Comments on: Darwin and the Heart of Evolution Musings on Nature, Science, Evolution, Biology, and Education Wed, 30 Sep 2009 18:41:51 +0000 hourly 1 By: stevebee92653 Sat, 25 Jul 2009 17:37:20 +0000 RE: “…evolution pays no attention to “needs.” Species don’t evolve because they “NEED” to adapt or change some trait. Natural selection is blind to all intention and desire.”

Re: “Any individuals born larger than a certain size can no longer get enough oxygen due to the oxygen not reaching deep enough into their tissues, and so they die (or are our-competed)”
So they NEEDED oxygen to survive?

RE: “And some of these worm children will have inherited papa worm’s fluid cavity, which meant that they could survive with a slightly larger body than those without the primitive vessel, due to the oxygen distributing power of the fluid filled vessel.”
The oxygen that the NEEDED?

“Thus began the evolution of the heart.”

Which they NEEDED to survive. So, by your own words, natural selection doesn’t react to NEED, but the species that evolved the hearts got what they NEEDED to survive? That wasn’t reaction to need? Was it dumb luck? I wonder what happened to an organism that had a step in the evolution of vision, and could see light and dark, if it ran into an organism that had a little tube pre-heart. Which would win?

By: Carnival of Evolution #9 | moneduloides Sun, 01 Mar 2009 19:40:54 +0000 […] you should definitely check out Irradiatus’s post over at Biochemical Soul fittingly titled Darwin and the Heart of Evolution: In summary, the heart of Darwin’s theory of natural selection is the idea that evolution comes […]

By: Irradiatus Fri, 13 Feb 2009 03:33:19 +0000 That’s a great question!

The answer is no, it’s not a hox gene.

It is a “Tbox” gene.

The hox genes are all defined by the fact that they have a certain region termed the “homeobox” (or homeodomain) within the gene and protein. This region is responsible for allowing the proteins to bind to other genes (to turn them on or off).

Similarly, the Tbox genes are a large group of genes that all share a “Tbox” domain, which also allows them to bind to DNA.

Like the hox genes, the Tbox genes are all involved in developmental processes. But they are not related to hox genes.

Unlike the hox genes, the Tbox genes are scattered across the genome on different chromosomes. Hox genes lie in clusters (lined up along a chromosome).

So there ya go – a simplified hox/Tbox comparison.

By: ScienceTeacher Fri, 13 Feb 2009 03:19:00 +0000 Great post! Perhaps a dumb question but developmental bio was not my main focus in college (I was more of an ecology girl) – is Tbx20 one of the Hox genes, then, since it’s involved with development of so many organisms?

By: Darwin Day Linkfest - My Favorites - Biochemicalsoul Thu, 12 Feb 2009 23:57:24 +0000 […] and foremost, I would like to ask you all to read my own post, Darwin and the Heart of Evolution, which recounts a simplified evolutionary history in the development of our cherished organ – the […]

By: Christie Thu, 12 Feb 2009 13:34:16 +0000 I LOVE THIS POST.

Just thought I’d make that clear :)

Beautiful. Really, really, beautiful homage to Darwin.