Originally posted by Krypton
I said dog-like mammal. We have been able to manipulate dogs, but we have not been able to create an animal we wouldn't consider a dog. I don't care how long of time they have, a dog will always give birth to a dog.
what about an ass?
Its a mix between 2 species. Or a liger?
Cross breeding species occurs even more with plants and in some cases speciation will with the new cross breed (i think this only works with plants) Albeit certain combinations may lead to fertile offspring mostly your left with infertile ones.
So this is a bit of a divergence but evolution is a long period of time and just because it doesnt look like a dog doesnt mean its not a dog. Its the genetics that are the main factor and even though we do use selective breeding the genetics do stay the same. So the offspring would be viable if you mated two extremely different looking dogs due to their genotypic similarities.
The argument of dogs is just an example to show that visually organisms can change and it doesnt take a very long time with manual selection. Now the genetic aspect is something that takes time as you are relying on generations and generations of mutations and segregation of sub populations from the original population. So we would definatley need an organism with a short generation time such as the fruit fly to observe speciation on the genetic level. This has been shown.
quote:
Cockroaches take shits just like us. Doesn't mean we evolved from them.
we didnt evolve from cocroatches since they are protostomes. (IE their mout developes before their anus.. where our anus developes first)
Our last common ancestor would have to be something like a Chaetognatha
so your argument here is something along the lines on convergent evolution (which means our common ancestor did not have the same trait).. its funny actually because an insects ass is homologous (the same cell derivation) as our mouths.. so techincally an insect uses its ass for what we would use our mouth for. so us throwing up would be homologous to an insect taking a shit. (the action of excretion thruogh an orfice neglecting digestion.)
anyways im going off topic and poking at that analogy. So essentially it comes down to cell tracking and finding out what becomes what from an embryo state. This can be done by dieing the cells and tracking them. Those cells that form certain features on an organism that are exactly the same and from the same anscestors as another organism (lets say our femur and a whale femur) are said to be homologous.
So we know that the cells in a whale femur that end up developing into a whale femur are the same cells that develope to form our femurs. So we say that we both have a common ancestor which would have probably looked something like this:
quote:
I'm giving you very conclusive arguments but it seems like you'r just rejecting my arguments out of hands. Where's you scientific objectivity?
im not rejecting anything. im just asking you to bring some sort of evidence to the table as i am doing.
Sep-05-2009 21:56
Sunsnail
Global Moderator
Registered: Sep 2004
Location:
Eh no really. There's no such thing as a "dog". It's completely subjective. There will never be a point in time when you can say that one generation is a dog and the one before isn't a dog. All species are in constant change.
Sep-05-2009 22:01
Nrg2Nfinit
ItaloDiscoAddict
Registered: Sep 2001
Location: Ottawa
quote:
Originally posted by Spam
Yes, but they exist and survive because their genetics perfectly fit the environment they live. It seems just a little bit of a grand coincidence that seals and walruses just HAPPENED to mutate into their present form at the shore of the water. Had they mutated just 10km inland, they would have been eaten by a raccoon and would currently be extinct. No?
Or were their ancestors simply fond of the water and enjoyed catching fish. Obviously without their current fins and such, they wouldn't have had much luck catching any fish, so the creatures that mutated fins and the like survived while the original genetic line died off?
sure your looking at a time period of 20 years maximum because thats how long you've been living. How long have we been observing seals?
the time arguemnt doesnt work very well in this frame of course if the species is existing and its functioning its not a conicidence that its managing well. Think about it. certain species have been exisiting for millions of years, what would be the chances that we would be catching them on their emergence or close to their extinction? we're seeing the panda almost become extinct though and it seems visually like a less plausable candidate.
To correct sunsnail, whales evolved from ungullate like creatures (i posted a picture a couple of pages back) which are like hooved animals (ungulate refers to the fact that they walk on their toes or toenails) so essentially the seal wouldnt fit into the in between class because the seals feet are actually at the tail where the whales tale does not contain the feeet. Leg appendages in the whale are found in its body segment and are vesitigial.
Sunsnails point however is a very good one. The seal has features which would seem as a nice transitional animal to evolve into a a whale like creature. there are convergent similarities between a whale and a seal such as the hind fins (they have the same function but they are not actually derived from the same cells, or in this case body parts).
the question of organisms dying off is a question about suitability for the environment. A hybrid land water mammal may have competition from a more agressive water to land variant of the same species. The competition ensues and essentially a split occurs and the aggressive more fine tuned population succeeeds and the original population dies off. This continues for several generations until the organism is fully adapted to water and thats where we have the current whales. (obviously its a long process but essentially thats the conclusion)
Sep-05-2009 22:14
Nrg2Nfinit
ItaloDiscoAddict
Registered: Sep 2001
Location: Ottawa
quote:
Originally posted by Spam
I'm pretty sure that chihuahuas are rodents.
they look like rodents.. but they are genetically dogs. Imagine we found a skeleton of a chiwawa 50 million years from now without hindsight knowledge. I think we may have a hard time classifying it lol.
It takes alot to make a classification of an organism (although scientist change the systems constantly and re arrange orgnaisms).
Sep-05-2009 22:17
Nrg2Nfinit
ItaloDiscoAddict
Registered: Sep 2001
Location: Ottawa
quote:
Originally posted by Spam
Isn't that akin to committing the same mistake that Atheists accuse religious people of making?
"We don't know, so it must be evolution." sounds very much the same as "We don't know, so it must be God." from where I'm sitting.
Sure thats fine. but do you just sit there and think.. it must be god. We don't know why people get cancer or why jimmy got cancer.. it must be god.. so be it. or do you try and find a cure?
whats the harm in finding out why and giving scientific thesis to support the facts?
Sep-05-2009 22:20
itsamemario
Divine Angel
Registered: Jun 2001
Location: Mushroom Kingdom
quote:
Originally posted by Nrg2Nfinit
This can be done by dieing the cells
[QUOTE]Originally posted by Sunsnail
All species are in constant change. [/QUOTE
Eggs-ACTLY!
And that's why you won't find a half squirrel-half whale. It died before it transformed completely into a chocolate covered marsipan-bar, errr i mean whale.
Nrg2Nfinit I feel like i'm in a lecture when reading all this". As i know very little about the development of species etc etc except: biology for psychology, but have been following this thread, interesting indeed.
You will have to start charging people for your wealth of knowledge
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Sep-06-2009 02:24
SuspicionVandit
Rapper
Registered: Nov 2005
Location: 127.0.0.1
God works in mysterious ways.
There's no proof that dinosaurs existed. The proof is this is that there is no proof that God didn't put fake bones there as a test of faith to his people.
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As i know very little about the development of species etc etc except: biology for psychology, but have been following this thread, interesting indeed.
