AGS Steam Games

Forums → WEPR → Evolution

779 182527
stormwolf722
offline
stormwolf722
227 posts
Nomad

Well a lot of people have been telling me evolution is real. They give me the most craziest surreal 'facts'. Has anyone discovered any fish with legs? Any humans with gills or fins? If you put all the pieces of a watch into you're pocket and shake it around for trillions of years, will it ever become a watch? Is there but one possibility? Or if you completely dismantle a chicken and a fish, and put it into a box, shaking it around for trillions of years. Will it ever become a fish with wings? or a chicken with fins? :l

  • 779 Replies
Moegreche
offline
Moegreche
3,826 posts
Duke

The answer- there are no missing links. It simply doesn't exist.


Kasic is absolutely right. Absence of evidence is not evidence of absence. Especially when you look at the areas where our early ancestors lives, the conditions just weren't right for fossils to form.
But the fact that we so much evidence in favor of evolution by natural selection should put to rest doubts about missing links. As long as there are species out there whose fossils we haven't recovered, there will always be missing links. But this is not a sleight against evolution or even against our ability to find said fossils. It's merely an artifact of how biological organisms form, die, and become fossils (or don't).
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

There are some missing links in evolution. Darwin predicted that as more fossils were found, they would find the missing links. Today so many fossils have been found, and there are still so many missing links. The answer- there are no missing links. It simply doesn't exist.


When it comes to our direct ancestral linage as primates I would agree there really aren't missing links. In fact we have so many examples there is debate on whether some of them classify as a new species or are just a slightly modified step.

When we look at the entire tree of life we expect to find gaps. This is because the conditions for a fossil to form is very rare. So the amount we have found is comparable to looking for a needle in a hay stack and finding almost the entire sowing kit.

Another way to look art it is like a photo snap shot. You can find several photos of yourself at different stages of life, from an infant to the age you are now. In some points you will see drastic changes while other won't have that much. But because you may have gaps between those stages doesn't mean you weren't once that small infant int he photo.

The same can be applied to the fossil record we can find "snap shots" of the forms that once were and follow each &quothoto" in order to get an idea of where life was at each step along the way. Just because we might have a gap here and there is inconsequential.
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

Anyway my biology teacher told me that evolution was fact. Natural selection is a theory. And she has a degree in biology.


And your biology teacher would be correct. Evolution is both a fact and a theory.
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

Thank you! Everybody in my class dismissed the idea. They said it was because it contradicts religion. However, it does not because the holy books aren't meant to be interpreted literally. Therefore I think creationism is incorrect. Though symbolic interpretations of holy books isn't. Therefore they don't actually mean creationism, that's just a misintepretion of people taking things too literally...


From a non literal interpretation one could make this argument. Though if you are to consider parts of the Bible as real this leaves issues for later parts of it. If we are to consider it all to just be metaphors, this leaves it no better then a book of fables.
As for if it was meant to be taken literally or not, keep in mind the whole thing was taken literally for centuries until around the 18th century were scientific method began to prevail. So in some sense they are correct that it does contradict religion. Though to dismiss fact because it disagrees with your religion is simply closed minded and unthinking behavior.
HahiHa
offline
HahiHa
8,256 posts
Regent

Finding the common ancestor is hard because we know that we evolved, but how?

I think nicho posted this link a few pages ago, might interest you to read this:
Chimpanzee-human last common ancestor

But there can't be any fossils of a common ancestor, because the going theory isn't that we evolve over a long period of time but all of a sudden.

I'm really not a fan of saltatorism, I'm more inclined towards gradualism. And so is the general scientific opinion I think, although there are still debates.

However the problem is that they can't get fossils from land animals, only sea creatures as you need the water pressure and sedimentary rocks in order to mineralise the bones into fossils.

Um... uhuh... yeah... so all the tons of land animal fossils we found are all fake? Riiiiiiiight....

You know, tar pits, mud holes, volcano ashes, catastrophic events can indeed give the needed conditions for fossilisation, even if the process is easier underwater.

But that's the main reason why evolution is fact, yet natural selection is theory.

You don't even understand evolution correctly... evolution is a theory, which means it is the best explanation for all the evidence we found. Also natural selection is a part, a process of evolution, evolution wouldn't work without. I suggest you go over your books again, or buy new ones.
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

On another note, evolution of human beings didn't come from monkeys but rather from a common ancestor.


yeah actually we did come from monkeys. Just not modern monkeys. It can even be argued that we are still technically monkeys.
Turns out we DID come from monkeys!

But there can't be any fossils of a common ancestor, because the going theory isn't that we evolve over a long period of time but all of a sudden.


Where did you get that from? Yes we did evolve over a long period of time.


However the problem is that they can't get fossils from land animals, only sea creatures as you need the water pressure and sedimentary rocks in order to mineralise the bones into fossils.


We have plenty of fossils of land animals. Also the use of water isn't the only way something can become fossilized, it can also occur with the use of gases.

Therefore there isn't any for the common ancestor between human and the monkey's common ancestor.


Actually we do have fossils of our common ancestry with monkeys.
Here is an article demonstrating it's skull talking about the size of it's brain.
http://news.softpedia.com/news/Our-Ancestors-Dumber-Than-We-Thought-54694.shtml
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

They're both theories. Nobody really knows either way...


Theory doesn't mean that we don't know, it's an explanation of relation observations based on hypotheses and independently verified.

Evolution is a fact, not a theory.


Evolution is both a fact AND a theory.
Evolution: Fact and Theory
nichodemus
offline
nichodemus
14,991 posts
Grand Duke

A brain inside a skull is called a cranium. And yeah, there are common ancestors but not many. Did you know that there's also one of a hybrid between a reptile and a bird? That's how they think that the classes, birds and reptiles arose.


You clearly don't know Mage and his fearsome reputation and library-like knowledge on the subject. Carry on.
nichodemus
offline
nichodemus
14,991 posts
Grand Duke

You can go on to discuss the finer aspects of evolution. I'm staying out of this mostly, since my speciality isn't biology, and my college course will definitely not be science based.

HahiHa
offline
HahiHa
8,256 posts
Regent

Ok, so what you're saying is, there's no doubt that we did change from an ancestor, but the way how we changed is the theory part. Is that right?
But why only natural selection? It isn't the only mechanism of evolution; there's natural, sexual selection, mutation, migration, and genetic drift. Are you only mentioning natural selection because it is the least founded?

Some turned into monkeys, some in neanderthals, some into homo horribilus and some homo sapiens (us).

That's not what saltatorism is about, right? That's just different branches of the phylogenetic tree. They could have evolved in all those branches gradually. Gradualism and saltatorism is just about how fast it went. And, don't you think that maybe both are right? That mainly species evolve gradually, but certain high pressures can lead to a faster adaptation that we then perceive, through the incomplete fossil record, as saltatory?
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

yeah, but they are a different monkey, not a modern one. Then they evolved in different pathways to form both humans and modern monkeys. That evolution.


Yes that's what I said. You were the one who said we didn't evolve from monkeys. Now if you had said we didn't evolve from modern monkeys then you would be right. But I will guess that's what you actually meant.

That's the theory mainly talked about. That's called gradualism. However the lack of fossilised common ancestors makes for the theory of saltatorism.


When it comes to human evolution we have a rather complete fossil record. Since your going back to the monkey/human common ancestry and possibly earlier then we do start running into gaps.
It is actually possible that both rapid and gradual processes can happen dependent on the environmental pressures. We see an example of rapid evolution in the Italian wall lizard. Once transferred into a new environment it evolved an entirely new digestive system and behavior patterns.
Lizards Undergo Rapid Evolution After Introduction To A New Home

Did you know that there's also one of a hybrid between a reptile and a bird? That's how they think that the classes, birds and reptiles arose.


This get's a little sticky. If your talking about birds like what we have now then not exactly. We have the dinosaur in between reptiles and birds. However technically speaking dinosaurs are birds. So in that regard we can say there is a reptile/bird intermediate.
HahiHa
offline
HahiHa
8,256 posts
Regent

There's also adaptive radiation.

I'm not sure, but I think this is just a specific manifestation of the base mechanics.. the Darwin finks, right? Best example I think.

So phylogenetic trees are useful about pointing out where the species are supposed to have diverged, but without a fossilised common ancestor that is not proven. And it's not just humans that have common ancestors...

Of course it's not just humans.. and yes, phylogenetic trees are supposed to represent the pathway of apomorphies, leading to the current biodiversity. This way we can set up such trees without knowing the common ancestor; we just look at the different characteristics and which species have them or don't have them.

Only flying dinos like pterodactyls are both.

Gotcha! Pterodactyls aren't dinosaurs, but birds are descendants from small raptor dinosaurs.. flight in pterodactyls, birds, insects, mammals, developed independently.. there's a word for it that I forgot (the shame...).
HahiHa
offline
HahiHa
8,256 posts
Regent

Phylogenetic trees are also based on animals and similar physical similarities. If they have similar physical properties, then they are thought to have a common ancestor less long ago.

Yes, such trees generally look at various characteristics, physical mostly in paleontology, microscopic and others especially in contemporary biology. All descendants of one ancestor share an apomorhpy, a character unique to them that others don't share. Maybe that picture helps a bit those who didn't study this before:
http://upload.wikimedia.org/wikipedia/commons/e/e8/Synapomorphy.jpg

And pterodactyls are dinosaurs because they have scaly skin, not feathers. Therefore they are dinosaurs.

There were a whole bunch of animals with scaly skin, but not all of them were dinosaurs. Pterodactyls aren't classified as dinosauria, but as pterosauria; just as Plesiosaurs aren't dinosaurs, but plesiosauria. There's no arguing about that

Convergence! That's what I've been looking for! Flight is an analogous characteristic evolved in different lineages through convergent evolution.
MageGrayWolf
offline
MageGrayWolf
9,462 posts
Farmer

No, I saw a picture rendered according to the calculations of what the fossil dictated. It looked like a pelican with reptilian features.


What you likely saw was an transitional form from dinosaurs to the modern bird. Similar to archeopteryx or microraptor.
To put it simply

reptiles > dinosaurs > birds

though technically dinosaurs = birds

so we can technically say reptiles > birds

Though dinosaurs are classed as reptilia so this means

reptiles = dinosaurs

Given this we can expect to find reptilian features and avian features. As dinosaurs are a transitional point between.

The T-Rexes and the other dinos on land have just got reptilian features.


They also have avian features. We can see this in their bone structure and using T-Rex as an example they had proto-feathers in their early stages of life.

analagous properties. And pterodactyls are dinosaurs because they have scaly skin, not feathers. Therefore they are dinosaurs.


No they are not dinosaurs, in fact there are a number of dinosaurs with feathers. Pterodactyl was a flying reptile unrelated to the dinosauriformes.

Well, I don't know. The common ancestor could've been more human than animal. Like a slightly devolved and less intelligent neanderthal (because neanderthals aren't as stupid as people think, they're overhanging brow make them seem that way and they were less intelligent than us, but they weren't mentally retarded (or disabled if that's more politically correct...)). Or maybe it was more monkey than human or neanderthal or other homo. Therefore I don't really know what our common ancestor would've looked like because I wasn't there.


Yes we do have transitional forms and even direct common ancestors that are more human. In fact this list is extensive. These however are later additions. However we can follow this further back and find a common ancestor with monkeys and humans. The ancestor is something we have a fossil record of.
HahiHa
offline
HahiHa
8,256 posts
Regent

They may be of different phyla, but there still of the same class of species. That is reptile. Reptiles in the triassic period were generally dinosaurs. Ipsofacto, pterodactyls are dinos. U even seen jurassic parK???

This is becoming systematic nitpicking^^. It seems we agree on the systematic level, you simply use dinosaur as an absolutely not systematic term, while I do. And Hollywood movies are poor support for systematic questions -.- lol...

See? Told u they were analagous...(:

Thanks for the keyword^^

though technically dinosaurs = birds

Not quite. Aves are a subgroup of the dinosauria.

reptiles = dinosaurs

Gah... I'm too strict with systematics and popular names am I?
Showing 541-555 of 779