"Since the 1980s it has become known as horizontal gene transfer" - when exactly?

Question

From an article on biology

The discovery of horizontal gene transfer (HGT) can be traced to 1928 when Fred Griffith reported the transfer of genetic material from heat-killed virulent Streptococcus pneumoniae to an avirulent form of the bacterium by a process he described as transformation (Bushman, 2002). It wasn’t until 1946 that other forms of non-reproductive gene transfer between organisms were identified and variously described as conjugation, transduction, recombination, rearrangement, linkage disequilibrium, etc. (Bushman, 2002). Since the 1980s these different examples of gene transfer have become known collectively as either horizontal or lateral gene transfer (Gogarten et al., 2002; Koonin et al., 2001; Ochman et al., 2000; Syvanen, 1994).

When exactly did they become known as HGT? In early 1980s? Or at some undefined point between the 1980s and today? Were they known as such on 1 January, 1990?

The use of become for some reason seemed strange to me. I'm not sure though.

Why "become", and not "been"?

Since the 1980s these different examples of gene transfer have been known collectively as either horizontal or lateral gene transfer.

Answer 1

There's no "exactly" to be discerned here.

The object of temporal since is always understood to be a point in time, not a timespan; this is true even when the "point" is very fuzzy.

Thus, if I say "I have been working since yesterday", I am understood to mean "I began working yesterday and have continued doing up to the present." You have no way of knowing whether I began at 0:00:01 or 8:00:00 or 23:59:59 -- just sometime yesterday.

Consequently, we understand "since the 1980s" to mean that this nomenclature came into effect at some point in the 1980s and has continued to be in effect ever since then. It is no more (or less) specific than that.

[Don't be misled by that has become known as - this is merely a common, albeit slovenly, way of saying has been known with increasing frequency as.]

Answer 2

I think the phrasing here might be deliberately vague, because there is not some single point in time where everyone started using the same terminology. Sometimes terminology evolves over time, particularly in the scientific community as discoveries occur and are published after-the-fact, often unheralded except in scientific journals.

From the wording here, I'd say this:

• Before the 1980s, these types of gene transfer were either unknown, or else were not yet referred to by this name. (In this case, we know it's the latter, because the except says that these have been known about since 1946.)

• At some time during the 1980s, this terminology began to creep into the vernacular.

• At the current time, this terminology is more widely used, if not firmly entrenched.

That's how I'd interpret it. So, to answer your question:

When exactly did they become known as HRT?

It didn't become known by that term at an "exact" time; the terminology evolved. As for the use of become, NOAD says that verb means:

begin to be

and that's what I think happened here. We could say, "Beginning in the 1980s..." but that's somewhat implied by the use of become.