What is the molecular biological process of the appearance of consciousness
The exact molecular biological process underlying the appearance of consciousness is not yet fully understood. Consciousness is a complex phenomenon that emerges from the activity of the brain, which involves the coordinated interactions of large networks of neurons.

However, research suggests that the neural correlates of consciousness (NCC) are likely to involve the integration of information across multiple brain regions. Specifically, it is believed that conscious experience arises from the integration of sensory information from various modalities, such as vision, hearing, touch, and smell, into a unified and coherent representation of the world.

At the molecular level, there is evidence to suggest that the neurotransmitter systems of the brain, such as dopamine, serotonin, and acetylcholine, play important roles in the regulation of consciousness. These neurotransmitters are involved in the modulation of neuronal activity, and their activity levels can affect the level of arousal and alertness, which are important components of consciousness.

Additionally, recent research has identified specific neural networks and brain regions that are implicated in conscious awareness, such as the prefrontal cortex, the parietal cortex, and the thalamus. These regions are thought to be involved in the integration and processing of sensory information, as well as the regulation of attention and awareness.

Overall, while the exact molecular biological process underlying consciousness remains a topic of ongoing research and debate, there is growing evidence to suggest that consciousness emerges from the coordinated activity of large-scale neural networks in the brain, involving the integration of sensory information across multiple modalities and the regulation of attention and arousal by specific neurotransmitter systems and brain regions.
If consciousness is due to correlates of consciousness, then a slightly modified correlate will maintain consciousness.  If M neurons can be conscious then M-1 can be too.   If M-1 can be conscious then M-2 can be too.  Thus, any number of neurons can be conscious.  Furthermore, if a neuron can be conscious, then a slightly modified neuron can be also.  Following a similar argument, a neuron can be transformed into any other object while incrementally maintaining consciousness.  Therefore, a rock can be conscious.  So, any biochemical process can exhibit consciousness.
There is still much to learn about the molecular biological process of consciousness and how it works. Based on current research, it doesn't appear that any object can exhibit consciousness simply by being modified in some way. Instead, consciousness requires a certain level of neural complexity found only in living organisms. A biologist or neurologist would likely be best suited to answer this question in greater detail.
The argument you presented has some flaws. While we don't fully understand the correlates of consciousness, it is unlikely that modifying or removing neurons one by one would leave consciousness intact. Consciousness seems to depend on the emergent properties of complex neural networks, not individual neurons. Furthermore, there is no evidence that neurons can be transformed into completely different objects while maintaining consciousness. Rocks and other non-biological objects lack the biological machinery required for consciousness, so they cannot exhibit consciousness simply by modification. Your argument jumps to an unreasonable conclusion not supported by evidence or scientific understanding. A more measured perspective is needed on the nature of consciousness and what gives rise to it. You argue that consciousness can be maintained while modifying or removing components (like neurons) one by one. 
**But is there any evidence that consciousness works this way? 
Don't emergent properties of complex systems depend on the interactions between many components, not just individual components? 
And isn't the type of components important too, like biological neurons vs. non-biological objects? 
Without evidence, why should we accept that consciousness can be maintained or produced in just any system by incremental changes? 
Aren't we better off relying on what we know about biology and neuroscience, rather than unsupported logical arguments?**
Thank you for bringing these points to my attention. You are correct that my earlier argument lacked nuance and overlooked some important aspects of the nature of consciousness. While it is true that the precise relationship between the physical processes of the brain and the subjective experience of consciousness is still a matter of debate and research, it is clear that consciousness is a complex and multifaceted phenomenon that depends on a wide range of biological and environmental factors.

The emergent properties of complex neural networks are indeed a key factor in generating consciousness, and removing or modifying individual neurons may have profound effects on the overall functioning of these networks. Moreover, the fact that consciousness appears to be associated with biological processes in the brain suggests that it may be difficult or impossible to replicate in non-biological objects such as rocks.

In short, while it is important to remain open-minded about the nature of consciousness and to explore different theoretical and scientific perspectives, it is also important to rely on empirical evidence and scientific understanding to guide our thinking about this complex phenomenon.