An ancient divergence among the bacteria.
Balch WE, Magrum LJ, Fox GE, Wolfe RS, Woese CR.
Abstract
The 16S ribosomal RNAs from two species of methanogenic bacteria, the mesophile Methanobacterium ruminantium and the thermophile Methanobacterium thermoautotrophicum, have been characterized in terms of the oligonucleotides produced by digestion with T1 ribonuclease. These two organisms are found to be sufficiently related that they can be considered members of the same genus or family. However, they bear only slight resemblance to "typical" Procaryotic genera; such as Escherichia, Bacillus and Anacystis. The divergence of the methanogenic bacteria from other bacteria may be the most ancient phylogenetic event yet detected--antedating considerably the divergence of the blue green algal line for example, from the main bacterial line.
J Mol Evol. 1977 Aug 5;9(4):305-11.
http://www.wired.com/wiredscience/2011/03/deletion-human-evolution/
ReplyDeleteIs this true?? Tell me, Schmientist!!
The original paper appears in the following: Nature 471, 216–219(10 March 2011).
ReplyDeleteFirst, they did a comparison of the human genetic sequence to the chimpanzee genetic sequence. They found that there was a large region of DNA that is present in chimpanzees and macaques, but not in humans. From there they checked for genes that code for proteins and found one that codes for an androgen receptor. They tested where this gene was expressed when tagged with a reporter gene in mouse embryos and they found that it was expressed in the "genital tubercle." Previous data has shown that when mice or chimpanzees are missing the androgen receptor described in the paper, they fail to form penis spikes.
They think that this deletion has something to do with monogamous relations between humans and increased paternal care of offspring.
As for the truth of research, that is a tall order. It would be more productive to consider the evidence in the context of our current understanding of the topic. The evidence in the paper, which I do not show because of copyright laws that could possibly get me in trouble, seems plausible. I am definitely not an expert in that field, but from their presentation, it sounds really solid.