Evidence that supports the interference that vertebrates may have evolved from common ancestors?
349428
One of the features taken as evidence that two organisms share a common ancestor is the possession of a number of unique traits that are found in those organisms, and are not found in other groups of organisms.\n\nThe following is a (partial) list of the characters shared by all chordates (the phylum to which vertebrates belong)\n\n- Possession of a notochord (which is a dorsal axial rod of vacuolated muscular cells surrounded by a connective tissue which forms in the blastocyst from the roof of the archenteron).  The notochord functions as a skeleton and resists deformation when muscles contract.\n\n- Pharyngeal gill slits (originally for filter feeding, also for respiration)\n\n- Dorsal hollow nerve cord derived by invagination of ectoderm along the dorsal midline, sometimes with anterior expansion (brain)\n\n- Postanal tail (major locomotory organ in most chordates)\n\n- Subpharyngeal gland, which is secretory tissue in the endoderm of the pharynx floor (endostyle in protochordates, thyroid gland in 'higher' chordates)\n\n- Ventral heart\n\n- Segmented body with segmented axial muscles, axial skeleton, gill arches, nerves, aortic arches\n\n- Ectodermal ciliated canal (endocrine function, pituitary in 'higher' chordates)\n\nIn addition, there are several features unique to the the vertebrates:\n\n- Neural crest cells (arising from neural groove, become melanocytes, sensory neurons etc.)\n\n- Endoskeleton of bone and/or cartilage\n\n- 3 part brain\n\n- Muscular pharyngeal pump\n\n- Jointed internal skeleton (unique in Animal Kingdom)\n\n- Unsegmented gonads\n\n- Usually with a skeletal cylinder protecting the dorsal hollow nerve cord (i.e. vertebrae)\n\n- Pharynx is chiefly respiratory\n\n- Gas bladder for buoyancy control and respiration (in most)\n\n- Paired jaws (in most)\n\n- Paired appendages (in most)\n\n- Cranium protecting the brain (poorly developed in some)\n\nAll of these features are shared between all the vertebrates, from nasty lamprey and disgusting hagfish to cute kitty cats and arrogant humans to giant blue whales and extinct ankylosaurs.\n\nThe possession of all of these features suggests that these organisms share a common ancestor from which they inherited all these traits.
131055
I'd like to think that you're asking this question with an earnest wish to get good informative answers. If that is the case, I invite you to see the link that Kurdiatcha left, or to do a web search for the term, or else, to read some good Evolution textbooks such as Ridley's "Evolution" or Freeman & Herron's "Evolutionary analysis", or Futuyma, or Stephen Jay Gould if you want something more entertaining.\nIf that is not the case, I'm not bothering anymore *sigh*
18310
Probably not.  If you believe in evolution, then remember that animals were laying eggs long before the chicken came along.
864911
Probably not (and you probably mean "ancestors.")\nIt may have been some other lobe-finned fish, or some other fish with limb-like fins.
792821
Yes. See the links below. I highly encourage everyone who doubts evolution to spend a little time browsing the "tree of life  web" site www.tolweb.org. Look both at the tree diagrams, showing how life has evolved into different species, but also look at the titles of the papers that are referenced on each page. For example, from the Primates page, there are papers with these titles:\n\n"Toward a phylogenetic classification of primates based on DNA evidence complemented by fossil evidence. "\n"A molecular view of primate phylogeny and important systematic and evolutionary questions. "\n"Molecular timing of primate divergences as estimated by two nonprimate calibration points."\n"The oldest known anthropoid postcranial fossils and the early evolution of higher primates."\n"Molecular evidence on primate phylogeny from DNA sequences. "\n\nThere is a huge body of scientific literature that doesn't just say "we think we evolved from apes". It explains in great detail the evolution of all life, and shows where humans fit in the families of hominids, primates, and mammals. There is a great deal of evidence, not just from fossil evidence, but from DNA evidence. The DNA evidence is now far more powerful than the fossil evidence.
990517
12 March 2002\n\nPOINTS OF ORIGINS: Variety is the Spice of Life\nby Dr. Glenn Jackson\n\nAmong modern environmentalists the term "species diversity" is a real keyword. Having lots of different species is considered good for the environment. But having all these species makes it hard to classify them all. When you start to talk about all of the extinct species too -- well, it gets pretty crowded. Most evolutionists are fond of pointing out that 95% (some even say 99%) of all species that have ever lived, are now extinct. Let me suggest a thought that may never have occurred to you before. Maybe most of these were just species that didn't make it to survive much beyond the year of Noah's Flood. Maybe all these "weird" prehistoric life forms only look weird to us because we're just not used to them anymore. There is mounting evidence that the ancient world had many more species -- but all living at the same time! -- not all living in vastly different times like the Paleozoic and Jurassic, etc. One entomologist (insect-studier) from Univ of Kansas says, "I never expected to find this staggering array of diversity. It blew me away." Dr. Engel is an expert on bees (Science News, 2/10/01, p87). A newer DNA study has found that crabs "must have evolved at least five different times." (Science News, 3/2/02) Now it's impossible enough to believe that crabs evolved even once -- let alone five times! Bat DNA seems to indicate that echo-location must have "evolved" in bats at least two times -- maybe three. This conclusion even has the evolutionists going batty! I'm serious. This has been driving them nuts. How could sonar have evolved twice? It's so far-fetched to believe that it could have even evolved once! To make matters worse, fossil species are now so many, that the names are getting all confused (Knoxville-News Sentinel, 2/4/02, pE14). I believe that the richness of the Earth's many species of living things today -- is nowhere near what it was before the Great Flood. That would explain why we see fossils of all these "weird" creatures trapped in the rocks left by the debris from the Flood. With all those extra life forms, there were plenty for evolutionists to choose from, while they were looking for all of their "missing links." Well, since they have started to double-check on all of those links, by using DNA, they have found that their best examples really weren't links at all -- but totally separate created kinds, just like the Genesis account predicts. If the scientists would only begin to do their investigations based on the assumption that creation is true and not evolution -- I'd bet that they'd reach their conclusions a lot faster, and things wouldn't be so confusing but would all begin to make perfect sense. Well, "thinking themselves wise they became fools." You keep thinking. \n\n\n--------------------------------------------------------------------------------\n\nDr. Glenn Jackson holds four degrees in science and education from George Mason University and University of Virginia. He has taught elementary through college level sciences for over twenty years and in four states. He is a lifetime member of both American Mensa and the Creation Research Society.
256328
man and monkey evolved from a common ancestor
292034
We all had a common ancestor.  It just so happens that apes evolved differently to suit their environment than humans; we didn't evolve from each other, just divergently from our ancestor
389680
Hey, iloveicecream103, why don't YOU read a book about science, then talk to us about Genesis, if you still can.\n\nFossil layers show change over time.  The lowest layers have species the least like modern species.  As you progress up the fossil record, each layer is consistently more and more like modern organisms.  Creationists have no explanation for this.  They haven't even bothered trying.\n\nComing up the fossil record, you see forms changing over time.  Clams are preceded by animals like clams, but with their shells united.  Before mammals, mammal-like reptiles.  Before reptiles, reptile-like amphibians.  Before amphibians, amphibian-like fish.  Creationists have no explanation for this either, but they have made a few wasted efforts.\n\nThe transitions evolution expects occur.  Creationists can pretend they aren't *really* transitions, they just *look* like transitions, but that's just like a child yelling "DOES NOT" to win an argument.\n\nCreationists especially need to pretend that no transitions between humans and other apes appear.  They claim that all fossils are obviously human or obviously ape.  However, if you examine the claims of multiple creationists, you'll find they disagree on which are "obviously" which.  If it was so freaking obvious, shouldn't they be able to agree?  At least a little?  Here's a chart:\n\nhttp://www.talkorigins.org/faqs/homs/compare.html\n\nThe only thing obvious about it is that the skulls obviously cannot be considered one or the other and must be seen as transitions by any open-minded person.\n\nThe transitions that evolution doesn't want do not occur.  At no point in the fossil record do we find mammal/birds.  At no point do we find any direct transitions between amphibians and mammals.  We don't find any cat/humans either.  Any of these things, if discovered, would scrap evolutionary theory overnight.  Creationists have yet to explain why God made only species that look like they could have evolved.\n\nEven without any notion of progress or change over time in the fossil record, it's sorting would be an embarrassment to creationists.\n\nScientists respect the fossil record and accept it on its own terms.  If oak trees appear on top of tree ferns, oak trees came after tree ferns.  Creationists need to impose explanations to account for their claims that everything existed together at once, but these do not flow naturally from the evidence.  For instance, they have no explanation for why oak trees are found above tree ferns.\n\nCreationists have three explanations for fossil sorting, none of them works at all.\n\n1.  They like to claim that fossils are sorted by which species could outrun the rising floodwaters (they blame Noah’s' flood for everything they can't explain).  This would mean that moles and sloths can run faster than velociraptors, Oak trees and mangroves can run faster than velociraptors as well.  Velociraptors run at the same speed as tree ferns.  It is also useless for explaining why ichthyosaurs and dolphins are never found together.\n\n2.  They claim that different species occur in different ecological zones, thus would form in different layers.  This fails again.  Mangroves are found in the lowest ecological zone of any flowering plants, but the highest levels of the fossil record.  Oak trees are found high with mangroves, instead of low in the plains.  Tree ferns should be found with oaks.  Moles should be beneath velociraptors again, and ichthyosaurs should, again, be found with dolphins.\n\n3.  They claim that the mechanical action of the flood should sort things.  Well, it should.  Too bad such sorting doesn't look at all like what is seen.  Mangroves sink, for example.  So do waterlogged oaks.  Moles are bullet shaped and would sink faster than light-boned velociraptors.  Dolphins and ichthyosaurs should, again, be found together.\n\nCreationists have lots of explanations for fossil so
363668
We didn't come from apes. Apes and humans have a common simian ancestor, but the species evolved separately.
1017223
If we talk about Evolution Theory, a number of them have been formulated till now, for instance, by Lean Bapist Lamark, by Charles Robert Darwin, by Earnest Hackel, by Hugos de Veries....\nBut in general, the probable evidences, which might have stimulated these gentlemen to formulate their Evolution Theory are,\n1) Fossils - Missing links, and connecting links\n2) Homologous organs\n3) Analogous organs\n4) Vestigial organs\n5) Embryology\n\nAnd apart from these, we can take into consideration, "Physiology ".
900194
Divergence leads to different developments in species, even those that share a common ancestor. We didn't come from apes as they are today. We came from an ape-like ancestor (primate) that we share with the apes of today, but there were divergent events at some points in history that lead to the developments of homosapiens and the other various primates of today.
1167804
One of the dangers of evolution is that it makes *TOO* MUCH SENSE.  It is actually incredibly simple and logical!  It makes so much sense WHEN YOU UNDERSTAND IT, that it's tempting to believe it on logical grounds alone, and forget that a good theory not only has to make sense, but it has to have *evidence* to support it.\n\nBut guess what? The evidence is there too! Tons of evidence.  Fossil evidence, genetic evidence, molecular evidence, comparative anatomy, vestigial and homologous structures, geographic distribution of species, etc. etc., all supporting the same idea.\n\nBut purely with respect to the how simple it is:\n\nNatural selection requires three ingredients:\n1. Variation. (E.g. some individuals within a species are hairier/taller/lighter/whatever than others individuals).\n2. Selection. (Hairier individuals do better and make more babies in one environment, or lighter individuals do better and make more babies in another environment).\n3.  Time.  (As in *gobs* of it, millions, billions of generations.)\n\nThat's it.  People who focus on probabilities, or say the evolution is about randomness or blind "luck" think it's all about #1.  Randomness only comes into play as a source of variation.  There's nothing random about the idea that hairier animals live longer and make more babies in colder environments.\n\nAnd there's nothing in there that says that if some members of a species evolve into a new species, that *all* members must evolve (i.e. that the former species must disappear).  E.g., the hairier individuals may explore colder environments and eventually become a new species, while the former species (less hairy) thrives quite happily in the warmer environment.  \n\nAnd the "half-evolved organ" argument is also silly ... e.g. half-a-wing with crappy feathers *is* useful even if the proto-bird can't yet fly ... if intermediate feathers keep it warm, and intermediate wings let it flap out of danger better (think of a chicken), then that's enough selective advantage that it will live longer and make more babies than its buddies with smaller wings or crappier feathers.  Intermediate stages can invariably be shown to be useful.\n\nThat's it.  It's a *really* simple idea.  Hope it's no longer Greek to you.
805180
Jonmc had it right, but I will try and restate it a little less beligerantly.  To put it in a single sentance, individuals don't evolve, segments of populations do.\n\nLet's say a short necked animal has two offspring.  One offspring has a long neck due to a random mutation in it's genes.  Now it can eat from the tops of trees, while the others still can only eat grass and bushes.  These two are NOT competing for the same resource.  When they have offspring of their own, these offspring will likewise not be competing with each other.  If the environment doesn't change, then in a few years you'll have one species of long necked animals walking around, and a species of short necks.  The long necks "came from" the short necks, but there is no reason the short necks should have died out or ceased to exist because of this.  \n\nOf course in real life, it's always much more complex than this.  Humans actually DID compete with the species that we came from, the earlier genuses of homo, and did replace them.  I hope this helps.
916499
I don't know why you asked the same exact question 3 times.  I gave a full description in another post.\nhttp://answers.yahoo.com/question/index;_ylt=AmiwcqFgnMC2QHEoVOkL3y_zy6IX?qid=20061127161951AALL9zd\n\n... But on the assumption that this is some school question or project, I'll try and compress all the evidence into just four main categories:\n\n1. Evolution reproduced in the lab or documented in nature, including the basic mechanisms of natural selection established in artificial selection (like breeding).\n\n2. Fossil evidence. \n\n3. Genetic and molecular (DNA) evidence.\n\n4. Common morphology and proteins (vestigial, homologous, and atavistic structures and proteins). \n\n5. Others (OK, that's 5 ... but I needed a place to include things like bacteriology, virology, imunology, embryology, biogeography).\n\nAgain, these are just the names of the *categories* of evidence ... for details, see my other post.
653816
Evolution is a theory.
482324
One of the arguments would be the lack of fossils for intermediate species. As there are many fish and reptiles fossils discovered, shouldn't there be at least some half fish-half reptile fossils as well?