Recent content by mark!

How?

So what’s the answer to my question, then?

So time is something separate/additional to space, is what you’re saying?

Infinity doesn’t make any sense at all. It’s a concept made up by humans. The decimals of pi are infinite, sure, but numbers are made up by us too you know. Ok but let me get this straight, you assume that if one would travel the universe in a certain direction, you would ALWAYS be travelling...

The flat universe is NOT infinite. It can’t be. If it would never end, it could have never begun (because space = spacetime). Infinity only exists in mathematics, not in the real world.

Sex determination NOT due to external/environmental factors, then?

In which animals is sex determination based on food availability? And as a side question: In which animals is sex determination based on the presence of predators? Let me elaborate on both questions. Females of the common reed frog have shown to exhibit a sex change, which is thought to occur...

[Mentor Note -- Merged accidental double-thread-start] In which animals is sex determination based on either food availability. Females of the Common reed frog have shown to exhibit a sex change, which is thought to occur due to low male density in the environment, so that's not quite what I...

@BillTre Thanks, but to make matters even more complicated: "Recent data have shown that the distinction between embryonic and extraembryonic endoderm is not as strict as previously thought due to the integration, and not the displacement, of the visceral endoderm into the definitive embryonic...

I'm getting contrasting information from different sources about the relationship between the hypoblast (one of the two structures that make up the inner call mass) and the endoderm (which will form a few days later on, after gastrulation, and which will eventually give rise to the GI tract and...

For my question it's irrelevant, because I'm interested in the relationship between adrenalin and melanin, which both have tyrosine and dopamine as their precursors. What exactly happens in between, such as different enzymes that are involved, that doesn't change the starting material or end...

Tyrosine -> Dopamine -> Melanin Tyrosine -> Dopamine -> Adrenaline How is this not the same pathway? That's irrelevant, it has nothing to do with the pathway itself. Interesting stuff, but I'm not talking about this gene. Your remark is comparable to the notion that vitamin D has also...

Do you have anything to support your 'no'? I've already provided two papers to support my 'yes'. Let me add a third one: "Catecholamines were first shown to play a role in pigmentation in nonmammalian tissues, especially amphibian chromatophores where both α- and β-adrenergic receptors are...

OK, thanks! What about you, @jim mcnamara, is a black skin related to melanin's relation with adrenaline? Yes/no.

White spotting in domesticated animals is not the same phenomenon as albinism. It may have the same phenotypic effect, but that's due to a very different genotypic alterations. So in reference to my question, this is not relevant information. That's why you possesses some adrenaline, but not a...