Evolution and mitochondral DNA?
486147
Many people have misunderstood the significance of mitochondrial Eve. Dr. Allan Wilson and his team compared mDNA in living people of different racial backgrounds and concluded that all modern humans evolved from one ‘lucky mother’ in Africa about 200,000 years ago (not 10,000 years ago). Researchers named this woman 'Eve' because she sat at one evolutionary bottleneck for humans, but her real name certainly not Eve and there were probably many other “Eves” – at other evolutionary bottlenecks. However, using that name became quite a news event and researchers capitalized on this fact to acquire more funding. The lucky mother's existence, as well as all of the 'unlucky mothers' who's lines did not survive represent strong evidence in support of biological evolution, an ancient earth, and all things scientific (btw - the ape has never been and is not now considered a human ancestor).  \n\nTo answer your question, the mitochondria in any animal population are the same but not exactly that same. Ape populations have the same mitochondria as humans but there is divergence – evolutionary distance. Just as our DNA sequence is the same (with variation) the mDNA sequence is the same but has variations. You should realize researchers are only measuring a small piece of the mDNA on a portion of the molecule where they expect al lot of variation – nobody has looked at the entire sequence – even more differences would emerge in that case.\n\nOn another note, the mitochondria you mention represent another line evolutionary evidence. Dr. Lynn Margulis has advanced the theory of endosymbiosis that explains the mysteries of mitochondrial DNA. Mitochondria were assimilated in eukaryote cells who knows how long ago and selective forces have shaped them into an amazing tool now used to trace evolutionary patterns. This technique is still in its infancy and we can expect to see groundbreaking work as evidence accumulates and more genes are included into the analysis.\n\nConcerning my statement - \n"The ape has never been and is not now considered a human ancestor." Once upon a time 5 or 10 million years ago (or more), in the rift valleys of Africa, there were bipedal animals that did not live in trees - they weren't monkeys or apes or baboons or chimps but they walked on 2 legs. Modern people would call them ape-like but they weren't apes (apes didn't yet exist) and they weren't humans. There's nothing like them now, they've gone extinct, but they were the common ancestor of humans and the great apes. The populations of that common ancestor diverged genetically. One part of the population, after millions of years, give rise to the modern great apes; herbivores that live in the deep forests. Most of the ape species that derived from this population are now extinct. Eventually our common ancestors died out completely, but not before part of their population, after millions of years and a few genetic bottlenecks, left Africa and migrated throughout the old world. They were omnivores and lived more in the open. As they migrated, they continued to change. They met other populations that had also left Africa and they mixed, sharing genes, changing through the millenia. Some of them, eventually became us, most of them died out. So apes are not our ancestors but we do share a common ancestor; apes have diverged as much as we have from that original group but along a very different path.
886021
Evolution and the means to survive.
857229
they think that they evolved from bacteria.  Mitochondria and chloroplasts have their own DNA and manufacture some of their own proteins, like bacteria. It is thought that the mitochondria and chloroplasts evolved from symbiotic bacteria that took up residence inside the first eukaryotic cells.
777562
Presence of Mitochondria\nCilia or Flagella used for cellular locomotion\nPresence of RNA
712484
I searched the ultimate source of all the stuff on net and here's what came out-\n\nhttp://scholar.google.com/scholar?q=humans%20and%20shark%20dna&hl=en&lr=&oi=scholart\nhttp://www.google.com/search?hl=en&q=humans+and+shark+dna\n\nGood luck
1022986
Two potentially unresolved questions in evolutionary biology are how and why did sex evolve (the big unresolved issue), and why only two as opposed to more sexes is stable. theory allegedly predicts three is more stable and better than two for example.\n\nYour text book anwsers, like recombination to break the linkage between "good" and "bad" genes and to avoid parasites (red queen hypothesis) explain why sex, ONCE it has evolved, is stable and selected for, BUT not how or why it evolved.\n\nPerhaps you should consider work by Lynn Marguilas et al. on the symbiont theory. Although now largely accepted that organelles like the mitochondria and chloroplast are degenearte symbionts, and less accepted that the nucleus is too, extrapolation of this theory would allow (account for) for the evolution of diploidy and reductive meisois (and thus sexual reproduction) by having two organisms (one aerobic the other anerobic) merging and seperating according to the oxygen levels (oxygen was at first a highly toxic compound to life untill aerobic metabolism evolved). \n\nBy the way hemaphrodites are still sexual, even selfing ones.\n\nAnd additionaly please note and remember for future that sexual discrimination, like homosexual discrimination, and so on, is neither a prerequisite nor a product of sexual reproduction.
790810
Every fossil, every observation in biology points to evolution. There is nothing that goes against it or points to a different way to scientifically explain modern diversity. There is not one fossil or one piece of DNA that does NOT point to evolution.\nCreation relies on a lot of belief and the ability to dismiss all the known evidence, since ancient Greece to the present time, in the case for evolution.\nEvolution, on the other hand, keeps presenting solid evidence, regardless of those who believe otherwise. \n\nHere is a theoretical example of natural selection and adaptation.\n\nSay you have an island, about twenty miles from any other island, where there is a species of bird, say finches. In any population of birds, there is going to be a variety of beak sizes and wing sizes, (like nose and ear size, and height variation in humans), suddenly there was a drought, lasting several years, and the main food source of the finches, say, sesame seed, was destroyed, and all they had to eat was wheat, which is harder to break and eat than sesame. \nWhat characteristics would give one bird an advantage over another? Those with smaller beaks would have more difficulty cracking the wheat and feeding it to any baby birds, therefore they would have less live young. Those with largeer, stronger beaks would crack and eat more wheat and have more live young. Chances are, that their offspring would have, on average, larger, stronger beaks than those of small beaked finches. The stronger your beak, the more you eat, the more children you have. \nSo what other characteristics? Those with stronger, larger wings could try to find other food, but if they can't make to the other island, they die, those that make it to the other island, and if it has food, will have, on average, larger wings than those that didn't make it. They wil have more children, who, on average, will have larger wings.\nThese are simplified examples, it is more complex than this, but the basics are there.\n\nAnother, real life example is the Peppered moth.\nHere is the Wikipedia link\nhttp://en.wikipedia.org/wiki/Peppered_moth_evolution\n\nThis is evolution at work.\nRead more about evolution, but do it with an open mind. It wiil be of no use looking at evidence if you have already decided to reject it. Remember, you are doing science, at that is what scientist do. The more you read, the more you will understand. Try "Origin of Species " by Charles Darwin as a start, or try Google for a summary.\n\nGood luck to you.
325191
Actually it makes perfect sense.  Things naturally pair together, whether it be by gravity, magnetism, parasitism or whatever reason.  eventually enough atoms will link together for convienience to form a protein, enough protiens will link together to form a cell, then we have life.  cells will then pair together to form tissues, which will pair with other tissues to increase their survival rate giving us more complex organisms.  See the steps yet?  Following that we get to higher functioning organisms.  An organism's cells reproduce millions of times in that organisms lifetime and every time the DNA is replicated there is a chance for a mistake.  How many typos do you make typing a paper?  This is where variation comes from.  Evolution and extinction come from natural selection.  As the world changes things have to adapt those that don't die. If they didn't die we wouldn't call it evolution.
1036246
right on, I'm glad someone else sees some of the problems with evolutions.  Everyone else, keep in mind that this protein is just one of millions that is vital to life as we know it.  And another thing how do we know that the world is 4 billion years old?  Carbon dating?  The half life of carbon 14 is 5,730 years.  So how many half lives is that. Simply put by 4 billion years there no carbon 14 left to measure, it would have all deteriorated.  There is no way that all the life on earth could have resulted by evolution\n\nOkay to everyone above, to the person who said that scientists have created living cells from nonliving molecules, slap yourself because that is an absolute falsehood.  Next when you say that scientist created amino acids that is true but lets look closer.  There were only about 5 different amino acids that were created not all the ones that are necessary for life.  Next how were all the other cell parts (lipids, nucleic acids, carbs) formed.  Did they just appear? Scientists cannot make lipids from just the molecules needed to synthesize them.  I have a very hard time believing that all these parts were formed, in the same place (it is very hard to keep things together underwater let alone in an ocean) and somehow all came together and then replicated.  No that does not happen.  \n\nNext how did new material get added in to the gene pool? Mutation?  Well everything that we know from science (Medicine, genetics) tells us that mutation is bad.  Name one good mutation.  Not sickle cell anemia.  First of all sickle cell is only beneficial when it is in the heterozygote and so it helps protect against malaria, it also cause way more harmful symptoms than beneficial ones.  Look at what happens with people that have cystic fibrosis.  There are a few (less than 10) nucleic acid changes and it is usually fatal.  Mutation does not, repeat, DOES NOT, provide helpful change.  Another thing is how did this first cell survive?  Even the simplest cell carry out complex reactions, and processes that "Scientists" cannot explain after years of study.  In order for this "first cell" to be viable all these pathways would have to present before the cell could live.  And what about all the proteins need for DNA/RNA replication?  There are about 150 different proteins that carry out karyokinesis alone and then comes the problem of separating the DNA.  Come on do you still think that all this could have happened by chance?  \n\nNext time, do not come after creationist because you do not want to believe that there is a God.  With creation everything fits.  The more you know about biology the more you see the holes in evolution.
1099264
you seem to be so smug in your belief of evolution.  there is no proof whatsoever of it happening.  adaptation is different.  bacteria becoming immune to antibodies is adaptation.  humans do this all the time.  the bacteria aren't changing into anything different, they are still bacteria.  \nthere is no evidence in the fossil record either to support your idea.  in fact, all evidence in the fossils says otherwise.  there is no common ancestor of humans and primates.  nowhere.  lucy was an oversized chimp.  neanderthal man is equivalent to modern man in brain capacity, body structure, and everything else, what's the difference?  you can't use the tooth of a pig to create an entire skeleton of a human, that is called fraud (piltdown man).\n\ntry these FACTS: dr. frederick hoyle did a study on the probablility of a single-celled lifeform through means of random process from the beginning of time.  the likelihood of this happening is 1 in 10 to the 40,000 power.  (anything over 1 in 1050 is considered scientifically impossible).  hoyle stated, "evolution is nonsense in the highest degree"\nthe co-discoverer of DNA, francis crick; did a similar study on the chance of one single strand of DNA happening by random chance, but the results came that the chance is so small that it is nonexistant (so close to zero it's actually there)\n\nthe alternative? intelligent design.  all evidence points to a young earth.  if the earth is millions of years old: why hasn't it stopped spinning yet?  it slows down every year?  why hasn't the sahara desert taken over the plant yet?  it's growing by the day?  why have we never seen a single star form?  why hasn't the moon left us yet?  it gets farther and farther away every year?  \n\nother science would ask: why do some heavenly bodies rotate counter-clockwise if they all resulted from the big bang?  (according to the LAW of angular conservation, they should all be spinning the same way)  why isn't there a huge vacuum (present after any explosion); but the universe is instead expanding?  (refer to newton's LAWs of relativity)  why would the population curve put the start of humanity at about 4500 years ago, if we've been around for millions?  why is the oldest tree (also the oldest living organism) only 4500 years old?  \n\nuse evolution to explain morality, emotions, intelligence, abstract thought, love, etc.  you can't.  the only plausible answer is intelligent design.  \n\nanthony flue, once the greatest known and most highly revered atheist; writing over 30 books on the subject is an oxford double-doctorate with numerous other degrees and awards.  now a theist.  the clincher?  intelligent design.  unless you think that you're smarter than this guy (and it doesn't look like it from your grammar, spelling, and theology)  study a bit more before you go bashing theists.  \n\n"when science finally comes to the top of this mountain of truth, it will see that religion has been there all along."
533795
evolution. Or perhaps speciation.
1154759
Post an addendum to your question - you don't need a whole new question.\n\nLeoin is obviously blissfully unaware (or more likely doesn't want to hear) that man and ape SHARED a common ancestor and evolution is based on branches not strength lines.\n\nOne more bit of amateur science to try to bolster an obviously wavering faith.
395275
In nature, living things evolve through changes in their DNA. In an animal like a chicken, DNA from a male sperm cell and a female ovum meet and combine to form a zygote -- the first cell of a new baby chicken. This first cell divides innumerable times to form all of the cells of the complete animal. In any animal, every cell contains exactly the same DNA, and that DNA comes from the zygote.\n\nChickens evolved from non-chickens through small changes caused by the mixing of male and female DNA or by mutations to the DNA that produced the zygote. These changes and mutations only have an effect at the point where a new zygote is created. That is, two non-chickens mated and the DNA in their new zygote contained the mutation(s) that produced the first true chicken. That one zygote cell divided to produce the first true chicken.\n\nPrior to that first true chicken zygote, there were only non-chickens. The zygote cell is the only place where DNA mutations could produce a new animal, and the zygote cell is housed in the chicken's egg. So, the egg must have come first.
1036079
read this and diside for you self \nIt's understandable why some people think that humans evolved from ape-like creatures, but how is saying that complex life forms arose spontaneously from molecules floating around in the sea any more plausible than myth? There is no proven mechanism by which molecules can give rise to simple organisms that later give rise to more complex ones like dinosaurs, just because evolution can happen among very closely related species. A single mutation\nhas very little chance of benefiting an organism, so the chances that millions of organisms can have the right combination of mutations to adapt to their environment is pretty much none. If you try to write a working code for a computer program by wildy mashing buttons, you will not make any progress even if you had all the time in the world. Evolution is the default theory based on process of elimination, for lack of a better explanation without using religion. Evidence of evolution or religion doesn't always have to exclude the other.
282820
What are the major taxonomic categories that we use to organize all life on earth -- species, genus, family, order, phylum, etc?  How many Kingdoms are there and how are they determined?  Give the full taxonomy for Homo Sapiens.\n\nWhat is DNA?  What is RNA?  Describe the steps of RNA transcription.  What is mitosis?  Decribe the steps of mitosis.  How is this different from mieosis?\n\nWhat is a gene?  What is the difference between phenotype and genotype?  What is a dominant gene?  What is a recessive gene?  Why is a dominant gene dominant?  What are the other kinds of gene relationships (co-dominance, etc.)  \n\nDescribe the Theory of Evolution.  What was the evidence Darwin found to come up with the Theory.  How do species evolve over time?  What is speciation and give three examples of how different species can evolve?  What is mutation?  What other times of gene changes are there that are related to evolutionary development?\n\nWhat is an ecology? What are the various types of relationships between species (predation, parasitism, mutualism, commensalism, etc.) and give examples of each. What sort of defenses do species develop against predation?  What sort of features do predators develop in return?\n\nWhat is reproduction?  What are the different kinds of reproduction?  How does reproduction differ between various plant species?  Between animal species?  What are some examples of (I forget the term but) animal features/behaviors that serve only to help with reproduction?  How do these evolve?\n\nWhat is a bacteria?  What is a virus?  What are the differences between prokaryotes and eukaryotes?  What are the major organs in a prokaryotic cell/organism?  How about a eukaryotic cell/organism?  What do each of these do?  What is the current theory on how mitochondria evolved?  What is special about the cell wall and how does it allow material to get across it?  What about the cell nucleus?\n\nWhat is involved in genetic science?  What sorts of things can genetic science do and what are the tools?  What is gene splicing?  What is genotyping and genetic sequencing?  How do these work?\n\nDescribe the major organs and organ systems in the human body.  What is the function of each?  What is the structure of each.  What are some examples of tissue types and how do you recognize them under a microscope?  What are some of the major diseases that humans suffer and what are the symptoms and cures for each?  How is food processed by the digestive system and which food elements are digested in which organs?  What are the more important hormones and neurotransimitters in the human body and what does each do?  \n\nDescribe the different groups of organic molecules important to life -- proteins, carbohydrates, lipids, etc.  What is the molecular structure of each and how are they different?  What is the importance of each and what is their function in the human body?  What is an amino acid?  How many are there, and what do they do?\n\nAnd so much more ... sheesh.
341693
The mother and child will have *nearly* identical DNA.  There will be a few mutations because mutations are ubiquitous, but 99.99+% of their DNA will be the same.
289750
DNA contains in the code itself a remarkable system of redundancy and mutability that allow it to evolve rapidly while protecting against lethal combinations.  This system seems to have been in DNA since the earliest organisms, and has been passed from organism to organism relatively unchanged for 2 billion years.\n\nRead the full article below for all the particulars.