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You have various questions here. If I understand correctly, roughly ~2.8 billion years ago cyanobacteria started pumping large amounts of oxygen into the atmosphere. The great oxygenation event was not an instantaneous process and represents a change from one equilibrium (low oxygen) to another (20% oxygen). This abundance of oxygen and organic carbon ...


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There are multiple definitions of complexity, ranging from algorithmic complexity to computational complexity. In biology, I'd say that algorithmic complexity (Kolmogorov complexity) is most relevant. Unfortunately, we don't yet know enough about genetic circuits and all the other things that go on at the subcellular level even to make plausible estimates ...


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the trick is ovum come with a whole package of signal pathways built in before fertilization that you need to trigger implantation and embryonic development. In theory you could engineer these (search artificial ovum) but it is drastically easier and less expensive to just use existing ovum organisms produce for essentially free. could you use ovum and ...


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How many generations are required for a specific neutral mutation to reach fixation? Kimura and Ohta (1968) showed that the expected time for a neutral allele to reach fixation is $$\bar t(p_0)=-4N\left(\frac{1-p_0}{p_0}\right)\ln(1-p_0),$$ where $p_0$ is the initial frequency and $N$ is the population size. The model assumes a Wright-Fisher population (...


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The breadth of examples of environmental exposure directly influencing changes in gene expression in humans is astonishing, occurring at every developmental stage from conception to death. As an example, consider the environmental exposure to a reasonably high dose of a gram negative bacteria with lipopolysaccharide. Immune cells recognize this very ...


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I think your question is interesting, though the use of "expression" is misleading in context of your rabbit example. Examples of environmentally influenced gene-expression in humans? ... That is, a phenotype which requires BOTH a certain genetic background and particular environmental influences in order to be expressed? In the example you give, ...


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Many invertebrates possess myelin. It is a misconception that invertebrates lack myelin. The world speed record for a traveling bioelectric signal is held by the myelinated axons in the abdomen of the Penaeus shrimp! Please take a look at this website or this review to find a highly recommended comprehensive website about invertebrate myelin from about a ...


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Here are some key points about parasitoid wasp evolution: They started radiating about 120 million years ago, at the same time as flowering plants... Today they represent 10-20% of all insect species. They have accompanied the other insect species in their diversification since that time, and often undergo co-speciation... When a host species divides into ...


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