Starfish Embryo Study May Explain Life Components Through Physics

Two starfish fought over their food in a bright lab at the Massachusetts Institute of Technology. A slice of defrosting cocktail shrimp was jammed against the tank's side by overlapping arms. Thousands of suction cups shook fiercely against the glass because each echinoderm attempted to snag the prize in its mouth. Nikta Fakhri, a physicist, smiled as he watched. Few physicists preserve aquatic life in their laboratories, but Fakhri has learned to care for starfish as effectively as a marine scientist. And she's growing her collection; when a reporter came recently, a few tanks were awaiting the arrival of additional sea urchins.

To comprehend how the spinning of biological gears produced the indescribably complicated business of life, Fakhri turned to physics - a science proficient at connecting microscopic and macroscopic occurrences. According to physicists, the temperature is formed by the movements of molecules, magnetism by the orientations of atoms, and superconductivity by the coupling up of electrons. Perhaps, in the appropriate circumstances, life, too, might be eloquently characterized as a property that can arise.

Fakhri has made efforts toward accounting for those situations by studying starfish embryos using physics ideas. She observes that, like other states of matter, life "breaks symmetry" - the development of an embryo, for example, separates its past from its future.

Adapting Physics Concept

Physicist Fakhri has expanded the vocabulary of symmetry-breaking to describe how proteins and other microscopic biological components work together to permit movement, reproduction, and other characteristics of life. Along the way, she has seen a strange new condition of matter that may help life impact its environment. Fakhri grew up in Tehran, Iran. Despite the repressive atmosphere for women, her parents supported her studies, and she finally made her way to prestigious universities overseas. The American Physical Society honored her with its Early Career Award for Soft Matter Research last year for "groundbreaking and inspirational advances." Quanta's recent discussion with Fakhri in her lab on the MIT campus has been abridged and modified for clarity.

Biology is a science that is truly characterized by its molecules. It has been extremely effective in finding life's components and tiny mechanics. Of course, knowing the intricacies is crucial, but there's still a great difference between understanding how, for example, a protein uses energy and comprehending how putting all these bits collectively adds up to lifelike behavior.

Physics has a slightly different stance. Researchers seek to grasp the concepts that explain phenomena of different sizes, from the extremely small to the very enormous, utilizing a form of universal language. Scientists used to think of heat as a fluid, for example. However, using thermodynamics, scientists accounted for warmth as the movement of molecules.

Describing Starfish Components

A physics approach necessitates model systems with complex behavior and self-organization on several scales. When she first arrived at MIT, a biology department group was thinking about using starfish as a model system. As researchers discussed, it became evident to him that it contained everything they needed.

Now she's even more persuaded. This summer, Fakhri worked at the Marine Biological Laboratory in Woods Hole. Starfish are echinoderms and play with echinoderms such as sea urchins and sand dollars. She was taken away by the beauty of marine life and how all echinoderms went from this spherical, symmetrical egg cell to a pentameral shattered symmetry. There is so much symmetry-breaking to investigate in this little branch of life.

The vibrating cilia around kidney cells were studied in another project. These cilia are the small hairs that help cells swim or sense their surroundings and are seen to vibrate seemingly randomly. However, after breaking down their movements, it was evident that there was a repeating pattern present--a cycle. This indicates that the system is not balanced and has an arrow of time (meaning it is moving forward in time). Later on, researchers discovered how to use the direction and size of the cycle to determine just how much out of equilibrium the cells were.

"Odd" Material Seen

The entire crystal appears to be gently jiggling with gentle ripples when looking down at it with a camera spinning at the same speed as the crystal so that it can't see the rotation. At the same time, the team researching this, Vincenzo Vitelli's group in Chicago, was developing a hypothesis in which two particles with internal batteries spin relative to one another. These particles can contradict Newton's third law of motion, which states that there is no equal action and response. The first particle has a different effect on the second particle than the second does on the first.

As reported by Quanta Magazine, when scientists press on a material composed of these spinning particles, referred to as an "odd" material, the uneven interactions between particles cause the substance to rotate. Under certain conditions, the Chicago group projected that these rotations would sync up to produce prolonged oscillations. This exploration of unusual materials in biological systems was entirely theoretical until they demonstrated that it could generate these persistent oscillations using our crystals of starfish embryos, which burn energy to spin similarly.

The biologist then discusses that cells may not have equilibrium properties but are defined by their out-of-equilibrium activity. It poses questions about whether other living systems also exploit properties like this for basic functions and if this framework is needed to understand how muscles work. It also mentions the potential for understanding living materials to lead to advancements in building materials that can perform new functions. The author desires to connect the measurable quantities learned from research to biological functions and specific types of cell mobility. This is seen as a large and ambitious goal.

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