Are we evolved from reptiles?

I think I put this in the right Forum, since it deals with evolution. My little brother asked me a question today which I had no answer to. He was examining the back of his hand and noticed it was "Scaly". If you look at your knuckles and close to the rest of you hand, the skin kinda resembles "scales". he asked me if we evolved from reptiles of somesort like the Dinosaurs. I told him surely not the dinosaurs, but that I heard something about fish evolving into land animals, and those land animals evolving into us. So I can't help but wonder now... Could we be evolved beings from reptiles?

Mammals evolved from reptiles. Humans are mammals, hence we evolved from reptiles. Not every reptile, mind you, but the ones that themselves evolved into mammals.

IIRC, true dinosaurs follow a different line than mammals, so we are vaguely related to them.

But that would still leave the age old question...if we evolved from reptiles..why are there still reptiles

Some people are definitely reptillian. I've had the misfortune to be cast into their company on various occasions.

They give off an ice-coldness that your ordinary human does not. I don't think that we are ALL reptillian. Otherwise there would be not a single compassionate one among us.

Originally posted by NetStorm
But that would still leave the age old question...if we evolved from reptiles..why are there still reptiles

Because the reptiles evolved, too. Some reptiles were perfectly fine as they were, such as alligators, so they stayed the same.

Some reptiles mutated into mammals. They survived, and reproduced.

Some other reptiles went on and evolved into 'better' reptiles.

That's a very simplified way of looking at it, but it's the basic idea.

No offense meant, but that question is only 'age old' to people who have refused to actually research the answer.

arn't human brains similar to reptile brains? especially the cerebellum?

Originally posted by NetStorm
But that would still leave the age old question...if we evolved from reptiles..why are there still reptiles

The most important word in that statement is "from". If we evolved from anything, that doesn't necessarily mean the entire lot of things we evolved from turned into people. I think we evolved from apes, but there are still apes around.

Like someone said before, do some research, have some common sense, and it's not really a big question. Though I guess it could be valid, but still the answer is easy to see.

this is simple high school bio. first, there was 1 reptile / dinosaur that had a huge sail on its back for regulating body heat. that guy evolved into mammals / mice, which were the first mammals. mice evolved into some arboreal primitive monkey, then apes, then humans

Originally posted by Faisca

Originally posted by NetStorm
But that would still leave the age old question...if we evolved from reptiles..why are there still reptiles

Like someone said before, do some research, have some common sense, and it's not really a big question. Though I guess it could be valid, but still the answer is easy to see.

I don't think I said WE DIDN'T evolve from reptiles...I asked --why did they stop--

My "research" so far has found this

All living organisms share the same family tree. This fact is backed by evidence such as:
Archaeopteryx, a missing link between reptiles and birds
mammalian hearing structure, which evolved from reptilian jawbones
the animals of the Galapagos, isolated from the rest of the world
DNA profiles of life forms, present and past

www.actionbioscience.org...


"Humans share a common ancestor with modern African apes, like gorillas and chimpanzees. Scientists believe this common ancestor existed
5 to 8 million years ago. Shortly thereafter, the species diverged into two separate lineages. One of these lineages ultimately evolved into gorillas and chimps, and the other evolved into early human ancestors called hominids. "

www.pbs.org...

Some of the places I can find that say we "evolved" from reptiles, really can show no scientific basis to their claims, just more of the "Serpent Race" claims

"As long as humanity has kept records of its existence, legends of a serpent race have persisted. These myths tell of a mysterious race of superhuman reptilian beings who descended from the heavens to participate in creating humankind and to teach the sciences, impart forbidden knowledge, impose social order, breed with us, and watch over our development."

www.apollonius.net...


though the Harvard Gazzette does have some interesting stuff

www.news.harvard.edu...

"Found in China, the tiny skull shows evidence that the first mammals evolved from reptiles 45 million years earlier than widely believed. "


That evidence shows that many small species evolved toward the mammal state some 300 million years ago, but most of them died out. "It appears that only one group successfully crossed the reptile-mammal divide,"

that still doesn'y explain why they evolved and why they have not continued to evolve.

or here

genesispanthesis.tripod.com...

In many respect[s], the tritylodont skull was very mammalian in its features. Certainly, because of the advanced nature of the zygomatic arches, the secondary palate and the specialized teeth, these animals had feeding habits that were close to those of some mammals . . . . Yet, in spite of these advances, the tritylodonts still retained the reptilian joint between the quadrate bone of the skull and the articular bone of the lower jaw. It is true that these bones were very much reduced, so that the squamosal bone of the skull and the dentary bone of the lower jaw (the two bones involved in the mammalian jaw articulation) were on the point of touching each other"

If you want to look at it from another point of view..then humans could be de-evolving...my SO who is a neonatal nurse, has told me about 3 ---not 1 ---but 3 "mermaid babies" that they have had in their hospital that look just like little fish...except with human heads (yes I know it is a syndrome called Harlequin Babies)
www.benhaus.com...

...or how bout the little baby that by her description would be considered an alien gray (except this one just had fuild for a brain. Slit eyes, holes for ears andno mouth. Is that a human attempting to evolve and just didn;t make it?
You guys don't have to jump down a persons throat and say "Use common sense, do some research"
I asked a simple question..WHAT stoped the other repitiles from evolving and why have they not continued to evolve,


"Yet we never stop to recognize the almost absurd biases coded into this universal mode and which we need to and have come to change in the last couple of years. No scene ever shows another invertebrate after fishes evolved but invertebrates did not go away or stop evolving! After terrestrial reptiles emerge, no subsequent scene ever shows a fish (later oceanic tableaux depict only such returning reptiles as ichthyosaurs and plesiosaurs). But fishes did not stop evolving after one small lineage managed to invade the land. In fact, the major event in the evolution of fishes, the origin and rise to dominance of the teleosts, or modern bony fishes, occurred during the time of the dinosaurs and is therefore never shown at all in any of these sequences - even though teleosts include more than half of all species of vertebrates. Why should humans appear at the end of all sequences? Our order of primates is ancient among mammals, and many other successful lineages arose later than we did"

www.geocities.com...


"Remember, it is not the amount of mutation or variation that makes a new species. The essential thing is that the new population no longer mates with the ancestral population. On occasion that can happen with a single mutation, but more often it takes the accumulation of many changes--especially changes in habitat and diet--before mutual separation results in a new species. When comparing a living species with a possible fossil ancestor, we actually don't know sometimes whether they could have or would have mated or not"

killdevilhill.com...

Theres several diferrent ways to look at this...sorry if my need to understand insulted your inteligence


[Edited on 27-4-2004 by NetStorm]

Dang... I didn't expect to start a debate
All I was looking for was a simple yes, no, maybe.

NetStorm,
if I understand your original statement, that we don�t know why some reptiles evolved into mammals and some stayed reptiles, well its actually quite simple. The whole matter just requires an understanding of mutation and natural selection; the process that we call evolution. evolution has 2 parts. mutation, the first part, is a random and quite accidental phenomenon that results in a variation of genetic structure from a sister group (ancestral species) to a new phenotype (or genotype in some cases). these mutations occur all the time, and most of them aren�t very helpful. but then again some are. this is where selection comes into play. selection is what occurs to siphon off the bad mutations from the good so that only helpful mutations remain in future generations. the survival of the fittest, basically. for example if a mutation causes a species to go blind, then it would have a lot of trouble catching prey, or foraging, or escaping predators. so it wouldn�t survive to copulate, and produce offspring. but, then there are some cases where a blindness mutation would not effect the species chances of survival. like in the case of blind cave fish. they don�t need eyes, because there�s nothing to see, so they are not at a disadvantage, and can go on to make little baby blind fish. this example is similar to the reptile Vs mammal one. some form of reptile mutated into a mammal, but why are some reptiles still left over? well these reptiles simply didn't get selected out. they had what it took to survive, so they stayed with us. now this change from reptile to mammal obviously wasn�t just one mutation, but a very long string which took hundreds of thousands of generations to come about. being as that mutations are rarely helpful, it took a lot of 'trial and error', if you will.
if you meant why did not all reptiles evolve into mammals, well its because mutations are very random, so the chances of the same sequence of thousands of mutations occurring twice is really, really improbable.
I hope this clears some things up.