Daniel Smith
Posts: 970
Joined: Sep. 2007
|
| Quote (JAM @ Mar. 09 2008,11:37) | | Quote (Daniel Smith @ Mar. 09 2008,11:10) | Let's look at the claim:
| Quote | The second overlooked aspect is the significance of genome size and of distance between distinct regions of the genome. Rapidly reproducing organisms, like Caenorhabditis, Drosophila, Fugu and Arabidopsis tend to have stripped-down genomes with relatively less abundant repetitive DNA while
organisms with longer life cycles, such as humans and
maize, have larger genomes with correspondingly more
repetitive elements (Table 1 ; Cavalier-Smith, 1985). |
So what do they mean by "relatively less" and "correspondingly more"? |
They mean that they can't support their claim.
| Quote | | Is it in relation to their own genome size or is it relative to the amount of repetitive elements in the other category (rapidly reproducing vs. longer life cycles)? |
Dan, the paper is pure hackery.
1) Genome size is very highly correlated with the amount of repeated DNA; in fact, because the same fundamental set of genes is there (remember how spectacularly wrong your prediction was?) and most DNA without a known function is repetitive, genome size is basically a function of the amount of repeated DNA.
2) The opposite of "rapidly reproducing" is "slowly reproducing," not "longer life cycles."
| Quote | | Since they say "stripped-down genomes with relatively less abundant repetitive DNA" and "larger genomes with correspondingly more repetitive elements" and immediately before that say that they are talking about "the significance of genome size and of distance between distinct regions of the genome", I'd say it is the latter. |
It doesn't matter; it's BS either way.
| Quote | | From that perspective, I think the data in Table 1 does support their claim - especially if you look at the specific species mentioned. |
Why would you italicize your bad grammar? Data (plural) either do or don't support a claim.
1) The data in the table couldn't possibly support their claim even if their claim was correct, because they offered no data on either speed of reproduction or length of life cycle (which aren't the same thing).
2) Look at two of the specific species mentioned: dog and mouse. The claimed relationship doesn't hold at all for them. IOW, they are incompetent even at dishonest cherry-picking.
If you really wanted to see if this is true, you'd look at more closely-related organisms, such as within the genus Allium. The evidence (remember, that stuff you lied about being interested in?) shows that genome size is amazingly plastic. |
I'm looking at the Allium paper right now and I can see what you're talking about w/regard to genome size. Looking at the data, I notice that all the species from the Subgenus Amerallium have larger genomes. The authors also note "a correlation between genome size and ploidy level", but it doesn't seem to me to be a strong correlation. | Quote | | A comparative analysis conducted using Mesquite (Maddison and Maddison 2003) revealed the existence of a correlation between genome size and ploidy level (Fig. 2, P = 0.031): tetraploidy is correlated with a small genome size. |
Nevertheless, I think I'm in way over my head on this one! I will defer to you that the paper proves your point. I'm not going to be able to defend the Shapiro/Sternberg paper very effectively - I'm just too new to this. I've made the mistake in the past of making grandiose claims that I could not back up and I'm beginning to see the error of my ways. So, the Shapiro/Sternberg paper must stand or fall on its own merits.
--------------
"If we all worked on the assumption that what is accepted as true is really true, there would be little hope of advance." Orville Wright
"The presence or absence of a creative super-intelligence is unequivocally a scientific question." Richard Dawkins
|
