Call it a shock discovery: DNA research has revealed two entirely new species of electric eel in the Amazon basin, including one capable of delivering a record-breaking jolt. The findings are evidence, researchers say, of the incredible diversity in the Amazon rainforest -- much of it still...
There we go with the thread necromancy again, . I was a bit surprised to find I had actually commented in this before. Makes me wonder what it would be like to see a whole archive of all my posts since the boards came back in 2002.
I wonder how the fires affect the critters in the water.
In August 2012, Douglas Bastos, then a graduate student at Brazil’s Instituto Nacional de Pesquisas da Amazônia, was exploring a remote waterway in the Amazon rainforest when he came across a small lake teeming with electric eels. Electric eels, which despite their name are actually a type of...
So, there's a bit of an error in there. Look at the butterfly - "...in addition to seeing two colors we don't have names for, butterflies can see a massive spectrum of colors our brains aren't even capable of processing."
That is, as described, extremely misleading, bordering on false.
Humans have Red, Green, and Blue cones, and broadband receptors we call rods. The eyes of the Japanese yellow swallowtail (Papilio xuthus) contain ultraviolet, violet, blue, green, red and broad-band receptors (which are not quite the same as our rods).
Now, we have to get into what it means to "see" a color. As the graphic shows, we don't have a receptor for yellow, but we can see yellow. We don't have specific receptors for violet, but we CAN see violet, even though the butterfly has a receptor for it we do not.
For no animal are the color receptors really all that specific. Our cones that we say "see green" have peak sensitivity in Green, and then sensitivity trailing off up and down the spectrum from there. So, when light hits our eyes, our rods go "There is light!". From each cone we get a different signal strength - like blue fires 50%, Green fires 75%, Red fired 25% - and our brain interprets that combination signal as a color.
This, is by the way, how mixing paint works. We do not have specific receptors for "purple". Violet light hits our retina, and generates a mix of signal strengths, and we perceive "purple". But, any mixture of light that generates the same relative responses will also be seen as purple. It isn't that, if we mix red and blue paint, the result suddenly reflects violet light. It just reflects light that generates a signal very much like violet light does!
Now, with butterflies, we might note that with more different receptors, they should have greater perception of fine differences in hue. And that may be so. But, it may also be that since they have itty bitty brains, they don't have as much processing power as we do, and they may make up for that lack with having different receptors - yielding color differentiation either a bit better or worse than ours, in the end. It is difficult to tell what the butterfly brain actually perceives.
So, there's a bit of an error in there. Look at the butterfly - "...in addition to seeing two colors we don't have names for, butterflies can see a massive spectrum of colors our brains aren't even capable of processing."
That is, as described, extremely misleading, bordering on false.
Humans have Red, Green, and Blue cones, and broadband receptors we call rods. The eyes of the Japanese yellow swallowtail (Papilio xuthus) contain ultraviolet, violet, blue, green, red and broad-band receptors (which are not quite the same as our rods).
Now, we have to get into what it means to "see" a color. As the graphic shows, we don't have a receptor for yellow, but we can see yellow. We don't have specific receptors for violet, but we CAN see violet, even though the butterfly has a receptor for it we do not.
For no animal are the color receptors really all that specific. Our cones that we say "see green" have peak sensitivity in Green, and then sensitivity trailing off up and down the spectrum from there. So, when light hits our eyes, our rods go "There is light!". From each cone we get a different signal strength - like blue fires 50%, Green fires 75%, Red fired 25% - and our brain interprets that combination signal as a color.
This, is by the way, how mixing paint works. We do not have specific receptors for "purple". Violet light hits our retina, and generates a mix of signal strengths, and we perceive "purple". But, any mixture of light that generates the same relative responses will also be seen as purple. It isn't that, if we mix red and blue paint, the result suddenly reflects violet light. It just reflects light that generates a signal very much like violet light does!
Now, with butterflies, we might note that with more different receptors, they should have greater perception of fine differences in hue. And that may be so. But, it may also be that since they have itty bitty brains, they don't have as much processing power as we do, and they may make up for that lack with having different receptors - yielding color differentiation either a bit better or worse than ours, in the end. It is difficult to tell what the butterfly brain actually perceives.
Yeah, someone in the original thread from whence that image was plucked made most of the same observations. But Imgur isn’t the most copy/paste friendly site out there. And my innate laziness trumped my willingness to offer the correction you did.
One thing about purple: it's likely that only primates see a form of purple that fades smoothly from blue to red. Because our blue sense also reacts to red to some level.
news.yahoo.com
. I was a bit surprised to find I had actually commented in this before. Makes me wonder what it would be like to see a whole archive of all my posts since the boards came back in 2002.
