user16866: I've thought about creating a new tag for etymology on a number of occasions, but have always hesitated to do so.
I've seen a number of questions on Bio.SE where etymology is specifically asked about (e.g., here, here and here) or strongly referenced (e.g., here or here). 
I've seen the terminology tag employed in some of these instances, which I find appropriate, but the true focus of the question or answer is sometimes more specifically etymological. 
However, the English.SE site is already a valid place to submit etymology questions, and since etymology is more language-focused, would this tag be off-topic here?
My opinion is no, an etymology tag would be on topic and would possibly garner better response from fellow scientists (vs. those stinkin linguists :p).
I'm interested in other's opinions.

user3624: To me, tags are created ad-hoc at SE-sites when there is a need for them. The point of them is to meaningfully categorize questions, and relate questions with similar subjects. It is true that we have tags at different hierarchical levels, and e.g. many specialized tags under human-biology. However, it is rather pointless to create specialized sub-tags if there are few questions using the main tag, at the higher hierarchical level. They will also give the question lower visibility, compared to more general and generic tags.
In this case, terminology in a sense covers etymology, but it is used rather unfrequently. If you can find e.g 10-15 question on the site where you think that the tag 'etymology' would be appropriate and useful, I see no problems with creating it (and later applying it to the relevant questions). 'Etymology' is not a biological term though, but we have other non-biological tags as well. If there aren't a number of questions where it might fit,  I don't really see the point of creating it. We have many seldomly used tags that need to be cleaned up either way.
General advice on tagging at StackExchange can be found is this meta post.

user16866: I finally decided it was useful to create the etymology tag, and I did so a few days ago. I easily added the tag to 18 posts, and I'm sure numerous more posts could (and will) get tagged with etymology.
There are now > 360 tags on Bio.SE with less questions representing them than etymology (which has been used on 19 posts).
Thanks to @fileunderwater for input.

16866: <p>I've thought about creating a new tag for etymology on a number of occasions, but have always hesitated to do so.</p>

<p>I've seen a number of questions on Bio.SE where etymology is specifically asked about (e.g., <a href="https://biology.stackexchange.com/q/42939/16866">here</a>, <a href="https://biology.stackexchange.com/questions/51322/what-is-the-origin-of-the-name-%CE%BB-phage">here</a> and <a href="https://biology.stackexchange.com/q/43110/16866">here</a>) or strongly referenced (e.g., <a href="https://biology.stackexchange.com/a/54899/16866">here</a> or <a href="https://biology.stackexchange.com/a/30469/16866">here</a>). </p>

<p>I've seen the <code>terminology</code> tag employed in some of these instances, which I find appropriate, but the true focus of the question or answer is sometimes more specifically <em>etymological</em>. </p>

<p>However, the English.SE site is already a valid place to submit etymology questions, and since etymology is more language-focused, would this tag be off-topic here?</p>

<p>My opinion is no, an etymology tag <em>would be</em> on topic and would possibly garner better response from fellow scientists (vs. those stinkin linguists :p).</p>

<p>I'm interested in other's opinions.</p>
 3624: <p>To me, tags are created ad-hoc at SE-sites when there is a need for them. The point of them is to meaningfully categorize questions, and relate questions with similar subjects. It is true that we have tags at different hierarchical levels, and e.g. many specialized tags under <a href="https://biology.stackexchange.com/questions/tagged/human-biology" class="post-tag" title="show questions tagged &#39;human-biology&#39;" rel="tag">human-biology</a>. However, it is rather pointless to create specialized sub-tags if there are few questions using the main tag, at the higher hierarchical level. They will also give the question lower visibility, compared to more general and generic tags.</p>

<p>In this case, <a href="https://biology.stackexchange.com/questions/tagged/terminology" class="post-tag" title="show questions tagged &#39;terminology&#39;" rel="tag">terminology</a> in a sense covers etymology, but it is used rather unfrequently. If you can find e.g 10-15 question on the site where you think that the tag 'etymology' would be appropriate and useful, I see no problems with creating it (and later applying it to the relevant questions). 'Etymology' is not a biological term though, but we have other non-biological tags as well. If there aren't a number of questions where it might fit,  I don't really see the point of creating it. We have many seldomly used tags that need to be cleaned up either way.</p>

<p>General advice on tagging at StackExchange can be found <a href="https://meta.stackexchange.com/questions/18878/how-do-i-correctly-tag-my-questions">is this meta post</a>.</p>
 16866: <p>I finally decided it was useful to create the <a href="https://biology.stackexchange.com/questions/tagged/etymology" class="post-tag" title="show questions tagged &#39;etymology&#39;" rel="tag">etymology</a> tag, and I did so a few days ago. I easily added the tag to 18 posts, and I'm sure numerous more posts could (and will) get tagged with <a href="https://biology.stackexchange.com/questions/tagged/etymology" class="post-tag" title="show questions tagged &#39;etymology&#39;" rel="tag">etymology</a>.</p>
<p>There are now &gt; 360 tags on Bio.SE with less questions representing them than <a href="https://biology.stackexchange.com/questions/tagged/etymology" class="post-tag" title="show questions tagged &#39;etymology&#39;" rel="tag">etymology</a> (which has been used on 19 posts).</p>
<p>Thanks to @fileunderwater for input.</p>
