Help an atheist understand evolution better please

Sapient
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Help an atheist understand evolution better please

Hey folks... this is an easy one, I'd address it, but I'm short on time (moving day), so maybe some of you can take it and I'll direct him here. This was sent to the Rational Response Squad mailbox:

Quote:
Message: First, let me say that I consider myself an Athiest and I do buy into the theory of Evolution. However, here is a question I cannot answer and I was looking for help.

Part of Evolution is/was the process of how we humans came to exist. Our
ancestors are said to have been primates. Now let me see if I can word this question clearly.

Why is there a gap, in known species, between primate and human? If Evolution is a process, shouldn\t some sort of apish human currently exist in the world?

An animal that hasn't quite progressed fully?

These questions make me think that Evolution has stopped occuring, thus posing the question that it even existed in the first place. And that bothers me.
Although I see more holes in Creationism, I do consider this a whole in our believed theory and was hoping you could help me out.

Thank you for your time.

- Brian Sapient


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LeftofLarry
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Help an atheist understand evolution better please

ok..I'll tackle this one.

First off, you have to understand that evolution is a very sloooooooow process.

There is no gap. We just haven't discovered all the steps yet..but every day we find new evidence..one step closer. This takes research and sceince. We did not evolve from primates. We are part of a gropu of primates that have evolved from a commone ancestor. It's much like this, take all the different familes of snakes out there. You have colubrids (rat snakes, corn snakes, bull snakes etc..) viperids (vipers, copperheads, cottonmouths, boids (boas and pythons), elapids (cobras, coral snakes) etc.. all the snakes look alike right? but they are all unique some more evolved (colubrids, viperids) and some less evolved (boids, they still have vestigial legs calles "spurs"Eye-wink but they have all evolved from a common ancestor. Now the same goes with primates, you have gorillas, chimps, humans etc....

Secondly, keep in mind that when humans evolved, other human-like species (Homo neanderthalensis) were also evolving..at the same time, they just happened to die off because of natural selection. WE have evidence of this. And that, some say, is the evidence. WE do have a gap between homo neanderthalensis and homo erectus, say 500 thousand years...but we are certain based on former evidence that our species was evolving from even older species homo ergaster and homo habillis...etc.. so it is obvious that the lineage is connected, we just have to find it. Smiling Also, keep in mind that evolution is constantly occuring, we are seeing this with for example, immunity to disease in people. There are people that live in Africa that are immune to certain strains of malaria, based on teh fact that their genome has changed to not produce the protein that malaria recognizes to infect their red blood cells. So evolution has not stopped, not even in humans...immunology is one of the best examples to support this. Anyone else..please add to this short post.

go here for the evidence...and you'll see.
http://www.becominghuman.org/

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PipetPersonJ
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Help an atheist understand evolution better please

The only thing that I would add to what Larry said is that if you've ever seen a model of what Australopithecus afarensis (Lucy) is supposed to look like, it's essentially a really hairy midget (3'8"Eye-wink with a very ape like skull. Just seeing the skeletons of these things doesn't give you much to work with, but given skin and a little fur you can actually very easily see the blending of great ape and human.

A link for more info: http://en.wikipedia.org/wiki/Australopithecus_afarensis


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Help an atheist understand evolution better please

One response I had read about the "gap" criticism was like this. Say there is a "species 2" that evolved from "species 1." The anti-evolutionists will complain about the gap. Well, say scientists discover "species 1.5", the link between the 2 species. Well, now they will claim there are 2 gaps! They will point out a gap between "species 1" and "species 1.5", and another one between "species 1.5" and "species 2." So nothing will ever be good enough for them, and you get the old "god of the gaps" again. :roll:

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Help an atheist understand evolution better please

MattShizzle wrote:
One response I had read about the "gap" criticism was like this. Say there is a "species 2" that evolved from "species 1." The anti-evolutionists will complain about the gap. Well, say scientists discover "species 1.5", the link between the 2 species. Well, now they will claim there are 2 gaps! They will point out a gap between "species 1" and "species 1.5", and another one between "species 1.5" and "species 2." So nothing will ever be good enough for them, and you get the old "god of the gaps" again. :roll:

THat is their way of refuting the obvious. I don't see them, however, out there researching. POint is this, if they don't believe in anything scientific, they most theists need to stop taking medication, then, we'll see how the process of natural selection really works.

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Help an atheist understand evolution better please

PipetPersonJ wrote:
The only thing that I would add to what Larry said is that if you've ever seen a model of what Australopithecus afarensis (Lucy) is supposed to look like, it's essentially a really hairy midget (3'8"Eye-wink with a very ape like skull. Just seeing the skeletons of these things doesn't give you much to work with, but given skin and a little fur you can actually very easily see the blending of great ape and human.

A link for more info: http://en.wikipedia.org/wiki/Australopithecus_afarensis

Absolutely, some say Lucy was indeed the missing link.

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Klarky
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Help an atheist understand evolution better please

Here's is a useful way of thinking about gradual evolution and speciation.

Imagine an extremely long roll of paper. One end represents the common ancestor of humans and the other end represents Homo sapiens, (modern humans).
Now take some blue and a red paint. (Blue representing the Ancestor and Red representing Homo sapiens).
Start with the blue paint at the ancestors end and paint a line towards the Homo sapiens end, but as you paint start to slowly change the colour from blue to red, until you reach full red at the Homo sapiens end.
Now go back and try and find the point where blue became red? You can't do it!

This analogy can be used for the whole of life. Although of course one would need lots of rolls of paper that overlaps in places and that branch out.. heh Sticking out tongue
If one knew the future, one could plot Humans as the ancestor and whatever we evolve into at the other end ! :shock:
It's also worth pointing out that species are a human categorisation thing. Although species can represent a distinction genetically, in reality nature knows no such boundaries. I often bring this up when creationists talk about "kinds" with their awkward description of what a "kind" is!


MattShizzle
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Help an atheist understand evolution better please

That is a good analogy!


Lucretius
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Help an atheist understand evolution better please

i'll play the part of a walking advertisement:

Zachary Moore has a podcast called Evolution 101 which you can find on iTunes, and it gives a nice overview of evolution.

I have my own podcast called "The Big Bang and Creationism" where I talk science (not just evolution though) and refute various Creationist/Intelligent Design claims.

Talk.origins of course is an excellent site to reture Creaitonist arguments.

The University of Berkeley also has a website on evolution.


Atheist_Scathe
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Re: Help an atheist understand evolution better please

Sapient wrote:
Hey folks... this is an easy one, I'd address it, but I'm short on time (moving day), so maybe some of you can take it and I'll direct him here. This was sent to the Rational Response Squad mailbox:

Quote:
Message: First, let me say that I consider myself an Athiest and I do buy into the theory of Evolution. However, here is a question I cannot answer and I was looking for help.

Part of Evolution is/was the process of how we humans came to exist. Our
ancestors are said to have been primates. Now let me see if I can word this question clearly.

Why is there a gap, in known species, between primate and human? If Evolution is a process, shouldn\t some sort of apish human currently exist in the world?

An animal that hasn't quite progressed fully?

These questions make me think that Evolution has stopped occuring, thus posing the question that it even existed in the first place. And that bothers me.
Although I see more holes in Creationism, I do consider this a whole in our believed theory and was hoping you could help me out.

Thank you for your time.

Sapient, my short answer to this is divergence. There are no "apish humans" (hmm... wait a minute... our "president"?! :twisted: ) to our knowledge because after our divergence with what would become the genus Pan or chimpanzees, the two stocks drifted in different directions. Now, in all fairness, the "us" stock (to give it its proper name, the hominini or hominins), DID diverge further: afarensis gave rise to africanus as well as to garhi; garhi to Homo habilis and rudolfensis but africanus to aethiopicus and hence to boisei in eastern Africa and robustus in southern Africa. These "Robust" australopithecines seem to have flourished for a time across much of southern and eastern Africa, only to disappear most likely due to climate change (this was during the period of the Ice Ages) and/or competition with other lifeforms: vegetarians, they may have lost out to forest antelope and great apes such as chimpanzees and gorillas (ironic, huh?).

H. habilis flourished for some time, but then began to change by about 1.8 million years ago. Startling finds from Dmanisi, Georgia, reveal a creature clearly affiliated with habilis but with modifications reminiscent of the later H. erectus. At the same time in Africa our ancestor, H. ergaster, was evolving from habilis. Both of these two quite similar species flourished side-by-side for hundreds of thousands of years, perhaps a million, employing rather similar technology (the famous bifaced Acheulean hand-axes) and possessed of fairly equivalent capacities. The differences between the two were mostly cranial: ergaster possessed a higher cranial vault and a skull that bulged at a higher point than erectus. H. ergaster lived mostly in Africa, H. erectus mostly in Eurasia.

By about 800,000 years a change seems to have taken place: an exodus of ergaster from Africa, pushing into the Middle East, parts of central Asia and Europe. Ergaster populations in the circum-Mediterranean lands by about 500,000 years ago seem to have split off from the southern populations that would someday give rise to modern humans, producing a distinct form known as Homo heidelbergensis. H. heidelbergensis in turn gave rise to the famous Neandertals (minus the "h" in many circles), H. neanderthalensis (yes, the "h" is in the scientific name), while to the south other ergaster became Homo sapiens and eventually, Homo sapiens sapiens. Due to greater mastery of the tools of culture, language and social organization, modern humans drove the Neandertals of western Asia and Europe to extinction by about 28,000 years ago (the date of the most recent Neandertal finds from Spain and Croatia) and the remaining erectus populations of southeast Asia to the same fate by about 27-25,000 years ago. The tiny erectus derivative Homo floresiensis held out longest on the Indonesian island of Flores, but it too is believed to have gone extinct, due to a disastrous volcanic eruption 12,000 years ago.

So to sum up: we lack such a creature (unless, perhaps, the legends of Bigfoot, Yeti, and the Orang Pendek pan out) due to evolutionary divergence and the forces of competition and change.


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Help an atheist understand evolution better please

here are some visual aids for macroevolution :

FEEL FREE TO USE THIS ON FORUMS


lunkradio_dot_com
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Help an atheist understand evolution better please

that middle one is horses - forgot to label


Atheist_Scathe
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Help an atheist understand evolution better please

lunkradio_dot_com wrote:
here are some visual aids for macroevolution :

FEEL FREE TO USE THIS ON FORUMS

Hey great, thanks for these! Like to point out, though, that the one graphic of human/putative human ancestors is a bit dated- actually I think most theorists would agree that Australopithecus africanus was the founding species for the Paranthropus taxon, formerly called "Robust australopithecines" and placed in the Australopithecus genus- P. aethiopicus, P. boisei and P. robustus; our Homo genus is thought to have sprung independently (perhaps by way of Au. garhi) from Au. afarensis, which also gave rise to Au. africanus.