Albion

Good grief! How seriously did you mean your apology about coming on a bit strong? I mean, you only have to do a bit of background reading and you'll see you're jumping to conclusions here. When the endosymbiosis thoery was first proposed, it really wasn't taken seriously by other scientists. However, as mro eevidence (there's that word again!) rolled in, especially (If I'm understanding this correctly) evidence showing that mitochondrial DNA was much closer to prokaryotic DNA than nuclear DNA was, the scientific community started to be convinced. Now the endosymbiotic theory is accepted.

You're posting as if you have a great big giant chip on your shoulder. Sorry, but you are. I mean, just look again at that post I'm responding to. You're in a forum with a lot of professional scientists and people with advanced science degrees, and you sound as if you'd rather do anything but accept that they know what they're talking about.

Why not go and post on the Beliefnet Creation/Evolution board for a while? A lot of the evolution supporters there are Christians. You might get useful information there while being able to let your guard down a bit.

<a href="http://www.beliefnet.com/boards/discussion_list.asp?boardID=821" target="_blank">http://www.beliefnet.com/boards/discussion_list.asp?boardID=821</a>

Hastur

If any of my kids' science teachers ever use the term "evolutionists" there will be trouble.

MarcoPolo

What kind of 'trouble?'

lpetrich

I'll add to what others have commented. An important clue as to the origins of the eukaryotic cell is in the genes. Mitochondria and chloroplasts have their own genomes, though some of their proteins are coded for in the cell nucleus. Their closest relatives are

mitochondrion -- the Rickettsia bacterium and the like
chloroplast -- blue-green "algae" (bacteria)

The closest relatives of the rest of the nucleus are less clear, however; different genes in it point to different closest relatives, suggesting some earlier gene transfer or even endosymbioses.

And endosymbiosis has happened more than twice -- some algae have "chloroplasts" that were once other algae, and that continue to have vestigial nuclei or nucleomorphs.


The next question is the origin of the eukaryotic-cell architecture, which has several extra features when compared to prokaryotic-cell architecture.

The nucleus may be a result of an earlier endosymbiosis, but one where the symbiont acquired the host's genes and not vice versa, as with the later cases.

The cytoskeleton is likely a cell-wide expansion of some structures used for pulling divided-cell genes apart.

Related to that is phagocytosis, the ability of a cell to pull in parts of its membrane and turn it into bubbles inside of itself. That may also be an extension of the cell-division mechanism.

All this is somewhat speculative, but as more is learned about cell structures and how they work, such hypotheses may eventually be tested!

Peez

I see no evidence that scigirl has forgotten how science works, but your post suggests that perhaps you are unclear on it yourself. In particular: "it remains undecided until such time as it becomes known" suggests that some things do become known with absolute certainty. In science, this is never the case. In science there always remains a certain measure of doubt, no matter how compelling the evidence. That is because science can never prove something absolutely, it can only disprove something. When, after many credible attempts to disprove a hypothesis, the hypothesis remains unfalsified, then we may accept it as a scientific fact. The evolution of living species from common ancestors is such a fact.

Peez

sciteach

I read that the Swaziland microspheres are 3.5 bn years old give or take a few. Do you really think that there was enough time (probably less than 500million years--enough time had to pass for water to accumulate from volcanic outgassing according to your rules)for something as complex as a bacteria cell to develop?(with it thousands of proteins, DNA, RNA, metabolic processes all functioning, organelles, cell membrane)

Peez

That is pretty cool, do you have a reference handy?

Peez

sciteach

Sorry, I and many others like me just dont buy macro evilution as a scientific fact. You haven't disproved creationism, or proved ME as a fact, all you have is a very powerful theory that uses common traits and some fragmentary fossil evidence to insist on a chronological progression of complexity. I will never buy it, because all those same evidences you use for evilution, I will use to convince myself of the sublime grandeur and power of the Creator. The fact that all living things share the very similar metabolic processes and cell functions just shows to me that God had a good design and used it throughout creation.

Albion

"macro EVILution"????

You have NO business teaching biology. How would you like it if a Satanist were to be in charge of teaching your kids about the Bible and the message of Jesus?

sciteach

Albion, you still haven't answered a lot of my questions. Where's Scigirl when you need her? You are still prattling on about my inability to teach biology. As I said I will teach them creationism as an alternative to evilution, and let them collect evidence and present it to the class. Maybe Ill even let them get on this forum, and then you can mess em up real good.