Tag: evolution

Why males?

why males? why do so many complex organisms have a whole sex which does not bear offspring? One hypothesis is that males are good for purging genetic load via sexual selection. On a genetic level all individuals carry deleterious mutations, which they pass on to their offspring. But, because of sample variance in transmission, there will be a distribution of outcomes in any given set of offspring. By chance some individuals will exhibit a higher load of deleterious alleles, while others will carry fewer alleles. If this load is correlated to traits which are visible to the opposite sex, then excess load every generation can be purged through reproductive skew

Somatic mutations

If somatic mutations are common in healthy bodies, then biomedical researchers can no longer assume that DNA aberrations point toward the causes of disease. Doctors won’t be able to trust that the DNA found in a blood or saliva sample actually reflects the gene sequences in the heart or the liver. Should somatic variation turn out to be not just common but also good for you, it will undermine the longstanding presumption that the healthiest genome gets replicated with perfect fidelity. The most highly functional bodies may be the ones that permit a little mutation, that encourage a certain amount of genetic wildness and disorder within

not only are you 90% bacterial, but the human parts of you can’t get their shit together.

within our bodies our cells are not all created equal at the genomic level. In other words, we are mosaics.

Viruses most ancient life?

these viruses “represent a form of life that either predated or coexisted with the most recent organism from which all other organisms on Earth are descended. If giant viruses are as old as Caetano-Anolles’ calculated, the implications are staggering. It means that a giant virus or one of its ancestors existed before other types of life and may have played a major role in shaping life as we know it. This could mean that viruses are one of the dominant evolutionary forces on this planet and that each organism has a deep, viral past.

2021-09-01: See also Giruses, giant viruses, which may have been there since the beginning.

Predicting mutations

soon it may even be possible to make evolutionary forecasts. Scientists may not be able to predict what life will be like 100 million years from now, but they may be able to make short-term forecasts for the next few months or years. And if they’re making predictions about viruses or other health threats, they might be able to save some lives in the process.

a procedure to predict influenza mutations every year with 90% precision, helping to produce the right vaccines for that season.

We can analyze any mutation, even those that haven’t been identified yet. This allows researchers to predict whether a novel mutation is likely to be dangerous or harmless — in essence, performing a screening test

and another one

10 years of work at Johns Hopkins has yielded a computer program that predicts, with far more accuracy than current methods, which mutations are likely to have the largest effect on the activity of the “dimmer switches” (which alter the cell’s gene activity) in DNA — suggesting new targets for diagnosis and treatment of many diseases.