Tag: biology

Life over 9 orders of magnitude

The size of things in our universe runs all the way from the 10^-19m scale of quark interactions, to the cosmic horizon 10^26m away. In these 45 orders of magnitude, life is confined to just 9 orders of magnitude, in the middle of the universal range: Bacteria and viruses can measure 10^-6m and the height of the largest trees reaches 100m. The honey fungus is 4km across. Known sentient life is 3 orders of magnitude.

Does Stress Speed Up Evolution?

Skepticism hasn’t kept Rosenberg and Austin from seeking medical applications of their findings. 1 application is cancer. His experiments suggest that putting too much stress on cancer cells by hitting them with high doses of cancer drugs could accelerate their evolution to develop drug resistance. “We give the patients as much as they can tolerate, guaranteeing the emergence of resistant cancer cells”, adding that the current aggressive approach to cancer treatment has largely failed.

Gene Expression Modeling

ML uncovers unknown features of multi-drug-resistant pathogen

Even though the model built with ADAGE was relatively simple, it had no trouble learning which sets of P. aeruginosa genes tend to work together or in opposition. To the researchers’ surprise, the ADAGE system also detected differences between the main laboratory strain of P. aeruginosa and strains isolated from infected patients. “That turned out to be one of the strongest features of the data”.

“We expect that this approach will be particularly useful to microbiologists researching bacterial species that lack a decades-long history of study in the lab. Microbiologists can use these models to identify where the data agree with their own knowledge and where the data seem to be pointing in a different direction … and to find completely new things in biology that we didn’t even know to look for.”

Intelligent Evolution

A computer scientist and biologist propose to unify the theory of evolution with learning theories to explain the “amazing, apparently intelligent designs that evolution produces.” “This simple step from evolving traits to evolving correlations between traits is crucial; it moves the object of natural selection from fit phenotypes (which ultimately removes phenotypic variability altogether) to the control of phenotypic variability. Learning theory is not just a different way of describing what Darwin already told us. It expands what we think evolution is capable of. It shows that natural selection is sufficient to produce significant features of intelligent problem-solving.”

Chips and cells

The ability to build a system that combines the power of solid-state electronics with the capabilities of biological components has great promise. “You need a bomb-sniffing dog now, but if you can take just the part of the dog that is useful — the molecules that are doing the sensing — we wouldn’t need the whole animal”. The technology could also provide a power source for implanted electronic devices in ATP-rich environments such as inside living cells.

Symmetry affects performance

We have 20 papers published as a result of our work on the Jamaican Symmetry Project. We began in 1996 with 285 rural Jamaican boys and girls with an average age of 8. 1 reason we chose rural Jamaica is that it is economically disadvantaged, and since we paid all families we recruited for the study, we got an extraordinarily high participation rate. We measured their symmetry from head to toe, including everything from ear length to foot length to their teeth, we X-rayed their hands. We measured them again for symmetry in 2006.

In 2010, we measured their sprinting speeds and – bingo! – knees stood out. There it was, it was incredible, knee symmetry alone strongly predicted sprinting speed. Not ankles, not feet, nor any other part of the body. If your knees were symmetrical when you were 8 years old, then you ran faster when you were 22 years old. That was true for males and females, and for 90m and 180m sprints alike.

This was such a striking finding that we raised the money to study elite sprinters in Jamaica. They are the best in the world. The same variable we isolated in rural Jamaicans held true for elite athletes. Knee symmetry predicted the best of the best runners. We looked at Shelly-Ann Fraser-Pryce, the current top female sprinter in the world, and her knees are so symmetrical we can’t tell them apart.

Coywolf evolution

The coywolf has evolved in the last ~100 years.

It is rare for a new animal species to emerge in front of scientists’ eyes. But this seems to be happening in eastern North America

2022-06-02: Evolution seems to be faster, perhaps in general, than expected.

The study is the first time the speed of evolution has been systematically evaluated on a large scale, rather than on an ad hoc basis. The team used studies of 19 populations of wild animals from around the world. These included superb fairy-wrens in Australia, spotted hyenas in Tanzania, song sparrows in Canada and red deer in Scotland.
“The method gives us a way to measure the potential speed of current evolution in response to natural selection across all traits in a population. This is something we have not been able to do with previous methods, so being able to see so much potential change came as a surprise to the team. Whether species are adapting faster than before, we don’t know, because we don’t have a baseline. We just know that the recent potential, the amount of ‘fuel’, has been higher than expected, but not necessarily higher than before. Evolution cannot be discounted as a process which allows species to persist in response to environmental change.”