Photoreceptors<span>: The light sensing nerve cells (rods and cones) </span>located<span> in the retina. Pupil: The adjustable opening at the center of the iris through which light enters the</span>eye<span>. Retina: The light sensitive layer of tissue that lines the back of the </span>eye<span>.</span>
It is a very interesting question - the technology is real and the research on eDNA published in a journal in 2017.
eDNA stands for enviornmental DMA sampling. It allows scientist to test water samples for the presence of the DNA of the invasive fish species. It is more effective than traditional methods of sampling because it does not require trapping or sighting of the invasive species. Water samples can be collected anywhere any time and the DNA results are as accurate and detailed as collected from the invasive species themselves. It provides a complete picture of what invasive species are there.
Answer: The idea of natural selection is that traits that can be passed down allow organisms to adapt to the environment better than other organisms of the same species.