Comments on: Extra genomes helped plants to survive extinction event that killed dinosaurs

By: brooks

brooks — Wed, 25 Mar 2009 00:22:45 +0000

great post ed! i’ve been fascinated by polyploidy for years.
it’s said that the Coast Redwood of california – a gymnosperm, of course, and so not covered by these studies – is a hexaploid, and that this may have played some role in its success as well (north america in the cretaceous and further back was once covered with vast forests of fossil redwoods remarkably similar to our modern species).
have you done any reading on the Red Viscacha-Rat, a south american rodent and one of very few known examples of successful polyploidy in mammals?

By: Phil Goetz

Phil Goetz — Tue, 24 Mar 2009 17:23:54 +0000

What do the bell-curve graphs mean?

By: Cameron

Cameron — Tue, 24 Mar 2009 03:16:48 +0000

Here's another paper from 2005 that looks at the role of duplication in angiosperm evolution. Interesting stuff. http://bioinformatics.psb.ugent.be/pdf/tree_de_bodt_in_press.pdf

By: MAL

MAL — Mon, 23 Mar 2009 23:57:39 +0000

Great, thanks so much for clarifying! Now I should just go read the paper.

By: Ed Yong

Ed Yong — Mon, 23 Mar 2009 23:48:07 +0000

First, your statement that “within 5 million years, 95% of all angiosperm species had exploded into existence…” – are you saying that 95% of the angiosperms around today evolved within 5 million years over 65 million years ago?

Gawd, did I really write that? Facepalm – this is what happens when I don’t have time to proofread… I meant lineages rather than individual species (see link in text).

Is the genome-copying referred to happening within the *lineage containing Arabidopsis*, or is the author suggesting that Arabidopsis itself is a genus that is 70 million years old?

The former.

By: MAL

MAL — Mon, 23 Mar 2009 23:27:10 +0000

Sorry to inundate you with long questions, but I really want to understand this. First, your statement that “within 5 million years, 95% of all angiosperm species had exploded into existence…” – are you saying that 95% of the angiosperms around today evolved within 5 million years over 65 million years ago? That can’t be right, because there’s been lots of turnover in angio floras since then – very few species have *that* great of a longevity. I was wondering if you’d mind clarifying that statement (there was a 95% increase in diversity maybe?).
Also, I haven’t read this paper so I might be missing a key piece of information, but the graph you posted makes it look like the author is suggesting that, for instance, Vitis vitifera originated in the mid-Cretaceous. Am I misinterpreting that? Is it instead supposed to be a representative of a whole family, for instance, or some other larger clade? Because the earliest fossils from that genus are known from the late Paleocene (59 MA), so that seems like a dramatic extension for the age of a modern *species*! Same with Arabidopsis – is the genome-copying referred to happening within the *lineage containing Arabidopsis*, or is the author suggesting that Arabidopsis itself is a genus that is 70 million years old? Again, very difficult to believe and something I found hard to sort out based on your post.
Sorry to sound so critical, I just really want to understand what’s going on here because it’s a very intriguing suggestion. Thanks!