Myers...please take genetics course 101

Well, now our friend Myers is trying to persuade us saying that creationists think that all mutations are harmful or dangerous (at least from a creationist view...) Wrong my friend! Of course creationist scientists know that there are mutations, but there are different mutations and he must know that. Probably the guys commenting in his blog know anything about biology (...and I think it's true), but there is a course called Genetics 101 friends...

The BBC has an article on the recent direct measurement of human mutation rates, and while it's not a bad article, it does seem to express the view that the result is something novel. It's not; it's a confirmation of a standard measure that scientists have known about for a long, long time. We have estimated the number of novel mutations in newborn human individuals to be somewhere between a hundred and a few hundred (best estimates were on the order of 150) based on a couple of facts.

We've had measurements of the fidelity of the enzymes that catalyze replication, and since we know both the per nucleotide rate and the number of nucleotides, it's straightforward to calculate the average number of errors per replication event. We've also had estimates from the measured frequency of spontaneous mutations in human disease genes that have given answers in the same ballpark. The only thing new in this recent study is that they sequenced the Y chromosomes of a group of related men and directly tallied up the new mutations, confirming that the previous calculations were roughly correct.

Like I say, it's not a bad article, but if you really want the best summary of the work, you should be reading Sandwalk.

It's useful information for the next time you're in a debate with a creationist, too. They often assert that all mutations are harmful, but clearly, they can't be: they're almost entirely neutral. That creationist is carrying over a hundred new mutations that his parents lacked, and his children will each have over a hundred more, and his grandchildren a hundred yet again. What we have going on is a great churn of frequent change, just change, not a pattern of directional variation that either degrades or elevates us.

Have a good day!

Source

'Glow-in-the-dark' red blood cells made from human stem cells

Victorian stem cell scientists from Monash University have modified a human embryonic stem cell (hESC) line to glow red when the stem cells become red blood cells.

The modified hESC line, ErythRED, represents a major step forward to the eventual aim of generating mature, fully functional red blood cells from human embryonic stem cells.

The research, conducted by a team led by Professors Andrew Elefanty and Ed Stanley at the Monash Immunology and Stem Cell Laboratories that included scientists at the Murdoch Children's Research Institute, was published in today's issue of the prestigious journal, Nature Methods.

The work, funded by the Australian Stem Cell Centre (ASCC), will help scientists to track the differentiation of embryonic stem cells into red blood cells.

Whilst hESCs have the potential to turn into any cell type in the body, it remains a scientific challenge to reliably turn these stem cells into specific cell types such as red blood cells. The development of the ErythRED embryonic stem cell line, which fluoresces red when haemoglobin genes are switched on, is an important development that will help researchers to optimise the conditions that generate these cells.

Professor Joe Sambrook, Scientific Director of the ASCC said that "The elegant work of the Elefanty-Stanley group unlocks the entrance to the long sought and elusive differentiation pathway that leads to expression of adult haemoglobin genes"

"Not only will the ErythRED cell line lead to more efficient creation of red blood cells from human embryonic stem cells, but these cells are a crucial tool for monitoring the behaviour of the cells when transplanted into animal models" said Professor Andrew Elefanty.

Source: Monash University - More Info