user12905: I recently answered a question without providing specific sources. @MattDMo helpfully responded asking for me to update with sources, which seems appropriate, and I've added references. However, my answer received a negative vote as well, which seems strange as the answer is correct and there are no other answers on the question. 
I certainly approve of the push for proper sourcing, and think that answers with sources should receive more credit than those without. I also approve of this idea to improve popular posts that have a lot of speculation or unsourced answers. But it seems to me that there's at least some space for an appeal to authority. The question I answered is about host-pathogen interactions, and I have a PhD in immunology and have taught several courses on precisely this topic. 
It takes far more time to properly source an answer. This additional barrier, particularly on questions where I do not need to do any research to know the answer, makes me less likely to put in the effort. Again, I'm 100% on board with someone that does put in the effort to get more credit than me - I'm not saying that my authority should trump a good source. But I could use some of my own papers or course syllabi as a source for this question, so it seems silly that I should lose rep for answering it.

user5198: Appeals to authority are fairly useless on a question and answer site on the internet. For example, many people who don't know medicine will pass themselves off as doctors; it's fun to play doctor. They even get upvotes; users vote with what resonates with their mistaken beliefs. When these users' (unbeknownst to them) wrong answers are challenged in comments, they often resort to an appeal to authority. 
The SE model of requiring sources levels the playing field; appeals to authority are not respected because the user - however reasonable the answer sounds - can't show us their diplomas. 
When I first started posting here, I never posted without sources to back up my answers, even though I can make an appeal to authority. Yes, posting sources takes longer. But your familiarity with the material also makes finding sources a lot easier. 
Once in a while I do post common sense answers without sources, but I'm fully prepared for those answers to receive post notices or be deleted. After years on this site, most users familiar with me know my background and I don't get too much flack, but I don't abuse it either. Sources, not credentials, are expected on SE sites. 

user3340: I understand your sentiment but voters do not have to justify their votes. It would be ideal if they could comment about why they think your answer is insufficient so that you can improve it but not many are like that (and there is no obligation to do so). Downvoting an answer costs the voter 1 rep point. It is basically to discourage baseless downvoting of answers. Downvotes on answers are therefore likely to be less indiscriminate than on those on questions. However, I do agree that sometimes some people downvote without a proper justification or thought. It has happened to many of us not only in this site but other sites too. 
Unless there is a clear malignant serial downvoting going on, there is nothing much that would require a moderator's intervention. Moreover, moderators do not have the power to check each person's every vote. They can only look at trends.
I am sure a person with your level of knowledge would not be impeded by these minor issues. Since you said you used to teach courses, I assume you must have had students who would always be uncooperative and irritating no matter how much effort you put in to educate them. Such elements are present everywhere but there is a vast majority of good people too. So don't worry. I hope you have an overall good experience in Biology.SE. 

12905: <p>I recently <a href="https://biology.stackexchange.com/questions/54271/commensalism-with-virus-bacteria">answered a question</a> without providing specific sources. @MattDMo helpfully responded asking for me to update with sources, which seems appropriate, and I've added references. However, my answer received a negative vote as well, which seems strange as the answer is correct and there are no other answers on the question. </p>

<p>I certainly approve of the push for proper sourcing, and think that answers with sources should receive more credit than those without. I also approve of <a href="https://biology.meta.stackexchange.com/questions/3282/functionality-request-community-voting-for-answers-citations-need-banner">this idea</a> to improve popular posts that have a lot of speculation or unsourced answers. But it seems to me that there's at least some space for an appeal to authority. The question I answered is about host-pathogen interactions, and I have a PhD in immunology and have taught several courses on precisely this topic. </p>

<p>It takes far more time to properly source an answer. This additional barrier, particularly on questions where I do not need to do any research to know the answer, makes me less likely to put in the effort. Again, I'm 100% on board with someone that <em>does</em> put in the effort to get more credit than me - I'm not saying that my authority should trump a good source. But I could use some of my own papers or course syllabi as a source for this question, so it seems silly that I should lose rep for answering it.</p>
 5198: <p>Appeals to authority are fairly useless on a question and answer site on the internet. For example, many people who don't know medicine will pass themselves off as doctors; it's fun to play doctor. They even get upvotes; users vote with what resonates with their mistaken beliefs. When these users' (unbeknownst to them) wrong answers are challenged in comments, they often resort to an appeal to authority. </p>

<p>The SE model of requiring sources levels the playing field; appeals to authority are not respected because the user - however reasonable the answer sounds - can't show us their diplomas. </p>

<p>When I first started posting here, I <em>never</em> posted without sources to back up my answers, even though I can make an appeal to authority. Yes, posting sources takes longer. But your familiarity with the material also makes finding sources a lot easier. </p>

<p>Once in a while I do post common sense answers without sources, but I'm fully prepared for those answers to receive post notices or be deleted. After years on this site, most users familiar with me know my background and I don't get too much flack, but I don't abuse it either. Sources, not credentials, are expected on SE sites. </p>
 3340: <p>I understand your sentiment but voters do not have to justify their votes. It would be ideal if they could comment about why they think your answer is insufficient so that you can improve it but not many are like that (and there is no obligation to do so). Downvoting an answer costs the voter 1 rep point. It is basically to discourage baseless downvoting of answers. Downvotes on answers are therefore likely to be less indiscriminate than on those on questions. However, I do agree that sometimes some people downvote without a proper justification or thought. It has happened to many of us not only in this site but other sites too. </p>

<p>Unless there is a clear malignant serial downvoting going on, there is nothing much that would require a moderator's intervention. Moreover, moderators do not have the power to check each person's every vote. They can only look at trends.</p>

<p>I am sure a person with your level of knowledge would not be impeded by these minor issues. Since you said you used to teach courses, I assume you must have had students who would always be uncooperative and irritating no matter how much effort you put in to educate them. Such elements are present everywhere but there is a vast majority of good people too. So don't worry. I hope you have an overall good experience in Biology.SE. </p>
