The Biosphere

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8:26 AM

@YviDe I think I'm all caught up on the tiff about evolutionary biology now. I think the trouble is that vonjd thinks that the computer models are the best working theory whereas you're talking about the body of literature etc. about evolution. It seems he's taken it all rather personally, but is that the jist of it?

rg255

8:44 AM

He seems to think it's the theory that must be flawed, not the simulation. I highly doubt simulation will capture the complexity of temporal and spatial variation in demographics, selection, and genetic (co)variance which real evolution has been affected by.

James

8:58 AM

@rg255 I see. I suppose the theory can be flawed too. But incomprehensive simulations not aligning with reality don't prove or disprove the theory. They just show the simulation is incomplete. If the simulation did match reality (which is computationally ridiculous at the moment), then one would derive the theory from the simulation.

Perhaps that already got brought up, but a lot of damage control makes it hard to go back and look at. @Resonating's xkcd link seems very apt.

1 hour later…

malhar khushu

10:16 AM

I have a question, which perhaps is not suitable for the main forum (I'm new here, sorry), but can someone send me a link for a detailed procedure on how plant tissue culture can be carried out by a beginner with pretty much just basic kitchen equipment? I'm trying to grow a culture of Money plant (Epipremnum aureum) but I can't seem to find any such links. Even a message with the procedure would be greatly appreciated

4 hours later…

MattDMo

2:13 PM

@malharkhushu I'm not a plant biologist, so I don't have any direct help for you, but have you tried searching for "do it yourself" or "diy" biology? That might be a keyword that you're missing...

Satwik Pasani

2:24 PM

Q: Increasing pitch perception of the same auditory stimuli

I was trying to work up a small clip of repeating beep sounds I recorded from a mobile game. This series of sounds, when played, gave an unmistakable perception of increasing pitch with every rendition of the beep. I recorded the sound and plotted a spectrogram of the sound, and also a frequency ...

I was unsure if the above question is on-topic here. Please let me know if this is the case.

1 hour later…

MattDMo

3:24 PM

@SatwikPasani The question doesn't mention anything about biology or the biological basis of aural representation in the brain, so it's not on-topic here in its current form. Even as it stands, it's rather unclear what you're asking, especially without the actual clip(s) you're listening to.

malhar khushu

3:53 PM

@MattDMo I have, but I didn't really find anything. I'll keep looking with that specific tag, thanks!

Resonating

4:21 PM

@SatwikPasani en.wikipedia.org/wiki/Shepard_tone Is this what you're looking for?

2 hours later…

stacey

6:42 PM

Hello! I have a question and i don't know where it belongs, perhaps someone here can point me in the right direction. My question: How mang generations would it take for the world to be racially homogeneous? (Ignoring cultural and regional issues).

Satwik Pasani

7:01 PM

@Resonating Oh, thanks. But is the sound i present indeed a shepherd tone. The description in the article seems different than the one in my spectrogram.

YviDe

7:40 PM

@stacey human "race" is not a well-defined biological concept

Basically, I think that question would be unanswerable. At what level of genetic diversity would you say that there is only one "race" left.

Q: Do humans have enough biological differences to be grouped into races or subspecies?

After my online research on the subject, I learnt that, biologically speaking, many scientists believe that there is no such thing as a race. Homo sapiens as a species is only 200,000 years old, which has not allowed for any significant genetic diversification yet, and our DNA is 99.99% similar. ...

human-genetics taxonomy

Resonating

8:11 PM

@stacey Depends on what you mean by 'homogeneous', as YviDe alluded to. From the point of view of other species we're either already racially homogeneous or really super diverse and will never be homogeneous

From the point of view of rats all humans are identical already, but from the point of view of say Tasmanian devils or cheetahs humans will never approach true homogeneity.

stacey

8:38 PM

@Resonating okay. I am interested in this in a more general sense, so perhaps i should simplify the question and also choose one metric to work with: if a group of people have a whole bunch of different skin colors, after several generations there will be a lesser variation in skin color than before. Is that right? What's this area of study called? I'm curious to know if the population of earth is generally becoming more homogeneous over time or if not, why not?

rg255

-1

A: Pedigree Analysis: Problem

The case on the right is the same case as what we started off with. By matching the pair pattern on the right with the pattern of the starting pair, You can tell the answer is (A). This strategy is valid for this example, since the pattern shows that all three children have the observed trait a...

When did biology.stackexchange.com become bestguess.stackexchange.com?

Resonating

9:21 PM

@stacey The short answer is 'it depends'. People don't marry someone picked at random from the entire population of the world, they often marry/spawn with people who speak the same language as themselves. This is 'assortative mating' and it makes math about how long it takes for thigns to become completely even complicated.

There are rules for how long it takes a random mutation just by chance to 'reach fixation' and be inherited by every member of a population(it's a long time. Thousands of generations). And if new mutations of skin color/whatever occur more frequently than that there'll never ever be a uniform skin color.

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