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Comment by vfc1 | Hacker News Reader

Why does it have to be only one ancestor ape, and not several that evolved human-like features simultaneously in the same environment?

We have Neanderthal DNA, that we inherited through interbreeding.

Why can't both we and the Neanderthals be descendent from a varied group of very similar apes that interbred as well? Isn't this the most likely scenario?

Sometimes I think scientists fall for the same simplistic patterns of thinking that the men on the street fall for every day.

Like, there is only one solution, there is only one cause, there is only one reason, when in fact reality is much more complex than that.

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> Sometimes I think scientists fall for the same simplistic patterns of thinking that the men on the street fall for every day.

Sometimes I think that BBC articles don't do a perfect job of precisely explaining the patterns of thinking of scientists.

> Why does it have to be only one ancestor ape

It doesn’t. That is the crux of this article and almost all the scholarship I’ve encountered on the question over the past few decades.

> Isn't this the most likely scenario?

No. The human genome is unusually homogenous, in part thanks to recent Ice Ages inducing bottlenecks. The simplest explanation, to our proximate evolution, is linear. (The simplest explanation is wrong.)

The fossil evidence, for that matter, while it shows significant overlap, does, broadly, present a remarkably-linear path over about 4 million years, with a series of branching-then-consolidating phases.

>Sometimes I think scientists fall for the same simplistic patterns of thinking that the men on the street fall for every day.

Practising scientists are loath to speculate without good evidence; it lays them open to criticism by peers, and damages their credibility with reviewers. Unfortunately this means that there is often a lot of inertia that slows the change of focus and means that there is some waste as the wrong work gets done (work that is known to be irrelevant by most of the community, but passes review). On the other hand this reticence does mean that there is less flailing around and hype than you see in other areas - such as business IT fads (Big Data, ML, AI, Serverless, Microservices...)

>Sometimes I think scientists fall for the same simplistic patterns of thinking that the men on the street fall for every day.

From the article:

>The term "missing link" drives anthropologists crazy when they hear anyone, especially journalists, use it to describe a fossil that is part-ape and part-human.

>Indeed Dr Henry Gee, a senior editor at Nature, once threatened to "rip my liver out and eat it with onions, borlotti beans and a glass of claret" if I did so when reporting a previous discovery.

>There are many reasons for Henry's irritation, but chief among them is the recognition that there are many links in the chain of human evolution and most if not nearly all of them are still missing.

This is your own painting with a massive brush. Obviously people who devote a lot of their lives to figuring this stuff out know there is not one solution. It's important to at least create a hierarchy of species that we've evolved from and something will inevitably be closest to our genetic makeup.

> a varied group of very similar apes that interbred

Such a group would simply be one species. Having many different species as ancestors also wouldn't explain the exceptional homogeneity of the human genome.

The present discovery though doesn't change things as much as the article tries to imply. It just means the speciation (from the appearance of A. afarensis to the disappearance of A. anamensis) lasted longer than previously thought, or at least that the A. afarensis species appeared earlier than we thought.

All the rest is complete speculation and the discovery doesn't really give any reason to think our ancestry tree might be different than previously thought.

Is it a metaphor problem? That in the language there's still an underlying assumption of a tree-like shape, where a trunk diversifies into many little branches... but of course if you look at an individual and trace backwards, the further you get, the more ancestors you have.

Yeah, it's a blegg/rube error. The lines between species are a lot blurrier than our nice neat taxonomy would have you believe.

> Why does it have to be only one ancestor ape, and not several that evolved human-like features simultaneously in the same environment?

They have first to geographically split to live and evolve in two separate similar environments and then merge while still being compatible.

HN is such an amazing community. Where else could you find commenters that know better than the scientists authoring the Nature article in question, and can then identify exactly why their own thinking is so much deeper than of most other people?

> Where else could you find commenters that know better than the scientists authoring the Nature article in question,

They don't know better, they try to understand better. Why not?

When someone talks about how "scientists fall for the same simplistic patterns of thinking that the men on the street fall for every day", while explaining how "in fact reality is much more complex than that", does it feel like they're humbly trying to better understand the world?

To me it sounds like someone who clearly has a deeper understanding of the topic than those scientists. And I love that.

Does the comment strike you as "understanding" or even "trying to understand"?

It paints a blanket picture, with no qualifications (read a few articles at best), and belittles what the scientists in general "do".

Also the point the commenter thinks they're original in making is the main point of the actual article.

Every online newspaper's comment section?

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