The Primordial Soup is a Lie
You’ve read all about it in your biology textbooks: Life emerged from a stew of methane, ammonia and water that were triggered into becoming the first forms of organic organisms. This theory is being refuted.
J.B.S Haldane, the man behind the primordial soup theory, proposed that UV radiation had been the stimulus for organic compounds to begin fermentation (the process of converting molecules into energy without the use of oxygen). However, this does not include a sustained driving force, and without that, life just cannot exist.
Dr. Nick Lane and others from University College London believe that life came from the bottom of the ocean, near alkaline hydrothermal vents. These hydrothermal vents produce chemical gradients that are very similar to the ones that are found in nearly all living organisms today.
Quick lesson:
To do work, a cell typically uses a compound called ATP. Think of ATP as a fuel, similar to the kind we put into a car. However, ATP has to be made first, and cells create it by breaking chemical bonds between compounds.
Chemical bonds are broken whenever electrons are transferred -when electrons are transferred or moved, energy is released. However, energy cannot be harvested all at once – it would just get too confusing. Instead, energy is created by transporting an electron down a proton gradient. You can think of a chemical gradient as a series of escalators.
At the start of each escalator, an escort whisks the electron down them- for a price. And the price is 1 or more donations of the cellular currency, ATP.
Sound like a complicated process? Well, it is, and it didn’t just sprout up overnight. Fortunately, the natural chemical gradients present in hydrothermal vents could have been exploited by living organisms in a process called chemiosmosis, a way of harvesting compounds or elements in a process similar to osmosis. As cells evolved, they internalized their own chemical gradient, using the same kind of system that had been found in the vents.
“The reason that all organisms are chemiosmotic today is simply that they inherited it from the very time and place that the first cells evolved – and they could not have evolved with it,” states William Martin, co-researcher.
Source: Machines Like Us
Quantum Mechanics Found in Plants
Plants absorb 1017 joules of solar energy per second – and can harvest as much as 95 percent of it from the light they absorb through photosynthesis. Plants are remarkably efficient at harnessing energy from sunlight and it’s likely because they have a few tricks up their stems – a few quantum tricks, that is.
Scientists from the University of Toronto studied light-harvesting complexes, special proteins that play a key role in photosynthesis. These complexes funnel energy from sunlight into the plant’s solar cells, which are other proteins called reaction centers.
Greg Scholes, lead author of the study, isolated a few of these light-harvesting complexes from marine algae and stimulated them with incredibly quick laser pulses in order to mimic the absorption of sunlight. The researchers tracked the flow of energy as it traveled through the algae’s photosynthetic system, and noticed something peculiar. Energy from the laser pulse resides in two places at once – a state of superposition. “We always thought of it as hopping through the system, the same way that you or I might run through a maze of bushes,” explained Gregory Engels, a biophysicist whom completed a similar experiment in 2007. “But, instead of coming to an intersection and going left or right, it can actually go in both directions at once and explore many different paths most efficiently.”
“It means that quantum mechanical probability laws can prevail over the classical laws of kinetics in this complex biological system, even at normal temperatures,” explains Scholes. “The energy can thereby flow efficiently by -counter intuitively – traversing several alternative paths through the antenna proteins simultaneously. It suggests that algae knew about quantum mechanics two billion years before humans.”
So, what does that mean? Well, first of all, it means I’m surprised that algae aren’t the dominant species (I, for one, would welcome our algae overlords). Secondly, it means that plants are using the basic principles of quantum mechanics to transfer energy.
However, it’s still unknown how exactly they are able to do this. “[The protein structure] of the plant has to be tuned to allow transfer among chromophores but not to allow transfers into [heat],” states Engels. “How that tuning works and how it is controlled, we don’t know.”
Source: Science Daily
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Kin Selection Plays Evolutionary Role
Evolutionarily speaking, male homosexuality doesn’t make much sense (the article makes no mention of female homosexuality). If an organism’s main biological goal is to make sure its genes are passed on to offspring, then what kind of advantage could this sexual orientation have? A possible explanation is what evolutionary psychologists call “kin selection hypothesis.” Homosexuality may have an indirect benefit by enhancing the survival of closely related kin and relatives. In other words, they are “helpers in the nest.”
Paul Vasey and Doug VanderLaan of the University of Lethbridge, Canada tested this idea on the Pacific island of Samoa. Samoa was chosen because it has another gender category beyond the female/male distinction called the fa’afafine, people considered “neither man nor woman,” males that are exclusively attracted to adult males.
Past studies have shown that the fa’afafine are more altruistic towards their nieces and nephews than heterosexual Samoan men and women. They babysit, tutor, and help out financially far more often than others. Vasey and VanderLaan wanted to see if they were specifically nicer to their own kin, rather than just kids in general. They gave a mixed group of fa’afafine and heterosexual men and women questionnaires measuring their willingness to help their own nieces and nephews in various ways, and also their willingness to do the same for other, unrelated kids. The findings show that the fa’afafine showed a weaker link towards behaving altruistically for unrelated kids, but allocated their time and resources more efficiently and precisely towards their own kin.
According to Vasey, each fa’afafine would have to support the survival of two additional nieces or nephews to compensate for being childless. “The fa’afafine’s avuncularity probably contributes to the evolutionary survival of genes for male same-sex sexual attraction, but is unlikely to entirely offset the costs of not reproducing.”
Source: Science Daily
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The Slow Sperm Wins the Race
The well-known race of sperm to egg assumes that the fastest sperm wins the embryo. Well, yes and no. If a sperm starts swimming too fast, it tires out and dies, much like the hare from Aesop’s Tales, and pauses halfway through sprint to rest in the fallopian tubes. The pH level of the sperm affects its speed and timing: The less acidic it is, the faster it swims. However, something must trigger it into breaking away from the fallopian tube and continuing the final sprint towards the egg.
“It’s a tough job for a sperm – when it’s deposited it has to travel a long distance to the egg sites,” explains Deijan Ren. “This process has been known for many decades, but how it actually happens remained a mystery.”
However, researchers have found the mechanism that raises the sperm’s pH and gives it the final push towards the finish line. In order to increase its pH, the sperm jettisons protons. “The concentration of protons inside the sperm cell is 1,000 times higher than outside. If you just open a pore, protons will go outside- we identify the molecule that lets them out,” states Dr. Yuriy Kirichok, lead researcher.
As the sperm travels closer to the egg, a substance in the female reproductive tract causes the sperm to open its pores and release protons, prompting it to release itself from the fallopian tube and make the final dash towards the egg.
Source: Discover
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Lauren Admire wonders how the primordial soup tasted.
