It is a parallel
case to the evolution of the birds and mammals from the reptiles.
Those that varied most in the direction of care for the egg and
the young would have the largest share in the next generation.
When we further reflect that since the Tertiary the insect world
has passed through the drastic disturbance of the climate in the
great Ice-Age, we seem to have an illuminating clue to one of the
most remarkable features of higher insect life.
The origin of the colour marks' and patterns on so many of the
higher insects, with which we may join the origin of the
stick-insects, leaf-insects, etc., is a subject of lively
controversy in science to-day. The protective value of the
appearance of insects which look almost exactly like dried twigs
or decaying leaves, and of an arrangement of the colours of the
wings of butterflies which makes them almost invisible when at
rest, is so obvious that natural selection was confidently
invoked to explain them. In other cases certain colours or marks
seemed to have a value as "warning colours," advertising the
nauseousness of their possessors to the bird, which had learned
to recognise them; in other cases these colours and marks seemed
to be borrowed by palatable species, whose unconscious "mimicry"
led to their survival; in other cases, again, the patterns and
spots were regarded as "recognition marks," by which the male
could find his mate.
Pages:
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373