71–80 of 142 posts
>The reason for this likely elevated status is because we can now say that anamensis and afarensis actually overlapped in time. This seems to be the rule, rather than the other exception, at least in human evolution. Erectus overlapped with more modern archaics, for example. Habilis overlapped with afarensis. A lot of these are more about the semantics than the substance. Words like "species" get tricky, when you're…
Earlier quoted context omitted.
'Closeness' (whatever you mean by that) doesn't really imply ancestry without some hefty presuppositions.
> 'Closeness' (whatever you mean by that) doesn't really imply ancestry without some hefty presuppositions Of course it does. It doesn't prove ancestry. But genetic similarity implies proximate shared ancestry. We can take microbes (or fruit flies), subject them to stress, let the survivors reproduce, and watch the genotypes branch into a diverse population. We can then take the observed path of genetic variation and…
...And science isn't really about proof, it's about predictive models that are falsifiable but which have resisted falsification. While it hopes to reach or approximate truth, ultimately it's about pragmatic utility.
>The reason for this likely elevated status is because we can now say that anamensis and afarensis actually overlapped in time. This seems to be the rule, rather than the other exception, at least in human evolution. Erectus overlapped with more modern archaics, for example. Habilis overlapped with afarensis. A lot of these are more about the semantics than the substance. Words like "species" get tricky, when you're…
"You could fit it all into the back of a pickup truck if you didn't mind how much you jumbled everything up." - Ian Tattersall
https://www.goodreads.com/quotes/6578939-since-the-dawn-of-t...
It also seems like every time they find a new fossil, they change their mind about how everything fits together. I am not an expert in this field, but if I had a small dataset and I fit a very complex model to it with literally hundreds of free parameters and I found that the model completely changed every time I added a few new data points and re-fit, then I would conclude I was dealing with a high-variance model that was overfitting the data and either use a simpler model or wait until I had collected much more data before trying to fit such a complex model.
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> A fossil hominin cranium was discovered in mid-Pliocene deltaic strata in the Godaya Valley of the northwestern Woranso-Mille study area in Ethiopia. Here we show that analyses of chemically correlated volcanic layers and the palaeomagnetic stratigraphy, combined with Bayesian modelling of dated tuffs, yield an age range of 3.804 ± 0.013 to 3.777 ± 0.014 million years old (mean ± 1σ) for the deltaic strata and the…
ELI5
The impression I got from a recent PBS Eons video on the non-existing missing link[0] is that interbreeding happened all the time and that a very realistic possibility for the answer is "most, possibly all of them" . [0] https://www.youtube.com/watch?v=pwW40Dj5Sro
Regarding the multiple human ancestors aspect, here is an diagram of human species or groups if you want to avoid the "what is a species discussion" : https://imgur.com/a/AfrYjqF It is from a recent symposium [1] on human evolution The vertical axis is the age. The horizontal axis represent the geographical spread and the color represents the continent. We can see multiples things: - Disregard the 2010, it is indeed…
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Are you implying that if we don't know all the details of something, then we just don't know it? That is, are you implying that if we don't know all the details about our evolution, then we should just say that we know nothing and ignore all the things we actually do know are very very likely? That would leave you without any empirical sciences, because there has always something we do not know. When Newtonian mechan…
> if we don't know all the details about our evolution, then we should just say that we know nothing and ignore all the things we actually do know are very very likely? Nothing wrong with studying and figuring out how things work, you should not look at it with an all or nothing attitude. But assuming from the very start that all human species ancestors are some kind of ape is just so ridiculous that it can only sink…
No one makes that assumption. We know from copious hard evidence that humans and modern apes are closely related, and from more limited hard evidence that there were other animals with features similar to both humans and apes long ago. More recent human ancestors were not apes (they were more human-like), and way distant past ancestors were not apes (they were before even prehistoric apes existed), and none of our ancestors were modern apes (which have evolved into their modern forms since our last common ancestors with them, and those common ancestors were not apes as we know them today). Some human ancestors were prehistoric ape-like animals.
Teaching well-established scientific knowledge in schools is essential, and about as far from criminal as it's possible to get. Your "all human species ancestors are some kind of ape" is not well-established scientific knowledge, but your faulty assumption of how you imagine others' knowledge to work.
You seem to be starting with the assumption that evolution isn't real (based on a primary school reaction?!), rather than deriving the knowledge that it is real from the evidence. (Yes, I have actually done this. I had a summer job deriving evolutionary relationships directly from genetic data. It's not difficult, and the connections between species just pop out of the DNA sequences with a bit of maths.) Evolution wasn't just made up, it was figured out from the evidence, just like gravity, electricity, chemistry, etc. Like all scientific fields, our knowledge of it is not complete (and never will be).
Earlier quoted context omitted.
> A fossil hominin cranium was discovered in mid-Pliocene deltaic strata in the Godaya Valley of the northwestern Woranso-Mille study area in Ethiopia. Here we show that analyses of chemically correlated volcanic layers and the palaeomagnetic stratigraphy, combined with Bayesian modelling of dated tuffs, yield an age range of 3.804 ± 0.013 to 3.777 ± 0.014 million years old (mean ± 1σ) for the deltaic strata and the…
ELI5
I wonder if it is possible to extract some DNA from the artifact and use it for cloning?
>The reason for this likely elevated status is because we can now say that anamensis and afarensis actually overlapped in time. This seems to be the rule, rather than the other exception, at least in human evolution. Erectus overlapped with more modern archaics, for example. Habilis overlapped with afarensis. A lot of these are more about the semantics than the substance. Words like "species" get tricky, when you're…
My impression is that we just don't have enough data to draw an accurate timeline, much less a tree, and are an order of magnitude away from being able to study second-order phenomenon like introgression. I think fewer than 10,000 early hominid individuals have been found, most with very partial skeletons. And they aren't distributed uniformly across time and space; you might find a dozen in one cave, then nothing fo…