Did Humans Evolve From Monkeys?

I’ll note that this is also being discussed on Jerry Coyne’s blog:
Dear BBC: Yes, we are descended from monkeys

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Jerry makes one simple mistake even in that piece. He thinks that a strict cladist would claim that we aren’t descended from monkeys, presumably because we’re descended from apes. But of course to a strict cladist (= just about any systematist, these days), apes are monkeys. Even many biologists have trouble understanding cladistic classification. I recommend a fine and readable introduction, Tree Thinking by Baum & Smith.

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So @John_Harshman thanks for this enlightening conversation. I’m thinking about this in a new way. I’m not some ways this reminds me of the exchanges with thomists, who have a platonic view of forms. In this case, it is similar but the ontogeny takes on a similar platonic normative force.

Here is my questions. How do you established directionality here? The claim is that apes evolve from monkeys. How do we know it wasn’t the other way around? Perhaps monkeys evolved from apes, right?

Related to this is the question of Pakicetus and whales. Sure, whales evolve from semi-aquatic land animals. However the type of land animal from which they evolve is simultaneously (1) very different than any land animals we see walking around now days, and (2) not remotely a whale yet. It is more like a carnivorous wolf-hippo, that starts to look like a mammalian-crocodile before becoming what we would recognize as a whale. Many call it a walking whale, as an oxymoronic indicator that it was something we currently don’t see among. So whales evolved from land mammals, but not a land mammals quite like what we see amongst us now. It is also not clear of the MRCA of extant whales would be recognizable as a whale, right? It might have been that wolf-hippo.

Any how, I appreciate your clarifications. I’m learning a lot.

Wrong. Apes are a clade within monkeys. Hence apes evolved from monkeys. Whatever characters you use to separate apes from monkeys are best optimized as innovations of apes. The alternative would be that different monkeys are convergent in those characters, which is not a parsimonious (or likely, if you prefer) alternative.

Depends on what you call a whale, i.e. whatever node you choose to attach that name to. Sure, Pakicetus looks like no modern animal. But how does that relate to the primate questions? As for the common ancestor of extant whales, you would clearly think it was a whale if you looked at it. It would have all the characteristics you associate with whales, because toothed and baleen whales share those characteristics by descent, not convergence. That ancestor wasn’t a wolf-hippo, but a much later animal.

The ancestral monkey wasn’t quite like any monkey we see now, but it had all the characteristics shared by extant monkeys. If a colobus and a spider monkey are both monkeys, so is their common ancestor. And so, given a monophyletic meaning of the term, are you.

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That is to my point and my question. What was said ancestral monkey like?

Here is one.

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One of the interesting things about science is that nature often works in ways that are not intuitive to humans (e.g. quantum mechanics). The natural history of species is one of those examples. We shouldn’t expect humans to intuitively group species in a way that accurately reflects their genealogical history. Therefore, there is often a disconnect between objective clades and subjective species groups described by colloquial terms in common human languages.

It would appear that humans intuitively look for paraphyletic groups for whatever reason, and our use of language reflects that trend. We probably shouldn’t force one term to conform to the other.

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This would take a reconstruction using a good data set and would involve mostly very technical features of bones and such. But I will hazard a start. It would be a short-faced, relatively flat-faced, binocular-visioned, long-tailed, arboreal frugivore, perhaps with a sex-linked polymorphism in one rhodopsin gene.

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Note that Aegyptopithecus is not an ancestral monkey; it’s an early catarrhine, postdating the divergence of catarrhines and platyrhines.

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Not surprisingly, this comment is so incredibly counter-intuitive that I have to ask about it. Let’s call quantum mechanics an outlier, because it is known for behaviors that really are completely counterintuitive. Let’s also leave out the natural history of species, because this is the topic being defined here.

When I, admittedly, so incredibly limited in scope as compared to the rest of the incredible minds here, think about what I know of science and what I observe in the world, I see logical, intuitive systems everywhere. Electricity is caused by electrons flowing from atom to atom in a predictable way. Fluid hydraulics are incredibly predictable and intuitive. Bodily systems such as respiration, circulation and nerves work in a systematic and predictable way. Chemistry is so predictable that one can calculate on paper alone just what will happen when two elements are mixed together. Physics is math applied to the universe such that we can understand what we cannot touch or even sometimes see (light, sound, motion.)

So, why, otherwise, would you say that science and nature behave in ways that are not intuitive? What other aspects are you thinking of? Others have made similar statements here as well. I thought to ask before, but didn’t.

As someone who teaches both introductory chemistry and physics to college science majors, things can be calculable and yet not-intuitive. When students are asked to draw a picture what happens when water boils, many (even chemistry graduate students) will draw H-O bonds breaking, which is so incredibly wrong chemically – even though they can do lots of complicated chemical calculations. Talk to students about projectile motion or gravity in a physics class (what I was doing today) an you will get some very “intuitive” but very wrong answers. Often sciences aren’t intuitive initially and it’s only after some time that things get better. Physics professors, in particular, spend a decent amount of time trying to break down misconceptions before building up a physical intuition.

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@Michael_Callen he is right. Science at almost every level is among the most counter-intuitive thing I’ve ever engaged.

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Thanks Jordan. Those are good examples. I remember being in physics class and our professor, suspecting many of us were not listening, said that gravity did not affect very small things–like flies, and that was why they could walk on the ceiling. Those of us who were listening, perked up immediately. Because if you swat a fly, and kill it, if falls to the ground. There are certainly some issues that are not intuitive at the outset (as with your examples), but it seems to me that most are systematic and intuitive. I was a very poor college student (and one for a very short time), yet I can figure out a multitude of complex systems in many different environments because they are typically systematic. This seems to be the case, intuitively.

Possibly you broke it! :rofl:

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Systematic and intuitive seem almost unrelated. Quantum mechanics is highly systematic and not at all intuitive, for example.

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100% agreed, Steve. In the original comment, long since sliced into pieces, I had called quantum mechanics an outlier because it is so counter-intuitive. Instead, I was asking about the other sciences. Please, though, what is the meaning of your moniker? I’m guessing there’s a story there?

Isnt there also the category: Great Apes among Primates?

There are a bunch of categories. We are great apes too, as well as apes and monkeys. Humans are within great apes within apes within monkeys within primates. All these categories have scientific names, considered as clades, but I see no reason to introduce those names.

You may have to keep in mind that many things seem intuitive because you have learned about them. I know it is impossible to forget everything you have learned, but try to imagine what it would have been like for scientists in the 1600’s or 1700’s. Take chemistry as an example. If they added ingredients in a different order they would often get different products. Why? If the space around us is filled with matter then why can’t we see it? Why is it only heat that flows through a system and not cold?

If you are interested in the history of science you might want to dig into the fight between the Rationalists and the Empiricists. The Rationalists contended that we could figure out how nature worked by thinking about it. The Empiricists contended that we had to verify our ideas through sense experimence (i.e. empirical evidence). As you can probably guess, the Empiricists won out. The reason we have the scientific method is because human intuition is faulty. We have found that the best (or better yet, the most pragmatic) models are those that we check against the measurable reality around us.

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Thanks, this is a great response. I see what you are saying and I think I’m guilty of conflating “intuition” that stems from modern discovery and “intuition” itself. I realize now that I’m basing my opinion that things are “intuitive” on a foundation of discovery regarding what is and what isn’t a “system.” Truly, there are many systems in play. We recognize them because of the empirical evidence that has been gathered. But, you are correct, there are many things that are not intuitive apart from this evidence. If I touched a piece of copper and it shocked me, it would not be intuitive that it were caused by flowing electrons. I might think that it contained an evil spirit or something of the sort.

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