This is the only 'tweak' I did that I thought needed mentioning the source. Since most people on Deviantart and facebook group Mandelbulb Maniacs post their parameters freely, you can easily rip off someone else's work.
But those parameters are great learning material and it makes a great starting point. Usually I don't bother mentioning where I started, because the journey has led me in such a different location that there's really no point anymore in crediting the original parameters or the person who created them. Also, because what made the original piece great is not the same as what makes the tweak (hopefully) great - its substance has changed.
In 'the branching of phyla' however, I'd used the parameters from a wonderful picture 'jungle' by p. jacqueroux, and this featured a lush jungle-scape with fern-like plants. These features are still in this piece, and even though I did change the colors, the camera and the entire beginning, the spirit of the original piece was still there and I believed it deserved credit. This is the link to the original.
Others might disagree with me and argue you always need to mention the author of the original parameters, which becomes increasingly tricky as I often also use old parameters from myself to create something new. So you'd have to credit the source of the source of the source- ad infinitum. Like a fractal.