Cats in Crete and China, and evolution


Cretan Cat - photo by Kenny Darrell

A cat Kenny Darrell photographed in Crete -- notice each eye is a different color.

Darwin wondered about the genetic reasons behind white cats being blind deaf (though, of course, he didn’t call it “genetics” then).  Evolution in action:  White cats today usually can see hear.

Kenny found this cat in Crete, and got a good shot of its eyes, each of a different color — though of course, as soon as the focus was set, the cat leaned forward for a pet.

Kenny’s in China right now.  I wonder if China has cats and dogs on the streets like Crete?

Below the fold:  Darwin on white cats.

Darwin, in Origin of Species, p. 29:

Many laws regulate variation, some few of which can be dimly seen, and will hereafter be briefly discussed. I will here only allude to what may be called correlated variation. Important changes in the embryo or larva will probably entail changes in the mature animal. In monstrosities, the correlations between quite distinct parts are very curious; and many instances are given in Isidore Geoff roy St.Hilaire’s great work on this subject. Breeders believe that long limbs are almost always accompanied by an elongated head. Some instances of correlation are quite whimsical: thus cats which are entirely white and have blue eyes are generally deaf ; but it has been lately stated by Mr. Tait that this is confined to the males. Colour and constitutional peculiarities go together, of which many remarkable cases could be given amongst animals and plants. From facts collected by Heusinger, it appears that white sheep and pigs are injured by certain plants, whilst dark-coloured individuals escape : Professor Wyman has recently communicated to me a good illustration of this fact; on asking some farmers in Virginia how it was that all their pigs were black, they informed him that the pigs ate the paint-root (Lachnanthes), which colored their bones pink, and which caused the hoofs of all but the black varieties to drop off; and one of the “crackers” (i.e. Virginia squatters) added, “we select the black members of a litter for raising, as they alone have a good chance of living.” Hairless dogs have imperfect teeth; long-haired and coarse-haired animals are apt to have, as is asserted, long or many horns ; pigeons with feathered feet have skin between their outer toes ; pigeons with short beaks have small feet, and those with long beaks large feet. Hence if man goes on selecting, and thus augmenting, any peculiarity, he will almost certainly modify unintentionally other parts of the structure, owing to the mysterious laws of correlation.

Many laws regulate variation, some few of which can be
dimly seen, and will hereafter be briefly discussed. I will
here only allude to what may be called correlated variation.
Important changes in the embryo or larva will probably en-
tail changes in the mature animal. In monstrosities, the
correlations between quite distinct parts are very curious;
and many instances are given in Isidore Geoff roy St.
Hilaire's great work on this subject. Breeders believe that
long limbs are almost always accompanied by an elongated
head. Some instances of correlation are quite whimsical :
thus cats which are entirely white and have blue eyes are
generally deaf ; but it has been lately stated by Mr. Tait that
this is confined to the males. Colour and constitutional pecu- 

30 ORIGIN OF SPECIES 

liarities go together, of which many remarkable cases could
be given amongst animals and plants. From facts collected
by Heusinger, it appears that white sheep and pigs are in-
jured by certain plants, whilst dark-coloured individuals es-
cape : Professor Wyman has recently communicated to me
a good illustration of this fact; on asking some farmers in
Virginia how it was that all their pigs were black, they in-
formed him that the pigs ate the paint-root (Lachnanthes),
which colored their bones pink, and which caused the hoofs
of all but the black varieties to drop off; and one of the
"crackers" (i.e. Virginia squatters) added, "we select the
black members of a litter for raising, as they alone have a
good chance of living.'' Hairless dogs have imperfect teeth ;
long-haired and coarse-haired animals are apt to have, as is
asserted, long or many horns ; pigeons with feathered feet
have skin between their outer toes ; pigeons with short beaks
have small feet, and those with long beaks large feet. Hence
if man goes on selecting, and thus augmenting, any pecu-
liarity, he will almost certainly modify unintentionally other
parts of the structure, owing to the mysterious laws of cor-
relation.

4 Responses to Cats in Crete and China, and evolution

  1. James Hanley says:

    On correlation of traits, I remember reading a few years back that Russian scientists had managed to breed for docile silver fox in only 40 generations, but in doing so had ended up with foxes with mottled coats. Apparently dogs (canis familiaris) are more likely to have mottled coats than wolves (canis lupus). So at least some biologists now think there is some genetic correlation between docility and mottled coats.

    The 40 generations also seems to set a sort of lower boundary on the possible rate of the domestication of dogs.

    Like

  2. White cats aren’t always deaf, but they’re more likely to be than other cats; if they have one blue eye, they’re more likely to be deaf on that side. White cats are significantly more likely than other cats to be heterochromic; the whole issue is tied to coat colouration genetics, and while it is a fascinating field of study, it rather makes my head spin.

    Like

  3. Ed Darrell says:

    That’s an image for a movie: A cat wading through a puddle, in the rain, to take refuge in a storm sewer.

    Save that image for when you direct the remake of “Breakfast at Tiffany’s.”

    Like

  4. Kenny says:

    Yes, yes there are cats on the street here. In fact, today I saw a white cat wading his way through a puddle to take shelter from the rain in a storm drain.

    Like

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