Ok guys go easy on me ,evolution? but i am clever

[gttjohn]

Hello firstly are Homosapiens evolved from Neanderthals or are we a different all together or
did Homosapiens evolve side by side with Neanderthals did we interbreed ,sorry i know my English is terrible i just have an unquenchable thirst for answers.thankyou

 

[NobodySpecial]

did Homosapiens evolve side by side with Neanderthals

Evolved separately, from a common ancestor species.
Neanderthals appeared first and we evolved later - and then mostly lived side:side for 100,000 years before they died out.

did we interbreed

Almost certainly, some humans have attempted to interbreed with anything that will stand still for long enough.
There is still a question about whether there is any Neanderthal DNA in us today - since we are so similar and Neanderthal remains with surviving DNA are rare it's difficult to be sure

It's possible that the interbreeding didn't produce any children (if our species are too different) or produce infertile offspring so no shared DNA is passed on to us - like a mule being the infertile offspring of a horse and donkey.

 

[gttjohn]

Evolved separately, from a common ancestor species.
Neanderthals appeared first and we evolved later - and then mostly lived side:side for 100,000 years before they died out.


Almost certainly, some humans have attempted to interbreed with anything that will stand still for long enough.
There is still a question about whether there is any Neanderthal DNA in us today - since we are so similar and Neanderthal remains with surviving DNA are rare it's difficult to be sure

It's possible that the interbreeding didn't produce any children (if our species are too different) or produce infertile offspring so no shared DNA is passed on to us - like a mule being the infertile offspring of a horse and donkey.

that very interesting i did not know that about a mule

 

[Dr Lots-o'watts]

We actually have a small fraction of neandethal DNA. Like 1-4%:
http://www.time.com/time/health/article/0,8599,1987568,00.html

But as NS said, we mostly evolved separately. And as far as I understand, we wiped them out (but not necessarily voluntarily, just by being better adapted).

www.gentec-eo.com

 

[NobodySpecial]

We actually have a small fraction of neandethal DNA. Like 1-4%:

It's not quite cut and dried - the tests are tricky.
It's hard to be sure the samples are actually Neanderthal bones and you are using such short fragments it's hard to tell exactly where in the genome they are from - and of course we are so closely related that almost all of our DNA is the same even if we hadn't interbred.

And in evolutionary terms it doesn't really matter very much if we did or not

 

[G037H3]

All humans except Africans interbred with Neanderthals.

 

[Borek]

All humans except Africans interbred with Neanderthals.

Any support to that claim?

 

[Phrak]

We actually have a small fraction of neandethal DNA. Like 1-4%:
http://www.time.com/time/health/article/0,8599,1987568,00.html

Perhaps true, but this is not a convincing article, which seems to be the fault of the Health and Science writer. There is presented no reason why, upon the assumption that Homosapients and Neanderthals are divergent species, we should accept the claim that this common 1-4% DNA is from interbreeding, rather than predivergence DNA held in common

 

[gttjohn]

there is a magazine called NewScientist in the 4th December edition there is some good reading on this subject just picked it up and it is a very good read i can not say if it is real truth or not but a lot of it makes logical sense

 

[Vagn]

there is a magazine called NewScientist in the 4th December edition there is some good reading on this subject just picked it up and it is a very good read i can not say if it is real truth or not but a lot of it makes logical sense

Here's the http://www.sciencemag.org/content/328/5979/710.full" published in Science, vol 238, p710. Unfortunately I don't really know enough genetics to evaluate the paper, so I can't really add any more to the discussion.

 

[Dr Lots-o'watts]

Is it possible that we have a common ancestor with neanderthals? And that the 1-4% common DNA would come from that ancestor?

 

[NobodySpecial]

Is it possible that we have a common ancestor with neanderthals? And that the 1-4% common DNA would come from that ancestor?

We obviously have a common ancestor with neanderthals -we have a common ancestor with every living thing on the planet!
Thats what makes the experiment so tricky, you have to find a bit of DNA that diverged from our most recent common ancestor only in the neanderthal line and then re-appears in our modern DNA.
But since complete genomes of a common ancestor are rare, and neanderthals genomes are rare - and we are so closely related - it's very difficult.

 

[TCups]

I, like most of us I suppose, grew up having been taught the theory of evolution and taking evolution for granted as a scientifically proven fact. But now, as an adult and physician with some background in genetics, mathematics and the laws of probability, I find no credible evidence to suggest that "evolution", occurring as a sequence of spontaneous genetic mutations starting from the DNA of a one-celled organism and ending in the genetic make up of an adult human is mathematically or physiologically possible irrespective of any religious point of view. PS: With what did the first one cell organism interbreed? If evolution is a credible theory, then do we not all have a single ancestor? Doubt it. Just my 2¢.

 

[bobze]

I, like most of us I suppose, grew up having been taught the theory of evolution and taking evolution for granted as a scientifically proven fact. But now, as an adult and physician with some background in genetics, mathematics and the laws of probability, I find no credible evidence to suggest that "evolution", occurring as a sequence of spontaneous genetic mutations starting from the DNA of a one-celled organism and ending in the genetic make up of an adult human is mathematically or physiologically possible irrespective of any religious point of view. PS: With what did the first one cell organism interbreed? If evolution is a credible theory, then do we not all have a single ancestor? Doubt it. Just my 2¢.

You should ask your medical school for your money back, looks like someone didn't get the genetics, mathematics and "laws of probability" the first time around.

It would be more interesting, if rather than interject opinion you could evidence these "impossible" claims with some science. Rather than attempt to argue from a position of authority (not that being a physician with "some background in genetics, mathematics and the 'laws of probability'" makes you an authority on evolutionary biology).

Obviously, you weren't paying attention in medical microbiology when they discussed how ancestrally primitive single celled organisms "interbreed" (read binary fission).

Edit: Not to cast a stone, because maybe you really aren't a creationist, just someone who didn't learn the science they claim to have learned as well as they should--But the argument you are setting up here seems to be the hallmark of those cast by creationists. Namely that arguments from authority are valid detractions from the modern synthesis (normally it seems that anyone with "Dr." in front of their name will do) and that science, like their religions, should follow ancient inerrancy (example; creationists quote scientists "detractors" that may have lived in the early half of the 20th century).

It is my belief that creationists posit such pseudoscientific claims because their religious thinking is so ingrained within them they are unable to divorce the thought process driving their religious thinking from those which drive scientific thinking--Namely that the ancients didn't know best and an "authority's" claims are no more valid than Bobby-Joe the schizophrenics', until they are evidenced in a manner befitting the scientific method.

 

[TCups]

You should ask your medical school for your money back, looks like someone didn't get the genetics, mathematics and "laws of probability" the first time around.

It would be more interesting, if rather than interject opinion you could evidence these "impossible" claims with some science. Rather than attempt to argue from a position of authority (not that being a physician with "some background in genetics, mathematics and the 'laws of probability'" makes you an authority on evolutionary biology).

Obviously, you weren't paying attention in medical microbiology when they discussed how ancestrally primitive single celled organisms "interbreed" (read binary fission).

Edit: Not to cast a stone, because maybe you really aren't a creationist, just someone who didn't learn the science they claim to have learned as well as they should--But the argument you are setting up here seems to be the hallmark of those cast by creationists. Namely that arguments from authority are valid detractions from the modern synthesis (normally it seems that anyone with "Dr." in front of their name will do) and that science, like their religions, should follow ancient inerrancy (example; creationists quote scientists "detractors" that may have lived in the early half of the 20th century).

It is my belief that creationists posit such pseudoscientific claims because their religious thinking is so ingrained within them they are unable to divorce the thought process driving their religious thinking from those which drive scientific thinking--Namely that the ancients didn't know best and an "authority's" claims are no more valid than Bobby-Joe the schizophrenics', until they are evidenced in a manner befitting the scientific method.

Nope, got binary fission, budding, euglenas and such way back in grade school. Understand your position, but intellectually, I still believe it to be not only wrong, but mathematically and physiologically impossible. Neither does entropy tend towards increasing organization nor do spontaneous genetic mutations tend toward more biologically complex, advanced organisms. But thanks for the jab.

 

[NobodySpecial]

Neither does entropy tend towards increasing organization

And yet here you are an organized body of chemicals typing on the internet.
So either the Earth isn't a closed system or there is a big source of entropy above our heads.

nor do spontaneous genetic mutations tend toward more biologically complex, advanced organisms.

How's MRSA and drug-resistant TB doing these days?

 

[bobze]

Nope, got binary fission, budding, euglenas and such way back in grade school.

And yet here you say; "With what did the first one cell organism interbreed?". So either no, you didn't "get" binary fission "way back in grade school", or you're being dishonest. Which is it? You can't have it both ways.

Understand your position, but intellectually, I still believe it to be not only wrong, but mathematically and physiologically impossible.

Yes, we understood this to be your position. Reality cares little for your beliefs however, and you've yet to evidence them in anything but your failed attempt at an argument from authority.

Neither does entropy tend towards increasing organization

And by your same logic, you cannot make ice cubes. A obvious conspiracy by the scientific community at large...

Or, and there is an or, you invest energy into making ice cubes. Likewise there is an energy investment in life. Do you know what this could be? Here's a clue, its big (very big), round (very round), a yellowish-orangy color and lives in the sky.

Surely you've seen this mystical object before? Even back in grade-school you may have learned how a certain type of life on Earth are very adept at using its energy to create organization. And other life feeds off these life-forms and creates its own organization. Imagine that. Must have slept through your medical biochemistry also?

nor do spontaneous genetic mutations tend toward more biologically complex, advanced organisms. But thanks for the jab.

This has been demonstrated again and again, since my Bobze-Spider senses are telling me your access to scientific literature is limited, I'd start here at Wiki; http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment" .

You can also try some of these http://www.gate.net/~rwms/EvoMutations.html"

 

[tkjtkj]

We obviously have a common ancestor with neanderthals -we have a common ancestor with every living thing on the planet!

Well, i can see how you might think that's true, but it doesn't really have to be true .. Yes, every living thing could, theoretically, be traced back to its 'ultimate ancestor', an entity that first got that spark,, the ability to reproduce. But that is not to say the such an event happened only once!
It is possible that it happened many times , so that there could be a largish number of 'life lineages' on our planet, each line having its own 'ultimate precursor life-form'. In fact, the ease with which living things seem to develop out of that 'primative pre-life ooze' suggests that this is more likely to be the case. I doubt it'll ever be possible to prove but science has a way of mocking anyone that believes in any sort of 'impossibility!

 

[Dr Lots-o'watts]

...I still believe it to be not only wrong, but mathematically and physiologically impossible... Neither does entropy tend towards increasing organization nor do spontaneous genetic mutations tend toward more biologically complex, advanced organisms...

Because a physician's theory is obviously better than anything proposed by any biologist's, geneticist's, chemist's, physicist's, mathematician's, or any other scientist's of course... Surely studying how to diagnose and treat the human body gives a better perspective than the one the people who dedicate their lives to the subject come up with huh?

You may own the techniques to heal me sir, but you haven't given any arguments to your beliefs.

 

[gttjohn]

Well one thing is certain you are all very passionate about physics,science a I have learned so much so far from this thread alone,But I am taking what's logical and scientifically proven away with me good so far thanks all

 

[Phyisab****]

Neither does entropy tend towards increasing organization nor do spontaneous genetic mutations tend toward more biologically complex, advanced organisms. But thanks for the jab.

Good grief I swear I've seen this argument on these forums 10 times in the last month.

 

[TCups]

our heads.

How's MRSA and drug-resistant TB doing these days?

But isn't that a "beak of the finch" argument? MRSA is still staphylococcus aureus, and drug-resistant TB is still a mycobacterium, not a protozoan. Environmental adaptation occurs without a doubt and occurs very rapidly. This is a proven observation that I don't dispute.

Speciation if I understand that term correctly -- the "evolution" of one distinct species into an entirely new species -- to the best of my knowledge (obviously limited) has not been observed in any laboratory experiment or ever irrefutably proven by any complete fossil record, fossil records being temporally limited to a few thousand years. And the theory of evolution, I believe (please correct me if wrong) would seem to imply that "speciation" must be a long-term consequence of natural selection, ending in the present biological diversity, but occurring over much longer time intervals than can perhaps be observed experimentally.

As for entropy (and ice cubes) . . .
My poorly stated argument - apologies. May I reframe the argument? How did the first simple biological life form "evolve" from something else? How might DNA (or even RNA) spontaneously assemble itself from simple amino acids and having done so, evolve to become self-replicating and then, ever more complex? Nothing in my education or experience gives me a clue to a natural, physical process that would tend to have this result, least of all, random chance.

Here's another question on my mind: mitochondrial DNA. I know, in general, that it is passed down through the female lineage and links much of our human species to a single female African ancestor. But not only humans have mitochondria and mitochondrial DNA. Has there ever been any inter-species (vs. intra-species) links of the mitochondrial DNA of one species to another species?

Please forgive my skepticism. I know I may be wrong and understand that I offer no alternate hypothesis.

 

[SW VandeCarr]

How might DNA (or even RNA) spontaneously assemble itself from simple amino acids

How might it indeed? You must have missed that class.

 

[bobze]

How might it indeed? You must have missed that class.

LOL--Its okay, he's a "physician with some background in genetics". Nothing he should have known or anything like that

 

[TCups]

Thanks so much guys. I get it. I won't be back to bother any of you. Sorry for being such an arrogant idiot. Perhaps one day I will achieve your mastery of the subject. etc.

 

[DaleSwanson]

But isn't that a "beak of the finch" argument? MRSA is still staphylococcus aureus, and drug-resistant TB is still a mycobacterium, not a protozoan. Environmental adaptation occurs without a doubt and occurs very rapidly. This is a proven observation that I don't dispute.

Speciation if I understand that term correctly -- the "evolution" of one distinct species into an entirely new species -- to the best of my knowledge (obviously limited) has not been observed in any laboratory experiment or ever irrefutably proven by any complete fossil record, fossil records being temporally limited to a few thousand years. And the theory of evolution, I believe (please correct me if wrong) would seem to imply that "speciation" must be a long-term consequence of natural selection, ending in the present biological diversity, but occurring over much longer time intervals than can perhaps be observed experimentally.

If you accept that organisms will over time evolve small adaptions to their environment, doesn't it logically follow that, given a much greater time, these small changes would add up a large change? And that this change could be so great that an organism from the beginning generation would be unable to reproduce with one from the final generation?

As for entropy (and ice cubes) . . .
My poorly stated argument - apologies. May I reframe the argument? How did the first simple biological life form "evolve" from something else? How might DNA (or even RNA) spontaneously assemble itself from simple amino acids and having done so, evolve to become self-replicating and then, ever more complex? Nothing in my education or experience gives me a clue to a natural, physical process that would tend to have this result, least of all, random chance.

The theory of evolution makes no attempt to explain the origin of life. It only explains how once self replicating life existed it could evolve into the wide range of forms we see today.


Have you read Richard Dawkins newest book, http://en.wikipedia.org/wiki/The_Greatest_Show_on_Earth:_The_Evidence_for_Evolution" ? In case you've found his past work to be too aggressive, I can say this one is very focused on evolution and presenting evidence. I don't think anyone would be offended by it.

 

[NobodySpecial]

Speciation if I understand that term correctly -- the "evolution" of one distinct species into an entirely new species -- to the best of my knowledge (obviously limited) has not been observed in any laboratory experiment or ever irrefutably proven by any complete fossil record,

Perhaps the best 'experimental evidence' is ring species. There are species of birds which live around the article circle - the ones in (say) Western Europe can mate successfully with their similar neighbours in Scandanavia, those can mate with their close relatives in Russia and those with the same bird in Japan. But the ones in Japan have differed enough that they can no longer mate with the ones in Europe. Ultimately they would form a new species.

As for entropy (and ice cubes) . . . My poorly stated argument - apologies.

Sorry it's a common creationist argument of misunderstanding thermodynamics and the meaning of a closed system and deliberately confusing the thermodynamic term ordered and the idea that people are 'more' advanced than bacteria.

How might DNA (or even RNA) spontaneously assemble itself from simple amino acids and having done so, evolve to become self-replicating and then, ever more complex?

That is just about demonstrable in the laboratory. There are self catalyising chemical reactions where the product of the reaction makes the reaction work more effectively. There are even ones which have different pathways depending on the conditions (acidity/ temperature/ etc). So a given reaction produces more stuff that makes itself more likely - it's not hard to go from this level of protein structure to RNA

But not only humans have mitochondria and mitochondrial DNA. Has there ever been any inter-species (vs. intra-species) links of the mitochondrial DNA of one species to another species?

Every (I think) multicelled animal has mitochondria - they are probably a bacteria that originally infected our cells and became essential for life. The RNA of mitochondria can be traced back through ancestor animals.

Please forgive my skepticism. I know I may be wrong and understand that I offer no alternate hypothesis.

Science is skepticism - the reaction was just because these arguments normally end with somebody quoting a bit of middle eastern mythology as proof that they are right.

ps. I'm a physicist - I might have some of the details slightly wrong

 

[bobze]

But isn't that a "beak of the finch" argument? MRSA is still staphylococcus aureus, and drug-resistant TB is still a mycobacterium, not a protozoan. Environmental adaptation occurs without a doubt and occurs very rapidly. This is a proven observation that I don't dispute.

No, the argument you are figuring to setup here "micro vs macro" evolution is one perpetuated by the billion dollar creationist industry. Macroevolution is microevolution. They are one in the same process. The only difference is some subjective definition of time elapsed since a coalescent point.

Speciation if I understand that term correctly -- the "evolution" of one distinct species into an entirely new species -- to the best of my knowledge (obviously limited) has not been observed in any laboratory experiment or ever irrefutably proven by any complete fossil record,

Modern "species" don't evolve into other modern "species"--A species is only so by way of its lineage. No matter how many children you have and how different they look from you they will never be the children of a distant cousin. Ergo, bacteria don't evolve into "cats" or "dogs" or "fronkies". And anything that bacteria "evolve" into will always belong to the "kind" bacteria, because bacteria is a rank of organisms which share a common ancestor and will always share said ancestor.

As far as "speciation" goes, the first step to understanding that is understanding that species are not real, tangible things. They are (like the definition of life) a ranking bestowed by people upon populations.

Populations who split can no longer share genes between them. That is to say they are reproductively isolated (searchable term) and therefore any changes modulated to their gene pool will accumulate separate changes. When these changes are enough that the populations no longer interbreed even when brought back together-we say we have "speciation". Because, without interbreeding their lineages will continue to diverge in a manner reflective of the selective pressures on each gene pool.

There are many barriers to gene flow. They can be pre-zygotic, such as a penis not fitting to a vagina, sperm receptors of the zona pellucida differing, behavioral nuances (time of day matting occurs, season matting occurs, mating displays etc) and many others. There can also be post-zygotic barriers, ie; fertilization occurs but the zygote is non-viable, the offspring is non-viable, the offspring is sterile etc.

As for reproductive isolation being observed in the lab? Maybe you are not familiar with http://en.wikipedia.org/wiki/Speciation#Artificial_speciation"?

fossil records being temporally limited to a few thousand years.

I'm not sure what you are stating here, do you mean to say that the fossil record is only a few thousand years old?

And the theory of evolution, I believe (please correct me if wrong) would seem to imply that "speciation" must be a long-term consequence of natural selection, ending in the present biological diversity, but occurring over much longer time intervals than can perhaps be observed experimentally.

No, the modern synthesis simply says that when reproductive isolation is achieved, because of selection, the two gene pools will diverge. Over how long, and under what kind of selection will determine how "different looking" the extant lineages will become.

As for entropy (and ice cubes) . . .
My poorly stated argument - apologies. May I reframe the argument? How did the first simple biological life form "evolve" from something else?

Biological evolution is not synonymous with abiogenesis. Surely, as a physician, you are aware that scientific theories explain specific scientific phenomena? You can no more use relativity to explain fluid flow through a tube, than you could the modern synthesis to explain why the continents move about the surface of the Earth (or the origin of life for that matter). We are talking, apples and oranges--mechanistically speaking.

Nevertheless, the origin of life is still an interesting question that we are still looking for the answer too. There is some things we do know about that origin. For starters, we know that a molecule had to have the ability replicate. Probably through a spontaneous process and later auto-catalysis. We know that the first replicator would have had to have a "book keeping" ability, ie ability to transmit information across generations and that resources spurred competition and differential survival/reproduction of those replicators.

Its for this reason that RNA seems to get the lead role in the search for the origin of life and probably the best supported hypothesis (at the moment) being the http://en.wikipedia.org/wiki/RNA_world_hypothesis" .

We know RNA can be auto-catalytic (recall from your biochemistry classes what rRNA is and does). We know that RNA polymerizes fairly easily (there was an interesting paper on here some time ago about how RNA polymerization would have been very favorable under prebiotic conditions reducing the entropy of the earth-sun system-http://arxiv.org/PS_cache/arxiv/pdf/0907/0907.0042v3.pdf" ) and we also know that RNA can act as a carrier of hereditary information across generations (remember those guys we call RNA viruses?)

How might DNA (or even RNA) spontaneously assemble itself from simple amino acids and having done so, evolve to become self-replicating and then, ever more complex?

Well granting that you meant "nucleic acids" here (I sincerely hope a physician practicing medicine in the 21st century is aware of what RNA and DNA is made of), see above.

Nothing in my education or experience gives me a clue to a natural, physical process that would tend to have this result, least of all, random chance.

You education should clue you into the word "selection" in the phrase "natural selection".

The biological fact of evolution is that allele frequencies for a gene pool change from generation to generation. The is simply the fact. In science, we like to explain facts-because facts by themselves are worthless and tell us nothing about our world or how it works.

The modern synthesis is a scientific theory which explains the biological fact of evolution-Namely that adaptive evolution is driven by natural selection. Implied in this are one of the things Darwin got right about evolution-Namely his "four postulates" of natural selection; That there is variation in a population, that some of that variation is passed on to offspring, that resources in any environment are limited, and that some of those variants will be better or worse at surviving and reproducing than others. Hence, we have differential survival and reproduction--A non-random process.

What Darwin (and Wallace) really discovered was a syllogism of another process that humans had been doing for thousands of years--Artificial selection. Meaning, that humans choose which individuals in a population will pass on their traits to the next generations. Dog breeders, horse breeders, plant breeders, for generations have been using selection to alter the frequency of alleles expressed in a population.

By the same token, non-humans, have also been breeding populations for specific traits. Bees choose flowers for their appeal, herder ants breed aphids and Damselfish breed algae.

Darwin's genius was to realize that there doesn't have to be chooser to determine who gets to pass on traits. The simple observation that animals who die before reproductive age or who reproduce poorly, like a dog you don't breed because it lacks a trait that appeases your sense aesthetics, will "sit out" of the future gene pool. In other words, selection without a selector.

Here's another question on my mind: mitochondrial DNA. I know, in general, that it is passed down through the female lineage and links much of our human species to a single female African ancestor. But not only humans have mitochondria and mitochondrial DNA. Has there ever been any inter-species (vs. intra-species) links of the mitochondrial DNA of one species to another species?

Yes, one only needs to do a literature search on mitochondrial DNA clocks.