I have two small embryos preserved in alcohol, that I forgot to label. At present I am unable to determine the genus to which they belong. They may be lizards, small birds, or even mammals. Karl von Baer (1828) The changes undergone by a developing embryo forms an hourglass: early on embryos from different species vary significantly, later on, they converge to be similar, and finally, they...
Editorial notes: This Essay was found as a ‘draft’ entry in Everything2. It was last updated on 03/05/2011. To me, molecular biology is that part of biology that is concerned with the molecules that make up biological systems. It is concerned with those molecules’ lives, and the way they interact with each other. It manipulates molecules to test hypotheses. Although it may look...
Editorial notes: This scientific analysis was found as a ‘draft’ entry in Everything2. It was last updated on 03/05/2011. In 2006 Harvard presented a short movie they’d contracted called The Inner Life of a Cell. This eight and a half minute production was a 3D animation of (ostensibly) what a cell could look like on an atomic level*. This forms the final chapter of my three...
Many drugs, and most drugs that are directed at cognitive processes (e.g. anti-depressants, hallucinogenics) target receptors. Receptors are proteins involved in the way cells in the body signal to each other. The following is a review of one particular type of receptor called the 5-HT2A receptor, and it’s role in mediating the effects of LSD. What is a receptor? Our body is made up of...
The central dogma of biology says that DNA encodes RNA which encodes proteins In the beginning, you were a single cell made up from a fused sperm and egg. This cell had 23 pairs of chromosomes which together made up all your DNA – chromosomes are what DNA looks like when it’s tightly wrapped. DNA is a long code made up of four nucleotides that form a four-letter alphabet – ACGT...
This is not an introduction to chemistry or even to atomic theories. It’s an introduction to what atoms are with the aim of providing enough background to be useful for understanding molecular biology. Introduction “Nothing exists except atoms and empty space; everything else is opinion.” (Democritus c. 400 BCE) Atoms are the building blocks of the world. There are different...
LINE-1 retrotransposons are sections of DNA which are capable of copying themselves into another part of the genome. Although traditionally considered to merely epitomize the concept of the selfish gene, more recently they have been suggested to have physiological functions. Here I discuss the incredibly fascinating hypothesis that LINE-1 retrotransposons may be important in generating neuronal...
Editorial notes: In November 2010, Shai begins the second phase of his intellectual journey with an essay dedicated to scientific summation. Throughout 2010 Shai’s writings are focused primarily on book reviews with the occasional venture into reviews of science. This focus shifts in 2013 when Shai produces 24 science-related compilations. Between November 2010 and June 2016, Shai produces 60...
