An example of how epigenetic switching works
https://bmcresnotes.biomedcentral.com/articles/10.1186/s13104-021-05600-0
Excerpts: "A gene enrichment analysis for differentially expressed genes, including those obtained from winged vs wingless and flight vs flightless genes comparisons, revealed that carbohydrate metabolic process-related genes were highly expressed in the winged stick insect group. We also found that the expression of the mitochondrial enolase superfamily member 1 transcript was significantly higher in the winged stick insect group than in the wingless stick insect group. Our findings could indicate that carbohydrate metabolic processes are related to the evolutionary process through which stick insects gain the ability of flight."
"In this study, we compared the nutrient metabolic systems of flight-winged, flightless-winged and flightless-wingless stick insect groups using our midgut transcriptome data and those from public database and found the expression of transcripts related to the production of energy in carbohydrate metabolic processes in the winged stick insect groups."
Excerpts: "A gene enrichment analysis for differentially expressed genes, including those obtained from winged vs wingless and flight vs flightless genes comparisons, revealed that carbohydrate metabolic process-related genes were highly expressed in the winged stick insect group. We also found that the expression of the mitochondrial enolase superfamily member 1 transcript was significantly higher in the winged stick insect group than in the wingless stick insect group. Our findings could indicate that carbohydrate metabolic processes are related to the evolutionary process through which stick insects gain the ability of flight."
"In this study, we compared the nutrient metabolic systems of flight-winged, flightless-winged and flightless-wingless stick insect groups using our midgut transcriptome data and those from public database and found the expression of transcripts related to the production of energy in carbohydrate metabolic processes in the winged stick insect groups."
"We estimate that different host plants would affect the expression profile of transcripts involved in the carbohydrate metabolic process in the insect midgut because the amount of nutrients depends on the condition and development of their host plants."
"We extracted genes with transcript per million (TPM) values higher than 2-fold for the subsequent gene set enrichment analyses. The examination of the differentially expressed genes in the flight and winged stick insects showed that the expression of 427 unique genes was elevated in the flight group, whereas the expression of 2636 unique genes was downregulated in the flight group."
"It is known that the flight fuel differs depending on the type of insect. The transition from rest to flight in many insects is accompanied by a 100-fold increase in the metabolic rate. Therefore, sufficient enzymatic activity is needed for the production of energy in flight. Short-distance-travel insects use carbohydrates as their main energy source. The preferred energy source of long-distance-travel insects is carbohydrates, and these insects then change their energy source from carbohydrates to lipids. In most insects, carbohydrates are used as the main energy source because carbohydrates are hydrophilic substances and move faster than lipids into insect bodies. Therefore, our findings might point to some gene expression bias in stick insects with evolutionary flight ability."
My comment: This is a typical example of an epigenetic mechanism that helps organisms adapt to changing environment. These adaptive changes have nothing to do with random mutations and they never result in any kind of evolution. These kind of mechanisms point to Intelligent Design and Creation. Don't get lost, my friends.
