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To pick one specific aspect: Male pseudoscorpions smell the number of competitor males that have copulated with a female and adjust by progressively decreasing

To pick one specific aspect: Male pseudoscorpions smell the number of competitor males that have copulated with a female and adjust by progressively decreasing sperm allocation as the number of different male olfactory cues increases from zero to three. How in the world was this determined? It's presented so neatly, and I certainly believe it, but it's fascinating to think of the procedures that must've been taken to verify such a claim. You'd need a scorpion sperm counter, perhaps, and I'm not sure Amazon sells one.

positr0n 6y ago
Probably some grad student pipets a precise quantity of scorpian semen onto a slide, perhaps with a dye to aid the process, and manually counts the number of sperm with a microscope. Human sperm tests are done using a similar procedure depending on what you are looking for.
- sillysaurusx 6y ago
  Fascinating; apparently you can perform a sperm count test on yourself with nothing more than a microscope: https://www.hellomotherhood.com/article/94302-read-clearblue-pregnancy-tests/ https://www.hellomotherhood.com/article/94302-read-clearblue... and a spreadsheet: https://web.archive.org/web/20070224203309/http://www.fertilityformen.com/download/sar.xls https://web.archive.org/web/20070224203309/http://www.fertil... There's a high-quality video here: https://www.youtube.com/watch?v=T9_XkaXCXqc&ab_channel=AdvancedFertilityCenterofChicago https://www.youtube.com/watch?v=T9_XkaXCXqc&ab_channel=Advan... I'm just surprised it's theoretically possible to do it yourself. Tests are upwards of $100.
  - jdc 6y ago
    Hey, this is great info. Any machine learning engineers have a bunch of spare time on their hands?
    - sillysaurusx 6y ago
      Interesting line of thinking. I guess you could pipe a microscope's video feed into a YOLO model and do a count. The hard part would be making it cost effective. Legacy (YC S19) seems to be capturing this market: https://www.givelegacy.com/ https://www.givelegacy.com/ $200 is still a hefty price though.
    - tzs 6y ago
      There are automated sperm sample analyzers already, that give sperm concentration, motility (broken down by rapid, slow, and non), morphology, velocity, and more. Here's a promotional video from 2008 from a maker of such devices [1]. Here's a 2015 video from them showing a newer model [2]. I'm not sure how they actually work. Given the age it probably isn't machine learning. The same company also sells a home test kit, under the name Yo, which might use machine learning [3]. It uses your smart phone camera. There is also a PC/Mac version that looks like it includes its own camera. $69.95 for either kit, $45.95 for refills for the consumables for 2 tests, $89.95 for 4 tests. [1] https://www.youtube.com/watch?v=krakvOT-7xI https://www.youtube.com/watch?v=krakvOT-7xI [2] https://www.youtube.com/watch?v=ukIns4rPgHw https://www.youtube.com/watch?v=ukIns4rPgHw [3] https://www.yospermtest.com/how-it-works/ https://www.yospermtest.com/how-it-works/
  - darkerside 6y ago
    Not that surprising. Doing my own is one thing. For counting someone else's sperm, $100 seems pretty low.
claxc 6y ago
These experiments have so many variables that the outcome is sometimes hard to believe (see the section about rats): http://calteches.library.caltech.edu/51/2/CargoCult.htm http://calteches.library.caltech.edu/51/2/CargoCult.htm Maybe the don't "adjust", but it is a fear reaction because of the imagined proximity of other males, which kind of distracts from the act ... How they measured it? Perhaps a fake female with a reservoir, which would introduce even more variables.
_Microft 6y ago
I'm reasonably sure that this is the paper in question if someone cares enough to actually want to read it: "Discriminating Males and Unpredictable Females: Males Bias Sperm Allocation in Favor of Virgin Females", doi:10.1111/j.1439-0310.2011.01928.x
godelzilla 6y ago
For me it's more fascinating to think about how "science" articles regularly overstate and exaggerate weak data.

positr0n 6y ago

Probably some grad student pipets a precise quantity of scorpian semen onto a slide, perhaps with a dye to aid the process, and manually counts the number of sperm with a microscope. Human sperm tests are done using a similar procedure depending on what you are looking for.

sillysaurusx 6y ago
Fascinating; apparently you can perform a sperm count test on yourself with nothing more than a microscope: https://www.hellomotherhood.com/article/94302-read-clearblue-pregnancy-tests/ https://www.hellomotherhood.com/article/94302-read-clearblue... and a spreadsheet: https://web.archive.org/web/20070224203309/http://www.fertilityformen.com/download/sar.xls https://web.archive.org/web/20070224203309/http://www.fertil... There's a high-quality video here: https://www.youtube.com/watch?v=T9_XkaXCXqc&ab_channel=AdvancedFertilityCenterofChicago https://www.youtube.com/watch?v=T9_XkaXCXqc&ab_channel=Advan... I'm just surprised it's theoretically possible to do it yourself. Tests are upwards of $100.
- jdc 6y ago
  Hey, this is great info. Any machine learning engineers have a bunch of spare time on their hands?
  - sillysaurusx 6y ago
    Interesting line of thinking. I guess you could pipe a microscope's video feed into a YOLO model and do a count. The hard part would be making it cost effective. Legacy (YC S19) seems to be capturing this market: https://www.givelegacy.com/ https://www.givelegacy.com/ $200 is still a hefty price though.
  - tzs 6y ago
    There are automated sperm sample analyzers already, that give sperm concentration, motility (broken down by rapid, slow, and non), morphology, velocity, and more. Here's a promotional video from 2008 from a maker of such devices [1]. Here's a 2015 video from them showing a newer model [2]. I'm not sure how they actually work. Given the age it probably isn't machine learning. The same company also sells a home test kit, under the name Yo, which might use machine learning [3]. It uses your smart phone camera. There is also a PC/Mac version that looks like it includes its own camera. $69.95 for either kit, $45.95 for refills for the consumables for 2 tests, $89.95 for 4 tests. [1] https://www.youtube.com/watch?v=krakvOT-7xI https://www.youtube.com/watch?v=krakvOT-7xI [2] https://www.youtube.com/watch?v=ukIns4rPgHw https://www.youtube.com/watch?v=ukIns4rPgHw [3] https://www.yospermtest.com/how-it-works/ https://www.yospermtest.com/how-it-works/
- darkerside 6y ago
  Not that surprising. Doing my own is one thing. For counting someone else's sperm, $100 seems pretty low.

claxc 6y ago

These experiments have so many variables that the outcome is sometimes hard to believe (see the section about rats): http://calteches.library.caltech.edu/51/2/CargoCult.htm http://calteches.library.caltech.edu/51/2/CargoCult.htm Maybe the don't "adjust", but it is a fear reaction because of the imagined proximity of other males, which kind of distracts from the act ... How they measured it? Perhaps a fake female with a reservoir, which would introduce even more variables.

_Microft 6y ago

I'm reasonably sure that this is the paper in question if someone cares enough to actually want to read it: "Discriminating Males and Unpredictable Females: Males Bias Sperm Allocation in Favor of Virgin Females", doi:10.1111/j.1439-0310.2011.01928.x

godelzilla 6y ago

For me it's more fascinating to think about how "science" articles regularly overstate and exaggerate weak data.