The two principal abiogenic petroleum hypotheses, the deep gas hypothesis of Thomas Gold and the deep abiotic petroleum hypothesis, have been scientifically reviewed without confirmation. Scientific opinion on the origin of oil and gas is that all natural oil and gas deposits on Earth are fossil fuels and are, therefore, biogenic.
In short a Thru Axle design incorporates a solid rod or hollowed shaft that passes directly through the hub and both legs of the fork or rear frame members. It is then secured to one side of the fork leg or rear frame member (typically on the brake rotor side) by a threaded mechanical connection.
Basically it's an axle that's threaded at one end and has a platform of sorts at the other. The threaded end goes into the crankarm and the platform goes under your foot, then you push. The left side pedal has a reverse thread to keep it from unscrewing from something called precession as you ride.