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iSilurian

Transitional Fossils

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44 minutes ago, hasanhh said:

Not since school l got that info a few years ago from a TV program and then used that as a lead to look this up on-line.

What do you think about my Daynes prejudiciality comment?

Hm. In regards to your Daynes comment, im sort of indifferent to how artists depict things like emotion. Im more interested in the bones than if the being had a nice smile or not.

"The prejudicial pre-conception that hominids must look ape like."

For this, i would ask, what would you think early hominids look like, if not partially or somewhat ape like?

 

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51 minutes ago, iCambrian said:

Hm. In regards to your Daynes comment, im sort of indifferent to ...

"The prejudicial pre-conception that hominids must look ape like."

For this, i would ask, what would you think early hominids look like, if not partially or somewhat ape like?

 

Kinda "moon faced" like the skull fragments show.

But here is a suggestive question: since, allegedly, the fossil record shows "our evolutionary linage" to be traceable to lemur-like, then why didn't pre-man have snouts? 

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1 hour ago, hasanhh said:

Kinda "moon faced" like the skull fragments show.

But here is a suggestive question: since, allegedly, the fossil record shows "our evolutionary linage" to be traceable to lemur-like, then why didn't pre-man have snouts? 

Not sure if youre asking a question related to fossils and morphology (a quantitative kind of thing morphology vs time), or if your question is more a question of "why" people do not have snouts, or a sort of theoretical question (why did mankind lose the long nose?).

Regarding sahelanthropus, the skull does appear to have a slightly elongated snout, and those who have published on it, claim the same.

But, regardless of what I or anyone else might think about sahelanthropus, "lemur like" to me, implies that you're referring to something like Ida.  But Ida has been dated at, according to a quick google search, 47 million years old. Im not familiar with the leanage between fossils like Ida (47 million years ago), and fossils like Sahelanthropus (6-7 million years ago). So, for all I know, the use of a snout and its morphological presence, may have been predominantly lost by the time pre historic mankind (sahelanthropus) appeared (im about certain this is what would be found if looking into the topic). So the snout would have been predominantly lost, in a "gradual" sense, between 47 mya to 6 mya.

Doing a quick google search now. 

https://en.wikipedia.org/wiki/Human_evolution#Early_evolution_of_primates

Of the fossils listed in the early evolution of primates (pre sahelanthropus), there are a number of primate skeletons that appear to have more "snout" length than sahelanthropus, but less than something like Ida (these fossils are post Ida)..

So pre man between Ida (that has a snout) and sahelanthropus (a bit more than we do but not much of a snout compared to Ida) may have had a relatively longer snout than sahelanthropus (see " Proconsul, Rangwapithecus, Dendropithecus, Limnopithecus, Nacholapithecus, Equatorius, Nyanzapithecus, Afropithecus, Heliopithecus, and Kenyapithecus, all from East Africa. ").  Pre man after sahelanthropus may have had a relatively shorter snout to the point of no snout.

So quantitatively, thats how I would answer.

If the question was more..."abstract"...why our ancestors lost our long noses? I dont know. Regarding our feet, it makes sense to me that when we began walking upright, we were walking on ground, and therefore didnt need long toes to grab branches anymore.  The loss of our long noses also may have just been a product of us not needing them.  Our vision became better, as far as im aware, the current idea is that we gained color vision in post Ida times (theres actually a cool video on youtube about gene therapy and giving lemurs colored vision).  Perhaps color vision took priority in what was significant in our lives (like finding bright colorful fruit that cannot be smelled), over the use of our noses. Whereas back in Ida times, use of our nose may have taken priority over non colored or blurred vision.

But, i dont study primates or primate evolution, so these are just ideas. Morphologically, we can see things with some clarity.  Why features develop, is always hypothetical. We can only guess at why a feature became beneficial or was "selected" back in those times.

Edited by iCambrian

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@iCambrian  Your use of "loss of nose" for loss-of-snout is a physical non sequitor.

Some of the listed primates in the article provided have snout-like protrusions, some ape like and some without -like modern humans.

This shows why l am skeptical of most evolutionary models: too much speculating. As you wrote, "The loss of our long noses may also just been a product of us not needing them."  Then why do we still have them?

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39 minutes ago, hasanhh said:

@iCambrian  Your use of "loss of nose" for loss-of-snout is a physical non sequitor.

Some of the listed primates in the article provided have snout-like protrusions, some ape like and some without -like modern humans.

This shows why l am skeptical of most evolutionary models: too much speculating. As you wrote, "The loss of our long noses may also just been a product of us not needing them."  Then why do we still have them?

I took the question as one about the length of our nose, not as a question of if we still have one or not.

Presumably we still have our nose because we use it. Though we arent dependent upon it like say, a mouse, hence the lack of protrusion and our lack of enhanced smelling senses in comparison to other animals (our ability to smell isnt particularly good). Smelling not being of a critical need for our survival, turns to its gradual disappearance.

Either way, its nice to ponder these questions. Like you said, there is certainly a lot of speculation involved with why things changed through time into the way that they did.  You bringing up the marsupials and dogs is interesting, because we could ask why they ended up taking a similar form or looking similar. Same with some antelopes and deer. Why would convergent evolution occur between any two species?

Something, certainly does appear to guide why we turn out the way we do. And our environment does appear to play a role.  Are our morphological changes limited to those driven by the environment?

A series of "random walks" comes to mind, where morphological changes in species trend in different directions at different times. The word "Random" only being used because we really dont know what was driving or turning that direction of the particular species.  All good questions and thoughts.

Edited by iCambrian

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