This 2017 UK/Spanish review subject was biological variability: “No two cells in a cellular population are the same, and no two individuals of a multi-cellular species are identical-not even if they share the same genetic makeup like monozygotic twins or cloned animals. Epigenetic and gene expression variability are key contributors to phenotypic differences. There are … Continue reading A review of biological variability
This 2015 Zurich human review addressed: “A remarkable lack of discussion on the meaning and interpretation of frequently used hormone ratios. The interpretation of hormone ratios is complicated and in many cases not sufficiently supported from a theoretical point of view. Based on the assumption that the balance between two interdependent hormones determines their eventual … Continue reading Are hormone ratios useful in explaining health? Behavior? Neurobiology? Anything?
How Trauma and Resilience Cross Generations “The purpose of epigenetic changes, I think, is simply to increase the repertoire of possible responses. So let’s say, for some reason, your parents transmitted to you biologic changes that are very appropriate to starvation, but you don’t live in a culture where food is not plentiful. You’re just … Continue reading An interview with Dr. Rachel Yehuda on biological and conscious responses to stress
I curated this 2015 Georgia human study only for its use of two methods of estimating biological age. The researchers misguidedly used these techniques to help paint a scientific patina on an agenda. One of the methods was originated by a coauthor of The degree of epigenetic DNA methylation may be used as a proxy … Continue reading Using epigenetic DNA methylation markers to estimate biological age
This 2015 New Zealand human study used the same subjects of the More from the researchers that found people have the same personalities at age 26 that they had at age 3 study. The researchers used 10 biologic age markers of the subjects at age 38 to find that their biological ages ranged from 28 … Continue reading A study of biological aging in young adults with limited findings
This 2015 Harvard/MIT rodent study was of long (more than 200 nucleotides) noncoding (non-protein coding) RNAs (ribonucleic acids). These are of interest because: “Within the mammalian body, the largest repertoire and diversity of lncRNA genes outside the germ line occurs in the brain, where lncRNAs exhibit regional and cell-specific localization. The expression patterns of lncRNAs … Continue reading RNA as a proxy signal for context-specific biological activity
This fascinating 2014 human study developed the new use of a somewhat intuitive marker of aging. The researchers used the degree of methylation – an epigenetic chemical modification of the DNA molecule – as the epigenetic clock to measure biological age. The researchers found that, on average, the epigenetic age of the liver increased by … Continue reading The degree of epigenetic DNA methylation may be used as a proxy to measure biological age
This 2014 fruit fly study found: “A biologically relevant event such as finding food under starvation conditions or being poisoned can drive long-term memory in a single training session.” I don’t think that we need to discover at these extremes, though, whether or not the finding has human applicability. We do know from the Dutch … Continue reading A biologically relevant event can drive long-term memory in a single training session
This 2004 essay by an evolutionary biologist reviewed his field’s direction in the current century: “Science is impelled by two main factors, technological advance and a guiding vision (overview). A properly balanced relationship between the two is key to the successful development of a science. Without the proper technological advances the road ahead is blocked. … Continue reading Reductionism vs. reductionism
The originator of the 2013 epigenetic clock improved its coverage with this 2018 UCLA human study: “We present a new DNA methylation-based biomarker (based on 391 CpGs) that was developed to accurately measure the age of human fibroblasts, keratinocytes, buccal cells, endothelial cells, skin and blood samples. We also observe strong age correlations in sorted neurons, … Continue reading The epigenetic clock now includes skin
