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I learned at school and in the documentaries like everybody that (to summarize) molluscs evolved into fishes then reptiles then mammals then humans.

Does the theory still make the same claim ? or does neo darwinism only defends speciation where for example all camelidae are related and all felidae are related, but both aren't related.

If not, why the famous evolution trees never identify any of the supposed common ancestors ?

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    $\begingroup$ I was going to point out the missed opportunity in not asking how the theory has evolved over time, but then thought better of it, since the theory has undergone nonrandom, directed alterations with a clear goal in mind - not an evolution-like process at all! $\endgroup$ – Nuclear Wang Mar 6 '18 at 17:37
  • $\begingroup$ If you want to see a modern tree of life I high recommend the Phylogenetic Tree of Life by by David Hillis, the you are here is a nice touch. zo.utexas.edu/faculty/antisense/tree.pdf $\endgroup$ – John Mar 7 '18 at 2:51
  • $\begingroup$ For a great description of evolution I highly recommend the Stated Clearly channel, specifically the "what is evolution" and "what is natural selection" videos. Per their motto the information is stated clearly and simply and I recommend it to my intro students all the time just becasue of that. statedclearly.com $\endgroup$ – John Mar 7 '18 at 3:06
  • $\begingroup$ @John statedclearly.com is really bad... it uses the red stamp FACT as a coercive manner to convince the viewer; it claims that evolution is only changes with generations but later it states that all species are related; it uses HIV as an example while it has been known for decades that it's not related to diseases $\endgroup$ – WaterBearer Mar 7 '18 at 15:30
  • $\begingroup$ I agree the stamp thing is a bit much as the word fact is not a scientific term but everything else you list is actually true, this is one of the reason we keep recommending you learn a bit about evolution, all species are related, evolution does occur across generations, the former is a direct result of the latter, the difference between one species and another is just a sequence of generations. Its like saying humans walk by taking one step at a time and you can walk from New York to San Francisco, if you take enough individual steps. $\endgroup$ – John Mar 7 '18 at 16:23
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How has the theory of evolution changed over time?

It improved quite a bit. To put things in perspective; today most of evolutionary biology is about evolutionary genetics while at Darwin time (On the Origin Of Species was published in 1859), we really had no idea about DNA (the basic structure of DNA was only discovered in the 1950s).

A number of the original claims were found to be wrong though (or off-topic). We've added much more than we've removed though!

I learned at school and in the documentaries like everybody that (to summarize) molluscs evolved into fishes then reptiles then mammals then humans. Does the theory still make the same claim ?

This claim is not correct (and has never been) or at least is very misleading. I hope your teacher did not really tell you that!

or does neo darwinism only defends speciation where for example all camelidae are related and all felidae are related, but both aren't related

Nope, this would be even more wrong!

Among all extant species today, none are ancestors of others. They all share a common ancestor though. The common ancestor between a lynx and cat lived more recently than the common ancestor between a lynx and an oak tree.

Also, the claim put an emphasis on humans, which sounds like you viewing some kind of goal to evolution or eventually some kind of 'improvement' where humans would be the best or something like that. That notion of good or better is not just wrong, it is off-topic in any scientific discussion.

Some of the clades you mention contain other mentioned clade (for example, humans are mammals), however 1) fish is not a clade (not monophyletic, see this post for an intro to phylogeny) 2) ancestors of mammals have never been mollusc 3) note that the term reptile you use can take two different definitions; a popular meaning and a rigorous scientific meaning (which we use called Reptilia) (have a look at the post If dinosaurs could have feathers, would they still be reptiles?). In any case, no ancestors of mammals were reptiles (although mammals are Reptiliomorphia).

If not, why the famous evolution trees never identify any of the supposed common ancestors ?

I don't really understand this question.

We are able to date pretty well the common ancestors of most lineage of interest through molecular tools. We have a lot of fossil records which, when dated, match our finding with molecular tools. Note that the one most recent common ancestor between two lineages is a single individual (although recombination makes this point more complicated but I won't talk about that here). Of course, we probably never have a fossil of this single individual, but we often have fossils of individuals that are quite closely related to this individual.


You seem to have an extremely biased view of the theory of evolution. I am sorry if your teacher taught you so wrong. The best for you is to simply start with an intro course such as Evo101 for example. Evo101 is short, very introductory and easy to read.

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    $\begingroup$ There's also a problem with "famous evolution trees", in that we don't know what the OP considers "famous". Lots do show common ancestors, though it's hard to show millions of species on a piece of paper. Here's one site (of many) that attempts to do it: onezoom.org And another: sciencemag.org/sites/default/files/styles/article_main_large/… $\endgroup$ – jamesqf Mar 6 '18 at 19:22
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    $\begingroup$ On the Origin of Species contains several large sections which have been removed from our present understanding of evolution. For instance Darwin's lengthy description of the societal roles of men and women in 19th century Britain would no longer be considered to be a usable (or good, or necessary) argument. $\endgroup$ – tsttst Mar 7 '18 at 1:50
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    $\begingroup$ @tsttst Good point! I replaced "Only few" by "A number" to make it softer the claim that not much has been removed. $\endgroup$ – Remi.b Mar 7 '18 at 1:53
  • $\begingroup$ examples of things added to the synthesis includes: all of genetics and heredity (darwin had no idea how heredity happened but it was painfully obvious it occured), discovery of the mathematical underpinnings of evolution, the mechanics of selection, etc. $\endgroup$ – John Mar 7 '18 at 3:00
  • $\begingroup$ @Remi.b I live in France and I took science at high school, evolution must only have covered a couple pages in our book and the teacher only spoke of it for 15 minutes, so most of what I was taught came from the general culture - we did however study genetics. What do you think of youtu.be/lIEoO5KdPvg?t=9m35s is it biased as well ? $\endgroup$ – WaterBearer Mar 7 '18 at 15:35

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