Oct 31 2005
A Control Panel within You
Read this book review in the New Yorker 10/24/2005 issue: “Turned On”
The book reviewed: Endless Forms Most Beautiful
Key terms:
Evo devo: “Evolutionary Developmental Biology”
Embryological development can provide important insights into evolution.
Noncoding DNA
Hox genes
Tool-kit Toolkit Protein
Tool-kit gene
—Used to explain why many animals look a like in embryo stage, e.g. snake embryos shows legs during certain stages, etc.
Different animal designs reflect the use of the same old genes, but expressed at different times and in different places in the organism.
The basis of this selective expression involves that part of the DNA which is noncoding. Most genes, like most light fixtures, have “switches” near them. These switches, which are made of DNA, affect only whether a gene is on in a particular cell at a particular time; they do not change the actual protein coded by a gene.
If a tool-kit protein finds and binds to a switch, it insures, through a complex molecular choreography, that a certain gene is expressed
In the end, the logic of animal development involves a long cascade: tool-kit genes effectively switch other genes on or off, some of which then switch yet other genes on or off, and so it continues throughout the assembly of an adult. If all goes well, each of the possibly trillions of cells in an animal’s body will express just the right genes: insulin in your pancreas, not in your eye.
— What I am wondering is, is there any research on how environment would selectively stimulate evolution? E.g. Could warm environment turns on some genes while cold weather turns on others?