presumably = probably? = most likely?

Words like "presume" and "appears to be" infer that they've developed a hypothesis that needs further study before it can be proven.



"on a regulatory basis = with a regulatory machanism?"

Yes, but it's mechanism
.

If that was a hypothesis, how could the researchers say " we could locate "? That is why I get confused.

It comes down to an experimental model, data, and conclusions. They ran an experiment with a particular model, collected data, and drew some conclusions, which are now being stated as fact couched in fuzzy terms like "appears to" and "presumably".



Additional studies by other researchers will be done to try to disprove the model (hopefully prove it by failing to disprove it) and then continue on with the next round of hypotheses.

presumably = probably? = most likely?

What do you mean by "If so, how you locate them?", Ori?

First,

probably = likely = should [as regards the epistemic certainty level but not the usage]

'probably/likely/should' occupy a level of certainty range that equates to above 50% to somewhere around 90%.

This scale will show you the relative epistemic modal/periphrastic modal level of certainty range:

+++++++++++++++++++++++++++++
110% intensifiying adverbs [eg definitely, with verbs of 100% certainty, eg will/would/be going to/etc

100% [verbs of 100% certainty, eg will/would/be going to/etc]

90 to 99% almost certainly/must

51 to 89% probably/likely/should

26 to 50% may

1 to 25% might

0% [negated verbs of certainty will not/ etc

-10% intensifiying adverbs/adverbial phrases [eg 'definitely', with verbs of 100% certainty, eg will/would/be going to/etc

++++++++++++++++++++++++++++

Though the two modal verbs 'must' and 'should' equal the epistemic range of their counterparts [see scale], they are used in different situations. The semi-modal/periphrastic modal forms, eg almost certainly/probably/likely, are used for more pure speculation whereas the modal 'should' is used when there is some greater intimate knowledge of a subject.

Imagine that JPB and me are asked about her husband's whereabouts at different times of the day. I don't know much of anything about either of them.

Because JPB has personal knowledge of her husband, she would likely express it with 'should' or 'must', "he should be at work"; "he must be at the golf course", whereas I, not having personal knowledge, and even if I had the necessary knowledge to put me in the 'probably/likely/should' range, I might well use 'probably' or 'likely' as it's more speculative on my part.

Similarly, a scientist or someone else with intimate/greater knowledge of an experiment or a process, again may well use, "This should work" whereas someone with less familiarity may use, "This likely will work".

There is a similar connection for 'must' but because it has a different meaning, it functions in a slightly different way than does 'should'.

Epistemic/level of certainty 'must' means "With all the information I presently have, my logical deduction is that ..." .

Because these modals cover such a wide range of certainty, we have intensifiers such as 'most' to show that our sense of sureness is higher or lower in each specific range. In speech we can also add emphasis/intonation to these words to show a position within each specific range, for example,

I miiiiiiight go to Tokyo next month, but moooost probably, my boss will send me to London.

So, most likely = most probably.

'could' and 'can' do not express a specific range so they don't fit in the 0% to 100% scale. All they say is "It's possible that ...". In your example. below, 'could', in bold, can be paraphrased as,

it's possible that we can/could locate

Context:
The question is however: how does this activity shape the morphology of the whole organism? "Using various experiments, we were able to demonstrate that this RNA family plays a key role in mammary gland development and we could locate where these molecules presumably intervene on a regulatory basis," explains Chowdhury.

So, now to 'presumably'. As you know, this is all speculative. Modal verbs and periphrastic or semi-modals, when used epistemically, are used to convey an individual's sense of certainty.

What this person is saying with 'presumably' is this,

"Using various experiments, we were able to demonstrate that this RNA family plays a key role in mammary gland development and it's possible that we could locate where these molecules probably [or even] most probably intervene on a regulatory basis,"

Note that they got to this point, Ori, by 'various experiments'. These experiments told them things that raised their level of certainty pretty high. I will suggest from the limited context that I have that some of them could be [=by my thinking, it's possible] very close to a 'must/almost certainly' which would be expressed by,

"Using various experiments, we were able to demonstrate that this RNA family plays a key role in mammary gland development and it's possible that we could locate where these molecules almost certainly/must intervene on a regulatory basis,"

Those fuzzy terms are qualifiers of fact, JPB, because the scientists don't want them, at this point, to be taken as fact. Two of the ways that we have to express such a situation is with adverbs and modal verbs.

This,

-10% intensifiying adverbs/adverbial phrases [eg 'definitely', with verbs of 100% certainty, eg will/would/be going to/etc

should have read,

-10% intensifiying adverbs/adverbial phrases [eg 'definitely', with negated verbs of 100% certainty, eg will/would/be going to/etc

Thank you both.

The two tissues = the milk duct and what?

How is this relevant at all?

I have no idea, Ori, as it doesn't say and certainly I'm no expert on what goes on inside of mammaries or mammary glands.

I got an idea! Who cares? Why don't we go masturbate, it feels better.

The ESL/EFLs who are trying to better understand and use English care.

Can you not already FULLY communicate whith every individual you now know or ever will? Where's the need to better understand English?

milk duct and glandular tissue, I think JTT.

You have to understand what ESL/EFL means in order for you to grasp the significance of what I told you, N.

No. YOU need to read my posts, silly. What's the point of understanding English beyond the use of communication?

Dont feed the chooks JTT. They only scatch for more.

You're probably right, Dadpad.

And you seek to learn into a bottomless pit, to no avail.

That's right, feed on his thoughts.........as you can't possibly counteract what I previously stated.