Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 66 (9078 total)
114 online now:
Minnemooseus (Adminnemooseus), Phat (2 members, 112 visitors)
Newest Member: harveyspecter
Post Volume: Total: 895,087 Year: 6,199/6,534 Month: 392/650 Week: 162/278 Day: 2/28 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Winter Project
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


(4)
Message 16 of 59 (891688)
02-08-2022 9:14 PM
Reply to: Message 15 by dronestar
02-08-2022 1:03 PM


Re: More Dragonfly movement . . . and its sight acumen
And as a designer, I can confidently state humans only need about . . . three, maybe four shades of oranges in life.

That's probably true about how many shades of orange we need but we can see way more than that. I remember reading about tests where subjects looked at specific wavelengths of light, but I can't remember how many angstroms the average person see the difference between. I can detect the differences between all 256 shades of each color in an 8-bit digital image as well as all 256 shades of gray. In 16bit color tones blend seamlessly. And by tone I mean brightness or darkness.

What we think dragonflies experience with the additional opsins is colors separated by wavelength, not just brightness. So we have 3 primary colors and they have 30 primary colors.

The eyes are also broken up into different zones with different diameter or aperture and different focal lengths. There is a hover fly, Syritta pipiens, the male has a group of forward looking ommatidia that only fire nerve impulses if they detect the color and flight pattern of a female which it then imitates precisely. I suspect something similar in dragonflies. They can identify males and females of their own species, but also other species based on field observations, but sometimes they make mistakes and misidentify males of other species as their own.

A book I can highly recommend about vision is, Eyes to See, the Astonishing Variety of Vision in Nature, by Michael Land.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


This message is a reply to:
 Message 15 by dronestar, posted 02-08-2022 1:03 PM dronestar has replied

Replies to this message:
 Message 17 by dronestar, posted 02-09-2022 6:32 PM Tanypteryx has not replied
 Message 21 by dronestar, posted 02-10-2022 2:35 PM Tanypteryx has replied

  
dronestar
Member
Posts: 1396
From: usa
Joined: 11-19-2008


(1)
Message 17 of 59 (891707)
02-09-2022 6:32 PM
Reply to: Message 16 by Tanypteryx
02-08-2022 9:14 PM


Re: More Dragonfly movement . . . and its sight acumen

The idea of MILLIONS of shades of orange to be offered, . . . contrasted with being the very LEAST favorite colour, . . . strikes me as being hilariously ironic.

However, . . . maybe dragonflies like the colour orange. Who am I to tell some random dragonfly what its preferred colour is? The nerve.

The eyes are also broken up into different zones with different diameter or aperture and different focal lengths.

Wow.

only fire nerve impulses if they detect the color and flight pattern of a female which it then imitates precisely."

Amazing. Reminds me of advanced cameras that can detect a face or subject at a designated depth and then snaps the shutter automatically.

Thanks for the recommendation "Eyes to See, the Astonishing Variety of Vision in Nature". Yeah, it sounds like something I would very much enjoy. The book is offered on Amazon for less than $18, and with a hardcover to boot.


This message is a reply to:
 Message 16 by Tanypteryx, posted 02-08-2022 9:14 PM Tanypteryx has not replied

  
ringo
Member
Posts: 19745
From: frozen wasteland
Joined: 03-23-2005
Member Rating: 2.9


(2)
Message 18 of 59 (891744)
02-10-2022 12:01 PM
Reply to: Message 15 by dronestar
02-08-2022 1:03 PM


Re: More Dragonfly movement . . . and its sight acumen
dronestar writes:

And as a designer, I can confidently state humans only need about . . . three, maybe four shades of oranges in life.


As a friend of mine used to say, the only things that should ever be orange are pumpkins and oranges.

dronestar writes:

A 10-bit HDTV can show a range of 1.07 billion possible colors.


And there's still nothing on.

"I call that bold talk for a one-eyed fat man!"
-- Lucky Ned Pepper

This message is a reply to:
 Message 15 by dronestar, posted 02-08-2022 1:03 PM dronestar has replied

Replies to this message:
 Message 20 by dronestar, posted 02-10-2022 1:55 PM ringo has seen this message but not replied

  
xongsmith
Member
Posts: 2240
From: massachusetts US
Joined: 01-01-2009
Member Rating: 3.0


(4)
Message 19 of 59 (891748)
02-10-2022 12:43 PM


Did someone say "orange"?

A poet who burst on our times
With a wardrobe of lemons and limes
Went looking for four eng-
ineers dressed in orange
To fix up the worst of his rhymes.

"I'm the Grim Reaper now, Mitch. Step aside."

- xongsmith, 5.7d


  
dronestar
Member
Posts: 1396
From: usa
Joined: 11-19-2008


(3)
Message 20 of 59 (891754)
02-10-2022 1:55 PM
Reply to: Message 18 by ringo
02-10-2022 12:01 PM


Orange you glad somebody posted this . . .
Hi Ringo,

As a friend of mine used to say, the only things that should ever be orange are pumpkins and oranges.

Just for good measure, . . . can we also declare presidents should never be orange?


This message is a reply to:
 Message 18 by ringo, posted 02-10-2022 12:01 PM ringo has seen this message but not replied

  
dronestar
Member
Posts: 1396
From: usa
Joined: 11-19-2008


Message 21 of 59 (891756)
02-10-2022 2:35 PM
Reply to: Message 16 by Tanypteryx
02-08-2022 9:14 PM


Re: More Dragonfly movement . . . and its sight acumen
So we have 3 primary colors and they have 30 primary colors.

While I am being silly posting about the color orange, . . .

. . . do we know what colors the dragonflies opsins detect? Are they weighted toward a particular hue? You mentioned ultra-violet. Can there be many shades of ultra-violet that multiple opsins detect? A bee is attracted to the shape of a flower's ultra-violet pattern. But I presume dragonflies do not seek out flowers for the same reason, if at all, correct?

Dragonflies having so many opsins is 'bugging' me. Nature, what the hell? Why?

I may be compelled to buy the book you recommended sooner than later. I wish the book reviewers would have written that the illustrations inside were more polished, my best style for learning is visual.


This message is a reply to:
 Message 16 by Tanypteryx, posted 02-08-2022 9:14 PM Tanypteryx has replied

Replies to this message:
 Message 22 by Tanypteryx, posted 02-10-2022 2:54 PM dronestar has replied
 Message 24 by Tanypteryx, posted 02-10-2022 3:39 PM dronestar has not replied

  
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


Message 22 of 59 (891757)
02-10-2022 2:54 PM
Reply to: Message 21 by dronestar
02-10-2022 2:35 PM


Re: More Dragonfly movement . . . and its sight acumen
While I am being silly posting about the color orange, . . .

I have a question about orange, is the word for orange the color and orange the fruit the same word in other/all languages like it is in English?


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


This message is a reply to:
 Message 21 by dronestar, posted 02-10-2022 2:35 PM dronestar has replied

Replies to this message:
 Message 23 by dronestar, posted 02-10-2022 3:03 PM Tanypteryx has not replied

  
dronestar
Member
Posts: 1396
From: usa
Joined: 11-19-2008


Message 23 of 59 (891758)
02-10-2022 3:03 PM
Reply to: Message 22 by Tanypteryx
02-10-2022 2:54 PM


Re: More Dragonfly movement . . . and its sight acumen
orange the color and orange the fruit

I'm embarrassed to say I only speak English. When traveling, I learn a dozen or so phrases in other languages as I need them, then the words are completely forgotten after I return home. In my case, attempting to speak Chinese was worse than not trying to speak Chinese.

I HIGHLY regret not taking any languages in school or college.


This message is a reply to:
 Message 22 by Tanypteryx, posted 02-10-2022 2:54 PM Tanypteryx has not replied

  
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


Message 24 of 59 (891759)
02-10-2022 3:39 PM
Reply to: Message 21 by dronestar
02-10-2022 2:35 PM


Re: More Dragonfly movement . . . and its sight acumen
I may be compelled to buy the book you recommended sooner than later. I wish the book reviewers would have written that the illustrations inside were more polished, my best style for learning is visual.

It helped me think about vision in new ways. Another book I have learned a lot from recently is, Complex Worlds from Simpler Nervous Systems, by Frederick R. Prete, 2004. I ordered it used from Amazon for $4 and got a brand new hard cover copy.

. . . do we know what colors the dragonflies opsins detect? Are they weighted toward a particular hue? You mentioned ultra-violet. Can there be many shades of ultra-violet that multiple opsins detect? A bee is attracted to the shape of a flower's ultra-violet pattern. But I presume dragonflies do not seek out flowers for the same reason, if at all, correct?

Dragonflies having so many opsins is 'bugging' me. Nature, what the hell? Why?

I'm looking for answers to all these questions and a bunch more. We need a lot more students out there in the field making observations, especially in the tropics.

Some species of dragonflies may visit flowers to prey on insects visiting the flower for pollen or nectar, but I have not studied that behavior. It is well documented that many of the helicopter damselflies in the neotropics visit spider webs to pick insect prey from them and many other species of damsels glean insects, like aphids, from plants.

Many odonata wings have markings of all sorts of colors and patterns and some wings reflect UV patterns that are invisible to humans. I have had some truly incredible encounters with both dragonflies and damselflies in the neotropics with metallic colored wings. Damselflies in the family Polythoridae have species that mimic butterflies and that have all sorts of bright colored patterns, with lots of oranges. One species, Cora terminalis, has wings that look clear if viewed flat, but if angled just a bit the whole wing flashed bright silvery blue. It was truly amazing watching two males displaying to each other while spirally up in a sunbeam penetrating the forest canopy in Bolivia.

Or the tiny dragonfly, Zenithoptera lanei, that has metallic blue on the upper surface and shiny black on the undersides of the wings. Both sexes signal each other with various wings held down or folded closed over the back. Sometimes they even have the front wings down and the hind wings closed.

Edited by Tanypteryx, : No reason given.

Edited by Tanypteryx, : spelling

Edited by Tanypteryx, : No reason given.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


This message is a reply to:
 Message 21 by dronestar, posted 02-10-2022 2:35 PM dronestar has not replied

Replies to this message:
 Message 25 by Theodoric, posted 02-11-2022 10:22 AM Tanypteryx has replied

  
Theodoric
Member
Posts: 7412
From: Northwest, WI, USA
Joined: 08-15-2005
Member Rating: 2.7


Message 25 of 59 (891789)
02-11-2022 10:22 AM
Reply to: Message 24 by Tanypteryx
02-10-2022 3:39 PM


Puerto Rico
We are spending a week in Puerto Rico in March. Hopefully, I will be able to get away from the beach and spend some time in the area of our family ancestral home. That is in the western highlands in the area of Utuado. We may make a run to El Yunque rainforest also, but when we were there a few years ago most of it was still closed due to hurricane damage. Do you know anything about dragonflies and damselflies in Puerto Rico?
Any pointers of where to look?

What can be asserted without evidence can also be dismissed without evidence. -Christopher Hitchens

Facts don't lie or have an agenda. Facts are just facts

"God did it" is not an argument. It is an excuse for intellectual laziness.

If your viewpoint has merits and facts to back it up why would you have to lie?


This message is a reply to:
 Message 24 by Tanypteryx, posted 02-10-2022 3:39 PM Tanypteryx has replied

Replies to this message:
 Message 26 by Tanypteryx, posted 02-11-2022 10:39 AM Theodoric has not replied

  
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


Message 26 of 59 (891790)
02-11-2022 10:39 AM
Reply to: Message 25 by Theodoric
02-11-2022 10:22 AM


Re: Puerto Rico
I have not worked with Caribbean dragonflies, but there are some real beauties. Any aquatic habitat should have dragonflies, but my favorite tropical habitats are mountain streams.

Dragonflies and damselflies (Odonata) from Puerto Rico: a checklist with notes on distribution and habitat


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


This message is a reply to:
 Message 25 by Theodoric, posted 02-11-2022 10:22 AM Theodoric has not replied

  
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


(4)
Message 27 of 59 (892141)
02-26-2022 10:22 PM


Matallic Wings in the Sun
Yesterday, after a session reprocessing some photos from a trip to Ecuador in 2013 I posted one of them on my Facebook page. It was a shot of a little tropical dragonfly, Zenithoptera lanei, that has amazing wings that look metallic blue on the dorsal (upper) surface and black or dark metallic red on the ventral surface.

The males of this species use the positioning of the wings to signal conspecific males in pretty complex displays. My photo was of a display position that we, my traveling pals, have never seen any other species perform, with the front wings held doin front of the dragonfly and the hind wings held closed over the back showing the dark underside.

This morning there was a link posted in the comments of my Facebook post to a newly published paper about the same species and proposing and testing an hypothesis for an additional function for the bright iridescent color of the wings, camouflage. The link was posted by one of the authors in Brazil.

Camouflage by counter-brightness: the blue wings ofMorpho dragonfliesZenithoptera lanei(Anisoptera:Libellulidae) match the water background free access.

This is a fascinating study, but I haven't finished reading it yet. I just got kind of excited about it because it has a bunch of interesting info about dragonfly eyesight too, and we had talked about it recently here.

I photographed and and studied Z. lanei in Ecuador in 2009 and 2013 and in Costa Rica in 2015.


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


  
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


Message 28 of 59 (892364)
03-06-2022 11:54 AM


Thanks Covid
I don't know how much businesses closing because of the pandemic has affected every day life of most people, but for biologists, primarily entomologists, the closing of one business will have a huge negative impact on field research research for years.

BioQuip was the primary North American supplier of all the equipment used in the field and lab, from vials to nets, and they are closing up shop. A year ago we started hearing that they were struggling to stay afloat, and many of the people I know started placing orders and stockpiling consumables and critical equipment, but in January they announced they were closing for good. They sold the best nets and bought the best net manufacturer, so now both are gone, fuck!


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


Replies to this message:
 Message 29 by AZPaul3, posted 03-06-2022 5:41 PM Tanypteryx has not replied

  
AZPaul3
Member
Posts: 6834
From: Phoenix
Joined: 11-06-2006
Member Rating: 3.4


Message 29 of 59 (892403)
03-06-2022 5:41 PM
Reply to: Message 28 by Tanypteryx
03-06-2022 11:54 AM


Re: Thanks Covid
Ouch!

The bug guys I knew in school were quite adept at improvising equipment because of their penchant to chase creepy-crawlies into dark corners on the spur of the moment. But your professional stuff and the professional results you get from it? Ouch!


Eschew obfuscation. Habituate elucidation.

This message is a reply to:
 Message 28 by Tanypteryx, posted 03-06-2022 11:54 AM Tanypteryx has not replied

  
Tanypteryx
Member
Posts: 3424
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 4.1


(2)
Message 30 of 59 (893932)
04-23-2022 5:53 PM


Getting Ready
I'm wasting time while I have my imaging system shooting focus stacks of dragonfly eggs (collected last September in Wisconsin) that have just come out of the refrigerator after a long winter's nap. They should recommence development (after 5 months of diapause) in the next few days. Several different clutches need to warm up to room temp before i can shoot them otherwise moisture collects on slides and coverslips etc.

This is my 44th winter rearing at least one species of dragonfly eggs that have a diapause in their normal embryonic development. The first 20 years I was using a simple compound microscope with my 35mm SLR shooting color slides of the eggs. Digital cameras and high resolving power, aberration free optics gave me unprecedented views inside living eggs and changed my life forever.


Stop Tzar Vladimir the Condemned!

What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy

The reason that we have the scientific method is because common sense isn't reliable. -- Taq


  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.1
Innovative software from Qwixotic © 2022