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July 4[edit]

Drone bees[edit]

Can someone help me understand the role of drone bees please? I thought that the only egg-laying bee is the Queen bee and her fertilised eggs become Worker bees and the unfertilised eggs become Drone bees. Since Drone bees fertilise the Queen bee's eggs, why aren't all resulting bees genetically identical since both sets of genes come from the queen bee (as the drone bee is from the QB's unfertliised egg)? I read that there are sometimes laying worker bees but this is only in the absence of a queen bee. Thank you — Preceding unsigned comment added by 81.91.232.122 (talk) 01:57, 4 July 2014 (UTC)[reply]

There's a good discussion here: [1]. Look for the "4.1. Genetic explanations" section. My reading is that the drones have half the queen's genes, and the queen also contributes half of her genes when mating, but these halves can include overlapping genes, and miss other genes. So, the workers each get a different set of duplicates and missing genes, making them slightly different genetically.

What I'm unclear on is how the next queen gets her genes. Is she a clone of the old queen ? If so, how is this accomplished ? StuRat (talk) 02:40, 4 July 2014 (UTC)[reply]

"My reading is that the drones have half the queen's genes"

So each of the unfertilised eggs if the queen bee are genetically distinct as they divide in half differently? And some genes are missing entirely in worker bees? Didn't realise that was possible. Do you have any more sources I can use? — Preceding unsigned comment added by 81.91.232.122 (talk) 02:55, 4 July 2014 (UTC)[reply]

Yea, you'd expect that the absence of some genes would be fatal. Perhaps they do have a high defect rate and just lay more eggs to compensate, killing off any worker that manages to hatch, but is obviously defective. They might also have many copies of critical genes on different chromosomes, to increase the likelihood that at least one will be passed on to each worker. If there's only one copy of a gene, there should be a 25% chance it will be missing, while, if there were 10 copies, each on a different chromosome, that chance drops to less than one in a million, ignoring mutations, etc. StuRat (talk) 03:16, 4 July 2014 (UTC)[reply]

I don't know what the heck you're talking about here, but there is no random gene loss. You could think of the drone as being a sperm, in the sense that it is already haploid, but it doesn't cut that down further. See haplodiploidy. Wnt (talk) 03:21, 4 July 2014 (UTC)[reply]

Oh, I see the problem. I was assuming from my reading of that site that the drones mate with their own mother (the queen), but this apparently isn't normally the case. Inbreeding, can, of course, lead to a loss of genetic diversity. StuRat (talk) 15:38, 4 July 2014 (UTC)[reply]

I think Stu is trying to get at recombination. In honey bees, when the queen lays a fertilized egg, the results are not clones, but because of haplodiploidy, they share 75% of alleles on average. When she lays an unfertilized egg, they become males, but these share only 50% of their alleles on average. In honey bees, queen determination is solely a developmental pathway, genetics have nothing to do with it. Proto-queens are just fertilized eggs layed in a special larger cell (queen cell), and fed with more royal jelly. In a laboratory setting, we can make any fertilized bee egg into a queen. Note that this is not a general rule though, in e.g. the Melipona and some other bees, there is genetic caste determination (redlink, I mean genetic control of caste_(biology), see a paper on how this work in some ants here [2]), though that is a more recent finding and less well understood. SemanticMantis (talk) 15:41, 4 July 2014 (UTC)[reply]

Lovers' lanes. Secluded, south-facing lovers' lanes, it would appear, at least in Puerto Rico, with bees commuting 500 m to 5 km to get there from hundreds of hives. The magic word is "drone congregation areas". See [3] and especially [4] for more about them. Thanks for asking this!!! Wnt (talk) 02:56, 4 July 2014 (UTC)[reply]

(Ha, this reminds me in grad school, there was a secluded road by the ag research farms called Bee Biology road. It was often used by humans as a "lovers' lane." Something about birds and bees I guess...) SemanticMantis (talk) 15:03, 4 July 2014 (UTC)[reply]

I think you've got your answers already; it's all about haplodiploidy. Also note that while technically possible, it is not the norm for a queen to mate with her own drone. See nuptial flight. Also, in honeybees, virgin queens can mate with many drones in one flight. 10-15 separate inseminations is not uncommon if I recall correctly. I also want to point out that among the bees there are very different colonial systems. In Apis mellifera, male drones are basically flying sperm that don't do much of anything other than mate and die. In some sweat bees and some solitary bees however, males life roughly as long as the female and in some cases help with provisioning offspring. Incidentally, haplodiploidy is seen as a key feature for allowing Evolution_of_eusociality in the worker castes of the eusocial hymenoptera. The idea is, sister workers share 75% of their alleles with each other, while their hypothetical offspring would only share 50% on average. Kin selection is widely accepted as an explanation for this process, but the analogous group selection is somewhat more contentious. SemanticMantis (talk) 14:59, 4 July 2014 (UTC)[reply]

Species[edit]

What's the definition of a species? 24.5.122.13 (talk) 05:28, 4 July 2014 (UTC)[reply]

See Species. HiLo48 (talk) 05:37, 4 July 2014 (UTC)[reply]

So would the spinner dolphin and the striped dolphin be considered two separate species, or two subspecies of one species, along with their hybrid the Clymene dolphin??? 24.5.122.13 (talk) 08:02, 4 July 2014 (UTC)[reply]

See Species problem. The more we study these things the more we realise that "species" is a human cultural concept, with limited application to reality. That's why cladistics is becoming the preferred method of biological classification. Rojomoke (talk) 12:42, 4 July 2014 (UTC)[reply]

It's the borderlines that cause the classification problem. This is one example. Some things called hybrids aren't really hybrids. However, you can't easily mate a dolphin with a horse, for example. Those are clearly separate species. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:41, 4 July 2014 (UTC)[reply]

See biological species concept. There are instances as in Europe where two neighboring species such as the Hooded Crow and Carrion Crow overlap in a narrow band, and hybridization occurs. The hybrids, while fertile, do not seem to fare as well as the pure species and backbreeding into the general populations is not significant enough to cause a wide transitional area of confusion among the main types. This is also common with oaks, where many species are specialized for habitat. A species specialized for humid valleys and on for dry hilltops can interbreed with fertile offspring, but the hybrids do not do as well in valleys or on mountainsides as the parent species, so the difference is maintained. The fact that there are transitional forms in no way invalidates the usefulness of the concepts as tools, when used properly. One can even clean one's earwax with a phillip's head. μηδείς (talk) 20:48, 4 July 2014 (UTC)[reply]

Job prospects[edit]

If it took 2 years longer to get a degree due to repeat years as a result of failed exams, your grades were only average and you filled the gaps with voluntary work or work in industry, how likely is that to affect your future career? — Preceding unsigned comment added by 94.10.247.171 (talk) 09:34, 4 July 2014 (UTC)[reply]

There are pro's and con's. Failed exams and repeat years isn't good - but time spent in industry and in voluntary work are a plus. I can't speak for every field - but in mine (Computer science) we probably wouldn't even ask about the reason for the extra time - probably we'd be more interested in what you did when you were "working in industry". When you get a fresh graduate with zero work experience, you always wonder how they'll adapt from easy-going college hours to a 9 to 5 job, how they'll work in a team, and how they'll cope when they are handed a project that they must complete by some deadline. Having worked in a "real job" (ideally in your field of future employment) is a huge win because it is concrete confirmation that you know what it's like to be in a 9-5 job.

You don't have to say why you took longer to get your degree on your resume and I doubt most employers would ask. But you might want to be ready with some well-thought out answers to that question. "I felt the need to dive more deeply into the subject matter" or something like that.

You also mention "your future career" - presumably beyond your first job until retirement. Again, I can only speak for my industry - but generally, your degree is what gets you your first job. Your first job is what gets your your second job and so on. The things you worked on most recently are by far more interesting than what you did 5, 10 or 20 years ago. This is especially noticeable for people with advanced degrees - masters and PhD's - for those people, it's a massive benefit for getting their first job. It matters less for their second - and after they've been out working for 20 years, recruiters may not even read that far back down their resume!

So I don't think this should affect you too badly. Certainly it mustn't affect your confidence in going into those first interviews. Make much of what you learned in your industry jobs - explain the responsibility that came with your volunteer work - how you enjoyed working in a team environment - your sense of achievement at pulling off something "real"...that kind of thing.

SteveBaker (talk) 12:10, 4 July 2014 (UTC)[reply]

Normally you'd just put your year of graduation on your resume, along with what degree or diploma you ended up with. You're not likely to be asked how long it took you to reach it. 173.228.123.145 (talk) 23:04, 4 July 2014 (UTC)[reply]

That's true - but a very late graduation might lead them to ask what you did in the years between high school and college. Gaps in a resume are usually considered significant because they can indicate period of unemployment or even prison terms. However, with the time spent working in industry and in volunteer activities, explaining away such a gap shouldn't be a problem here. SteveBaker (talk) 14:35, 6 July 2014 (UTC)[reply]

In my job hunt after graduating I customized each resume to list classes that would apply to the specific job, along with details of what subjects/projects from those classes seemed to make then a good experience. During the interview process for my current job they told me they were impressed by me putting those details into the resume, so simply listing a degree and date might not be the best idea. We request transcripts here, so bad grades would show up too. I had a rough start in college but it was clear from my transcripts that I got back on track and finished with my last few years being very strong, so they weren't concerned. Katie R (talk) 15:35, 7 July 2014 (UTC)[reply]

orang - chimp - human image origin[edit]

What is the origin of this much-parodied image on human evolution? Image:Human-evolution-man.png ---- CS Miller (talk) 12:32, 4 July 2014 (UTC)[reply]

See March of Progress. The original was drawn by Rudolph Zallinger, and first appeared in a book of the Life Nature Library series in 1965. Tevildo (talk) 13:15, 4 July 2014 (UTC)[reply]

Resolved

Thank you, Tevildo. CS Miller (talk) 14:22, 5 July 2014 (UTC)[reply]

DIS1[edit]

Dear Sirs,

Do you know what "DIS1" means? I know it is a microtubule-associated protein, but I do not know what it means, from what words it is composed. It is similar as TOG (tumor overexpressing gene), but I do not know from what words it is composed. I think that it is a TOG of the S. pombe.

Yours sincerely,

Đekić Miloš

Serbia — Preceding unsigned comment added by 109.93.106.27 (talk) 14:48, 4 July 2014 (UTC)[reply]

Possibly "defect in sister chromatid disjoining", as per this, which I found by googling "dis1". ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:06, 4 July 2014 (UTC)[reply]

Yup, I got http://www.pombase.org/spombe/result/SPCC736.14 , but don't know anything of the area to make anything of it. CS Miller (talk) 15:38, 4 July 2014 (UTC)[reply]

Sister chromatid separation is defined here. הסרפד (call me Hasirpad) 15:57, 4 July 2014 (UTC)[reply]

Is there such a thing as leaf toner?[edit]

There is a plant hormone marketed as root toner which induces the growth of roots on plant cuttings.

Is there a parallel hormone which will induce the growth of leaves on (presumably wounded) living hardwood branches that lack leaves?

I have a holly which had to have some branch ends removed. One sprouted new leaves, the other didn't.

Searches of google pretty much return only skin toner for women based on plant leaf hormone extracts.

Thanks. μηδείς (talk) 20:06, 4 July 2014 (UTC)[reply]

You'll want to consult an actual expert in person who can answer your questions more directly, but this site recommends a high nitrogen fertilizer. --Jayron32 20:42, 4 July 2014 (UTC)[reply]

I don't think there's a widely available commercial product like that.
You may be able to get your hands on some ~~auxin or~~ Gibberellic_acid, pasting some of that on the tips might help. (Oops, you want to not use auxin, that's what suppresses buds).
If you have access to any willow cuttings, (Salix spp.), you can make up a nice little batch of plant hormones in the following way: take several pencil-diameter cuttings, about 12" long (smaller or bigger is ok). Put in a small-mouth bottle to prevent evaporation, fill with water, and place in location with fairly bright indirect light. After a few weeks, you should see vigorous root growth and some bud formation. Grind up the buds and bark in the water, soak for another day, and use that to make a paste with some peat moss or leaf mulch. This paste will contain decent amounts of jasmonic acid, salycylic acid, and a few others. It can help other plants root and bud (I have not personally tested the latter).
You can also work with the plant's natural hormonal system. Apical meristems suppress the formation of other meristems, and each of those ultimately comes from stem cells, sometimes in a structure like an epicormic bud. Think of how, for many plants, a single pruning will be followed by two or more buds emerging near that tip. The the tip sends "no bud" signals to the rest of the plant, and when that signal is removed, buds form. So, you can induce bud growth on one branch by removing many bud tips/meristems from the other branch. You don't even need to remove many leaves if you don't want to, as long as the tips are taken off. This can process take some time, and may require subsequent pruning of the productive branch. If it's only been a few weeks since pruning, I'd just wait a bit more before I did much of anything.
Good luck! (post EC with Jayron, a little fertilizer couldn't hurt, but I'd personally go for a milder N level than a stronger one.) SemanticMantis (talk) 20:46, 4 July 2014 (UTC)[reply]

Thanks, guys, I actually did growth experiments in high school biochemistry and one of my undergrad majors was plant ecology.

What has happened is a holly in my father's back yard was losing half its leaves to yellow blight every year, to the point where it would soon be dead. The google solution was to remove the lower branches to improve air circulation and to remove any fallen yellow leaves in the fall. I did this, which freaked out my father, who has no idea how plants work, but who liked the ground-dragging branches. I had cut off most branches to the trunk, and had left a few at about 4 ft high as stumps one foot out from the trunk, as I would need a saw rather than the clippers I had been using.

Once he saw what I had done I was forbidden to touch the tree. I told him it was possible leaves might return on the not-fully-removed branches, just as the oak he had topped off had sprouted new branches lower down. This year the tree has three times as many leaves and no blight and one of the three stub-branches has indeed leafed. So I want to lightly scar the bark of the other two, appl something waxy, and see what happens. I might be able to get my hands on auxin, but I was hoping there was something commercially formulated and easy to use not intended as a pesticide. I am not around all the time to maintain a will compress etc. (The other problem is the oly place I'd know to get willow cuttings would be on private land.) But at least I am encouraged by the above suggestions. μηδείς (talk) 21:08, 4 July 2014 (UTC)[reply]