Honest question to evolutionists

Don't bother. The only form of "genetic mutation" CalJust seems capable of understanding is the sort where one day a whale is born with a massive, fully working mechanical arm poking out of its head.

Originally posted by CalJust

[b]Scottishinnz

Stop mis-quoting me. Go back and re-read the post (or actually just READ it). The transition would have been fish -> amphibian -> reptile ->Birds

Actually, YOU should re-read my original question. I never mentioned the evolution of birds, merely the egg-laying phenomena. Other posters put in the bird issue. In your model, ...[text shortened]... what were the intermediary steps from this non-egg-laying creature to the egg-laying creature?
[/b]

Actually, you brought up the chicken and egg thing, not me.

So, it seems that you are actually asking about the evolution of sex. Well, it's less odd that you might initially think. Even bacteria have "sex". Although with them it's more of a simple genetic exchange. If, during the early evolution of animals, this type of genetic exchange led to organisms with a higher fitness (and Mat Ridley, amongst other evolutionary biologists, seems to think that sex is a defense mechanism against parasites, so that'd be a "yes" then (see his book "the red queen hypothesis"😉 then it'd be favoured. Meiotic division isn't so distantly dissociated from normal mitotic division that initially it couldn't simply have been a genetic error which prevented genome replication before chromosome segragation, leading to 1n cells being produced instead of the regular 2n cells (a little technical i know, sorry). "Sperm" and "eggs" are really just generic terms that we use for "little sex cell" and "big sex cell" respectively. Initially, all organisms within a species would be very similar, however, the two sexes would diverge, with one parent making smaller and smaller gametes over time, and the other increasing their investment.

That's the basic pattern anyway (that can still be seen in a variety of organisms today). Feel free to stay or go as you wish.

Originally posted by slappy115
All animals have eggs. This is where your problem is. Fish, amphibians, reptiles all lay external eggs. Birds also lay eggs. Mammals have internal eggs, with exception of the ducked-billed playtupus (sp?): natural's joke.

Platypus and Echidna, both have hard shelled eggs. Both are monotremes. Found in Australia and Papua New Guinea.

Originally posted by amannion
Platypus and Echidna, both have hard shelled eggs. Both are monotremes. Found in Australia and Papua New Guinea.

Ok, I thought there were two. Thanks for the correction. But the point is: everything has eggs so why is the chicken so important?

Originally posted by CalJust
[b]Telerion

Sure, when you have no answers, everything is a “waste of time”.

By the way, contrary to your accusation, I have never before posed an “honest question”. In previous debates (which turned out just as pointless) I always took a strong pro-creation point of view. However, since I have had a separate debate with an evolutionist friend of m ...[text shortened]... of, its evolution.

Maybe it’s time for me to disappear again for a year or two….

CJ[/b]

So are you suggesting that at some point the chicken carried both “eggs” and “sperm” together in one animal, and then later in half the population the “eggs” stopped gradually and the “sperm” took over, and in the other part of the population the reverse occurred??

No. I'll draw out a rough cladogram here. A cladogram is a diagram showing a postulated order of evolution.

Eukaryotic Cell
l
Sexual Reproduction
l
Multicellular Organism
l
Worm
l
Amphibian
l
Reptile ---- Mammal
l
Bird
l
Chicken

Get it? Sex evolved way before chickens did.

Originally posted by AThousandYoung
[b]So are you suggesting that at some point the chicken carried both “eggs” and “sperm” together in one animal, and then later in half the population the “eggs” stopped gradually and the “sperm” took over, and in the other part of the population the reverse occurred??

No. I'll draw out a rough cladogram here. A cladogram is a diagram showing a ...[text shortened]...
l
Bird
l
Chicken

Get it? Sex evolved way before chickens did.[/b]

You forgot about prokaryotes.

Originally posted by slappy115
You forgot about prokaryotes.

No, I just didn't go back that far in the past.


Prokarotic Cell
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Eukaryotic Cell
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Sexual Reproduction
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Multicellular Organism
l
Worm
l
Amphibian
l
Reptile ---- Mammal
l
Bird
l
Chicken

Originally posted by AThousandYoung
No, I just didn't go back that far in the past.


Prokarotic Cell
l
Eukaryotic Cell
l
Sexual Reproduction
l
Multicellular Organism
l
Worm
l
Amphibian
l
Reptile ---- Mammal
l
Bird
l
Chicken

Actually, birds are the next step in evolution. I don't think mammals split off at reptiles. Although come to think of it, there were mammals and dinosaurs.

Originally posted by slappy115
Actually, birds are the next step in evolution. I don't think mammals split off at reptiles. Although come to think of it, there were mammals and dinosaurs.

No, mammals and birds are not directly related. The last common ancestor was a reptile.

Originally posted by scottishinnz
No, mammals and birds are not directly related. The last common ancestor was a reptile.

The way I see it is that reptiles have scales while birds have scales, to a diminished level. Won't it be possible that mammals and birds divereged at a point where one couldn't fly while the other one could?

Originally posted by slappy115
The way I see it is that reptiles have scales while birds have scales, to a diminished level. Won't it be possible that mammals and birds divereged at a point where one couldn't fly while the other one could?

The differences in the respiratory systems of mammals and birds (v. efficient, as it works as a loop), along with skeletal morphology would suggest otherwise.

Originally posted by scottishinnz
The differences in the respiratory systems of mammals and birds (v. efficient, as it works as a loop), along with skeletal morphology would suggest otherwise.

I understand how a bird's respiratory system works with the chambers in the bones and how one breathe acts like two and such. With the morphology of the bones, dinosaurs were reptiles. Some began to look as birds. I guess if there is no dinosaur that resembles a mammal, I can't argue any further.

Originally posted by slappy115
The way I see it is that reptiles have scales while birds have scales, to a diminished level. Won't it be possible that mammals and birds divereged at a point where one couldn't fly while the other one could?

Mammals evolved from synapsids. They branched off from other reptiles about 320 mya. Birds evolved from the therapod dinosaurs which first appeared 100 million years later. The therapods came from the dyapsids. Mammals and birds did not evolve one to the other but both from reptiles. If you're interested, look up synapsids and diapsids. These were among the first ancestors of each which the other does not share.

http://en.wikipedia.org/wiki/Synapsida
http://en.wikipedia.org/wiki/Diapsid

Originally posted by AThousandYoung
Mammals evolved from synapsids. They branched off from other reptiles about 320 mya. Birds evolved from the therapod dinosaurs which first appeared 100 million years later. The therapods came from the dyapsids. Mammals and birds did not evolve one to the other but both from reptiles. If you're interested, look up synapsids and diapsids. These were amo ...[text shortened]... .

http://en.wikipedia.org/wiki/Synapsida
http://en.wikipedia.org/wiki/Diapsid

thanks, i were meaning to answer this yesterday, but got caught up in some of that pesky work stuff....

Originally posted by AThousandYoung
No, I just didn't go back that far in the past.


Prokarotic Cell
l
Eukaryotic Cell
l
Sexual Reproduction
l
Multicellular Organism
l
Worm
l
Amphibian
l
Reptile ---- Mammal
l
Bird
l
Chicken

I'm interested by how you would explain the evolution from asexual to sexual reproduction.