, 04:37 AM

Bibhas, MJ, so did the evolution take place or not? I could n't understand much of what Bibhas had posted. Though, his own explanations are as lucid as they can be. Bhabhi kaa haath on V-day and the Hard drive metaphors were illuminating.

Need some Engineering like explanation.

Posted by: bibhas Feb 19 2006, 05:46 AM

Anurag,
Nice to see you here. Hope you had a good time at home. While I am sure MJ would say the jury is still out, I firmly believe in Evolution. Evolution happened and is still happening and will continue to do so. That lamba chauda excerpt was an attempt to list much of the fossil evidence that tracks the evolution from pre-apes to Homo sapiens. If you discard all of the technical stuff and simply focus on the characteristics that arise anew in the newly evolved species and the ones that are still in common with the ancestor, you will see the gradual process of one species evolving into another. Hope that helps. If there are particular sections you would like me to elaborate on, please ask.
Bibhas

Posted by: Mandrake Feb 19 2006, 02:29 PM

Bibhas, I haven't gone through the lamba chauda post yet (will do so a li'l later), but just a curious question:

can you help me walk through a generalized time frame from ape to man changeover (or wherever to man)?

I am not a doubter of people's abilities and knowledge, and I wouldn't ever argue with a professional, as you are in your field.
But I wish to satisfy my curiosities, and answer my doubts. From here on, pls pls don't take my doubts and disbeliefs personally. I am in no way questioning your ability. I am only trying to widen the horizons of my 'flawed' understanding of certain processes...

Posted by: shivani Feb 19 2006, 05:36 PM

Bibhas
Thanks a lot.
I understand this is a text compiled by you from different sources? Can you please post the links to those if they are available online. ( I can search, but there is so much out there and makes it difficult to select the material).



That was my understanding as well.. so the doubt. I am sorry, would not be available to provide more information on it as yet. As I said all the sites are french.



mmm.. Brain does control all the nervous system, but what I remember is Brain tissue itself does not feel pain as such. Is it true or am I illusioned by Dr. Lector


MJ & Bibhas

Both of you agree that homo sapiens are still evolving. What makes you say so? and in which manner /direction ?

Posted by: Mandrake Feb 19 2006, 06:05 PM

Sorry to stick to my guns till proved wrong.
But my acceptance of evolution is only in the mental aspect. Call it evolution or learning, but to me, there is still a lot of growth/evolution left in that department. What has never changed and will never change(purely in my opinion) is the physical configuration.

And I am sorry Bibhas, these are just opinions which don't withstand serious dissection - at least not at this stage. (I guess I'll need to go back and re-look at all the thoughts that brought me to these conclusions a long time ago.

Posted by: shivani Feb 19 2006, 06:12 PM

hmmmm
You think human beings are mentally evolving? Have we made any significant progress in past 1000 years?

Posted by: Mandrake Feb 19 2006, 06:20 PM

Yes, backwards

I treat Mahabharat as a true fact. The kind of things that many of them were capable of doing, using their mental powers, seem today just so much fantasy, coz we've forgotten the methods of attaining such powers.

(Am I going along the wrong path in this thread?)

Posted by: shivani Feb 19 2006, 06:38 PM

ummm In your opinion the beings during Mahabharata period were more evolved... and also that we are moving backwards.

So backwards was better or ...?

We seem to be moving in circles

Posted by: bibhas Feb 20 2006, 01:12 AM

Mandrake,
I did not take it personally at all, I was just a little surprised because you had said last year that you were a total believer in the theory of evolution. I am sorry if I came across as aggressive, this is all thanks due to our great american president who is trying to muck with the school curriculum. I am not an evolutionary biologist but this subject is close to my heart. So my ability is not an issue here at all and you are not questioning it, if it exists


MJ, kuch samjha nahin yaar. Will you elaborate on what you mean by this ?


Dissection nahiin kiya to phir kya mazaa MJ? Khair, whenever you say it.


MJ, you've always been very staunch on this and I am very curious about the epics and the fact vs fiction aspect. And I am at that evidence gathering stage in this regard. So I would love for us to be able to discuss this at length and tap into that vast resource that you are. And if you think this isn't the thread, then there is that dormant thread in chit-o-chat that you had opened first for querying Hits. What sayest thou?

Posted by: bibhas Feb 20 2006, 01:42 AM

Humans belong to the group of mammals known as Primates (which includes lemurs, monkeys, apes and humans). The evolution of Primates started about 55 million years ago. Based on the fossil records of the various species of Proconsul (I had referred to this in that lamba-chauda post), the split between the common ancestors of monkeys and apes happened about 20 million years ago. Based on DNA analysis of apes, humans and fossil DNA, the common ancestor of apes and humans is thought to have existed about 5-8 million years ago. At some point towards the later end of this period, the split between apes and humans occurred. I hope you've had the chance to read that long post of mine by now and if you did, you'll appreciate the fact that distinctively human traits did not appear all at once but did so as a gradual process and so it becomes important to define what is considered to be the begining of appearance of human traits. Walking upright habitually and reduced canine teeth size are considered to be the earliest hallmark features that signalled the start of human evolution. And so over the last 4 and 1/2 million years or so, we went from being Australopiths (who were different from apes in pretty much only those two major traits) to being our current species, Homo sapiens.

I hope I answered your question MJ. If not, feel free to ask.

Edit: Added on Feb 20, 2006, 12.55 pm EST
Mandrake- here is a picture that complements the timelines of human evolution. This composite was created by none other than John Gurche, the famous paleo-artist that also brought "Jurassic Park" to life!

Posted by: bibhas Feb 20 2006, 02:22 AM

Shivani, you're very welcome. Couple of years ago, I was at the annual meeting of the Society of Neuroscience and participated in a panel discussion on the evolution of the brain. There were some folks from a Natural History museum somewhere here in the U.S. and they distributed some easy to read material (about the same level as Hawking's Brief History of Time would be to a non-physicist). A while ago, a friend of mine wanted some ape-to-human evolution material and I put together some stuff based on my general understanding of the process but I had used a lot of the text from these museum guys. While responding to MJ's post, I took the easy route and pasted the email I had sent to my friend. Give me some time to lookup their whereabouts and maybe they have a website with the information. Meanwhile, do me a favor and tell me if you thought my post was comprehensible. If it was, then it'll be worth your while reading the material I refer to, otherwise it'll be too technical and I'd much rather try and find a different source for you in that case.


True Shivani, brain doesn't feel most of the senses directly like the skin does. But that doesn't mean it doesn't feel pain, after all people do get headaches, right? It is the brain that's feeling that pain!


I'll take a route different from MJ's because that in itself is an entire topic that merits a separate discussion. The reason I say we are still evolving is because we are constantly undergoing genetic changes through generations. True we haven't seen any significant changes in our physical traits in the last 25000 years but the fact is 25000 is a very small number in evolutionary timescales (refer to the post directly above this). When there is no major selection pressure resulting from major environmental change, then a species is said to have successfully adapted to the environment and lives successfully until the next period of change. Think of Dinosaurs, they had adapted successfully and ruled the planet until the environment changed drastically. Same is true of Proconsul, the ancestor of humans and apes. It thrived well for several million years before things got uncomfortable. So things will change for us too, it's not even been a million years since we became our current selves. However, the biggest evolutionary change has been in the brain and we have become very adept at using it to control our environment and food supply. Nobody has to fend for himself or herself all alone, we live in societies that take care of each other, so we don't find the need to grow a long neck or nimble feet to reach food on the highest branch of the tallest tree.
This is not within the scope of evolution but would you agree that we have grown intellectually over the past few hundred years alone? If that trend continues consistently for a lot longer, it will qualify to contest for a berth in the book of evolution.

Shivani, I also urge to see my posts-http://www.hamaraforums.com/index.php?s=&showtopic=14344&view=findpost&p=137295 and http://www.hamaraforums.com/index.php?s=&showtopic=14344&view=findpost&p=137355-on evolution in your Determinism thread where I have explained why I think we are still evolving.

As for the knowledge that our ancestors mentioned in the epics possessed, if we assume it to be factual, the reasons for its loss are probably more social and less biological.

Posted by: bibhas Feb 20 2006, 02:52 AM

Folks, I would like to know the following:
1. What does everyone feel about evolution being directed? Do you agree or disagree with that? Especially Shivani, you haven't posted your reaction to my conch-shell analogy.
2. MJ, what is your reaction to the brain's 10-90 use-disuse concept after my response?
3. What do you guys think of the brain's ability to sense?
4. Finally, do you agree that evolution is a currently ongoing process?

Posted by: dimps Feb 20 2006, 12:47 PM

A discussion which I read elsewhere, though not directly connected to this topic, but dealing on evolution

DASAVATARAM or 10 avatar of Vishnu is strikingly similar to Darwin's evolution theory also which sounds quite interesting...

Starting with the Avatars as I know ... .

MATSYA - FISH
KOORMA - TORTOISE
VARAGHA - PIG
SIMHA - LION
VAMANA - DWARF
PARASURAM
RAM
BALARAM
KRISHNA
KALKI / BUDHA

Is there a link between the mythology and the scienctific theory ?

check out this link for starters: http://www.becominghuman.org/

You however need a flash player to view the amazing documentary on human evolution.


Attached File(s)
 Becoming_Human_Paleoanthropology__Evolution_and_Human_Origins.htm ( 13.58 k ) Number of hits: 6 by members

Posted by: dimps Feb 20 2006, 12:54 PM

I tried to post the link, but somehow it was coming thro.

Pls try the site I have mentioned and do comment

Posted by: Mandrake Feb 20 2006, 12:57 PM

Interesting observation Dimps.
A few points quickly:
1) Your link is dead
2) Balaram and Krishna were both avatars of Vishnu? Split personality? (They co-existed)
3) After using force to attain peace in almost every successive avatar, I wonder why Vishnu came as Buddha. No chance to show his heroics in that role
4) Kalki - apparently yet to happen, reverts to the sword-wielding, horse-riding persona...

Is Buddha an aberration? Or was is some other god that came as Buddha?

Posted by: dimps Feb 20 2006, 01:09 PM

Hi Mandrakeji (Suhas)

try the link now - I edited my post

The point I was trying to make is :

evolutiion -
Starting with
Fish - waterborne
Tortoise - amphibian - water and land ?
Animal - Varag - pig - land...
Lion - King of forest ?
Dwarf - ealry form of human ?

Yes - Balaram and Kirshna..why would there be co-existense -
omni present ? avatar in more than one place at same time ?

Last one - some say as Kalki and othes as Budha..

which is correct?
Again - no o ffence meant to anyone - but just a point of discussion

Lalitha

Posted by: Mandrake Feb 20 2006, 01:15 PM

Thanx Lalitha - the link is working now. Truly fascinating stuff - whether one believes or not.

And yes, none of us here is getting offended about anything - this is just a discussion going on, and no attempt to transform anybody's mind

Thanx for coming to this thread. You've become a rare species

Pls do grace more of the threads that we visit

Posted by: dimps Feb 20 2006, 01:28 PM

Ya Suhas - will try asmuch as I can..

I did mention in another thread
to Nimmi the reason for my long absence..

2005 being a very bad period for me...
with a head accident and retina detachment
and so eye problem and eye operation and
what not...

Almost 80 % blind during this period
slowly limping back to normal but
unfortunately, I have only
60 % visiion now and - left eye almost blank...
Never say die spirit so meeting life at
full speed...(hi hi hi)

let us wait and see
how this thread develops...
await input from others on this.

Posted by: Nimii Feb 20 2006, 03:52 PM

dimps ab bhi koi improvement nahi hai kya

You must consult shankar netralaya in Chennai It is the best place re!!!!!!!!!!!

N

Posted by: dimps Feb 20 2006, 04:19 PM

Ya Nimmi -
did that also - went to Shankara Nethralaya in Chennai
and underwent whole lot of tests and they
confirmed what Mumbai eye doctor confirmed -

phirbe consulted yet another doctor in Chennai
privately, who works for Shankara Nethralaya -
nothing
can be done now - try and preserve what is left...
is what all advised me.

Can complete EYE ransplantation be done..like they do
heart transplantation? wonder..
I had sent my diagnosis to my cousins abroad to
check up and learnt nothing further can be done

THAT IS LIFE..

Posted by: Nimii Feb 20 2006, 04:31 PM

Sigh! Dimps ye kya hogaya

N

Posted by: bibhas Feb 20 2006, 11:32 PM

Anurag,
Check out the link Lalithaji (dimps) posted. It's a wonderful documentary that talks about everything I wrote and more in a very simple language with pictorial reconstructions of all the species that make the different stages of human evolution. Yes, evolution did take place and this documentary should convince you of that.

Mandrake- Please check the material I added to my post on evolutionary timelines on the previous page.
http://www.hamaraforums.com/index.php?s=&showtopic=19602&view=findpost&p=223507



Lalithaji,
Very sorry to hear about your eyesight. I hope that a solution comesforth soon.
Thank you very much for posting that link to an amazing documentary. Had I found that before, it would have saved me a lot of typing.
The parallels between dashavataras and the theory of evolution are indeed fascinating. Wonder why there wasn't a primate avatar between Narasimha and the first human avatar!

-B

Posted by: shivani Feb 27 2006, 06:40 PM

Lalitha

I am very sorry to hear about the accident... and equally amazed at your spirit and positive attitude. Can only hope that medicine would be able to help you in some manner in near future.
(Still have not found time to look at the link you posted .. would be back later with comments and questions )

I will post my commnets later Bibhas, meanwhile came across these and could not help but share with you guys : ).

Posted by: shivani Mar 4 2006, 11:09 PM

We slowly ascended from lower life forms to what we are today, by a process of "natural selection" from randomly occurring changes. Each change had to prove its worth by surviving the continual battle for existence, being against being, species against species and this process has gone on for many millions of years.
I agree to evolution, but the evolutions to me seems rather well designed.


One thought often nags me.. there are other creatures from the same era, who did not evolve as we did, and they did go through same situation. It can be said that their geographical location was different, and so they did not have to go through the exact same situation that we had to. I still cant wondering if the choices we made were just one of the probabilities or there was indeed a predecided path we followed. Other animals do not have as evolved brains we humans, but they have survived alongwith us under similar circumstances. Humans became bipedal, learnt agriculture and creation of tools, developed language and various other forms of expression. They learnt to build and make efficient use of available resources. All this learning is needed for survival or not, is questionable.



The two had a common ancestor. The two could not have survived far apart from each other. Yet one group drifted far apart from all other species of the era. Adaptation to the environment is a capability of Mammal Brain, and Apes qualify for that as well. The modification of Instinctive behaviour is as well controlled by the Mammal brain, rather than the human brain. Human brain was no different from a chimp's to start with. Their intelligence level was same, yet chimps did not learn that better ways of survival that their cousins discovered/devised. They could also imitate and we could have two similar species living on the planet. But that did not happen. Homo Sapiens came to be the odd one out. The organ that got affected most in their case, their Brain made all the difference, and the process is still going on. Whereas rest all species followed a different pattern, and seem to have more or less stopped where they were. Why did humans came where they are!!


PS : I know I need to read and understand lot more before I can comeup with some real questions. Please bear with my confusion and learning process. I am sure, I would go back and forth in the whole discussion a lot.
PPS : Bibhas, I did not get tiem to go through the link yet. Will read and get back to you with questions. You are not off the hook on that one as yet : ).

Posted by: shivani Mar 4 2006, 11:39 PM

Some more on what I found on how brain functions : ). I agree to your understanding that 10% usage is a myth. -
What does it mean to "use only 10% of your brain?" Does this statement imply that only 10% of the brain's neurons is active at any one time? If so, how could this be measured? Does the statement assume that only 10% of the brain is firing action potentials at one time? Even if this was true, the discharge of action potentials is not the only function of neurons. Neurons receive a constant barrage of signals from other neurons that result in postsynaptic potentials. Postsynaptic potentials do not always result in the generation of action potentials. Nevertheless, these neurons, even in the absence of generating action potentials, are active.

If all neurons of the brain were generating action potentials at the same time, it is highly likely to result in dysfunction. In fact, some neurotransmitters, such as GABA, act to inhibit the activity of neurons and reduce the probability that an action potential will be produced. Massive excitation of neurons in the cerebral cortex may result in seizures such as those that occur during epilepsy. Inhibition of neuronal activity is a normal and important function of the brain. In other words, some areas of the brain keep other areas quiet.

It is also important to keep in mind that neurons are not the only type of brain cell. Although there are an estimated 100 billion neurons in the human brain, there are another ten to fifty times that number of glial cells in the brain. Glial cells do not generate action potentials. Glial cells function to:

* support the brain structurally
* insulate axons
* clean up cellular debris around neurons
* regulate the chemical composition of the extracellular space

Would we behave normally without 90 billion neurons and billions of glial cells? Would we be just fine if 90% of our brains was removed? If the average human brain weighs 1,400 grams (about 3 lb) and 90% of it was removed, that would leave 140 grams (about 0.3 lb) of brain tissue. That's about the size of a sheep's brain. Clinical evidence indicates that damage to even a small area of the brain, such as that caused by a stroke, may have devastating effects. Some neurological disorders (e.g., Parkinson's disease) also affect only specific areas of the brain. Disabilities may arise after damage to far less 90% of any particular brain area. Because removal of small essential brain areas may have severe functional consequences, neurosurgeons must map the brain carefully before removing brain tissue during operations for epilepsy or brain tumors.

Apart from that, in our brain, there are redundant pathways that serve similar functions. This redundancy may be a type of "safety mechanism" should one pathway for a specific function fail. Still, functional brain imaging studies show that all parts of the brain function. Even during sleep, the brain is active. The brain is still being "used"; it is just in a different active state.

From a developmental perspective, the 10% of the brain statement also fails. The adage "use it or lose it" seems to apply to the developing nervous system. During development, many new synapses in the brain are formed. After birth, many synapses are eliminated later on in development. This period of synaptic development and elimination goes on to "fine tune" the wiring of the nervous system. It appears that correct input is required to maintain a synapse. If input to a particular neural system is eliminated, then neurons in this system may not function properly.



Please explain the Question. Brain can feel the physical pain or it also has the capability of thought. What senses are we talking about here?



Human evolution is directly linked to evolution of their brains. In so many centuries, we have become capable of archiving and using the information, but not exactlyt learnt to put it in our brain. Most of it still needs to be learnt. Also, the ability to learn more has not changed, which suggests that over brain has not significantly evolved. OR maybe I do not know of the differences and so not in a position to comment.
It would be nice if you could point out some specific examples, what kind of information is already available now to us upon birth.

Look at the chart above I posted... it indicates, we are still quite young. So yes, we will grow, but how and where, dont know.

Posted by: dimps Mar 17 2006, 11:47 AM

I have been wanting to write something on this...but somehow,
could not find the right opportunity

Pls read my comment in RED...any one ?

Suhas - I am trying to post a link here, in regard to Budha - just a
matter for discussion I am not trying to raise a hornest nest...
it needs a lot of patience to go thro

I was sent the following links.. which I am unable to
read fully - we need someone with knowledge of sanskrit for this
I suppose.. gist of which is..

Buddha is and avatar of Lord Vishnu an none can deny that - the links
of Dashavathara stuti and Dvadasha sthothra
indeed points to that

 dashavatarastuti_2_.pdf ( 81.28 k ) Number of hits: 1 by members


 dvAdasha_stotra_2_.pdf ( 102.49 k ) Number of hits: 0 by members


study these links and you wont deny Buddha as the ninth avatar of the Lord.

Posted by: sri Mar 17 2006, 12:03 PM

Absolutely correct, dimps !!

" Balarama, elder brother of Krishna, was an avatar or incarnation of Adisesha, the 1000-hooded serpent on which Lord mahavishnu reclines in Vaikuntha " - extract from Mahabharata by C Rajagopalachari

Co-existing avatars are mentioned in the Ramayana - e.g., Rama and Parashurama. both avatars of Vishnu - who come face-to-face in the story, and the purpose of Parashurama's avataar comes to an end when he realises that Rama is also an incarnation of Vishnu.

Sri

Posted by: Mandrake Mar 17 2006, 12:06 PM

Yes Lalitha, we have always read that Balaram was the avatar of Shesha, just as Laxman too was.

Interesting points are, Shesha is Vishnu's assistant in many ways, and will always agree to do what Vishnu wants.

But Balaram often is doing things that do not fall in line with Krishna's thinking. For instance, his fondness for Duryodhana is way beyond his fondness for the Pandavas. Also, he isn't a big player on the Mahabharat scene. Why?

I haven't learnt sanskrit conventionally, so this dashaavtarstutistotra is not open to detailed interpretation from me.

But going by general logic, I had said that the quiet and peaceful ways of Buddha do not tie in easily with the avataars. However, it is just a thought. In a way even Waman was a quiet fella...

And if there weren't so many pointers, I'd have been tempted to believe that Shivaji was the Kalki - avatar...

Posted by: vivekpm Mar 17 2006, 12:26 PM

Have heard somewhere that Sheshnag was tired of being younger brother and taking orders and so he told Vishnu that in next incarnation he would be the elder one and ended up being Balaram in Krishna-avataar. Not sure about the authenticity of this story.

Cheers,