Actually I think ants do go through a complete metamorphosis. About 90% of the insects go through a complete metamorphosis.
Evolution of metamorphosis
- Thread starter arauca
- Start date
Actually I think ants do go through a complete metamorphosis. About 90% of the insects go through a complete metamorphosis.
It is simple explanation . It is no different " what ever will be will be "
What is you simple explanation for the Monarch butterfly , They die in the process to make a round trip from Canada to Mexico , then all the way to Canada and no death in bet ween
Are you trying to say the phenomenon is irreducibly complex? Because if you can break it down into gradual steps, which each step providing a incremental benefit, then evolution can get you there.
Huh?
Why thank you!
Migration in general is driven by lack of food as a population expands.
Stage 1: Organisms all live in an ideal climate (for them.) They expand until they start to run out of food. They start to die.
Stage 2: A few hardy individuals go north in summer when it's warm enough to do so to feed, and return when it gets too cold. They survive better than the organisms that do not, so the "wanderlust" to go north in summer becomes part of their genetic code.
Stage 3: The new requirements on the organism (better legs/wings, more fat stores due to more food eaten and longer travel times) causes rapid evolution of some traits.
Stage 4: The migratory organisms speciate from the stay-in-one-place organisms due to the significant genetic changes required, and a new migratory species is born, one with an instinct to go north in the summer, south in the winter.
You're right; an aphid would have been a better example.
William Diller Matthew (1871 - 1930) wrote a wonderful little book in 1915 called Climate and Evolution. Matthew saw climate as the primary cause or engine of evolution, and after all these years, he is still right. Since climate largely determines vegetation, and vegetation is at the base of the food chain for animals, it follows right through, including Monarch butterflies and their migration.
Rich
Rich
And vegetation determines climate, so it's a nice closed circle.
No, vegetation doesn't determine climate - grander scale phenomena, such as the earths rotation, tilt, the confuguration of the continests and of the oceanic circulation determine climate.
Climate is described by the sort of vegetation an area supports (desert, tundra, rain-forest, etc) but the vegetation is a result of the climate, not a cause of it.
Rich
Climate is described by the sort of vegetation an area supports (desert, tundra, rain-forest, etc) but the vegetation is a result of the climate, not a cause of it.
Rich
Without plants, there would be no oxygen in our atmosphere, so I think it has a significant effect.
Fraggle Rocker
Staff member
Yes, ants go through complete metamorphosis.
Spidergoat, I think I see where you are coming from, but remember, the oxygen content of the air does not differ anywhere on earth, no matter what the climate, or the elevation, or the latitude. It is the same everywhere - so oxygen, at the present time, has no determinative effect on climate.
Rich
Rich
superstring01
Moderator
Aunts. Bees. Wasps. All vespids.
The caterpillar stage didn't always used to be a free ranging insect. It used to be the "thing" that hatched from the egg and was fed by the parent (like wasps). In the case of moths and butterflies, through gradual steps in evolution, the "worm" stage increased in time and ability. It developed eyes and digestive abilities that allowed it to roam away from the nest and find it's own and scavenge for food. Whereas with flies, wasps, bees and ants never escape the next in the worm stage, in the case of butterflies and moths, the worm is a lot more independent. Eventually, though, it goes through the same pupal phase and becomes the adult.
~String
But not uncles?
It does actually have a pretty significant (though not overwhelming) effect overall. Forests create their own weather; they cool and humidify the air, resulting in higher water retention, higher transpiration rates and more rain downwind of them.
It's not.
An insect's genetic code might give an insect a tendency to migrate (eg a tendency to move toward the mid day sun when the weather is cooling).
If the insect's genetic code makes it do something advantageous, then the insect is more likely to survive and pass on its genetic code to its offspring.
If the insect's genetic code makes it do something disadvantageous, then the insect is less likely to survive and pass on its genetic code to its offspring.
So, advantageous genetic codes tend to proliferate, while disavantageous genetic codes tend to disappear.
Fraggle Rocker
Staff member
We see that happening today, right here in the northeastern United States.
For all eternity, the most important survival traits for deer were speed and agility: the ability to elude predators. But then the Americans took over the continent and killed off all the deer's predators. Predation is no longer a major threat to a deer's survival. Instead, the major threat is auto traffic. No matter how fast a deer can run, he can't outrun a car. And agility--the ability to change direction quickly--is not just not an advantage, but it's actually a disadvantage. Drivers would much prefer not to hit a deer (take my word for it, a year ago one did $7,000 damage to my truck), but if the deer runs in a zigzag pattern, he's hard to steer around.
So the deer with their time-tested survival traits are now less likely to survive and pass on their DNA to the next generation. A few deer are occasionally born with above-average intelligence. They have the ability to survey their surroundings and make reasoned decisions about it. They see the cars moving in a straight line and never going over the edge of the highway. They see drivers slowing down to avoid hitting people, dogs, cats and raccoons. They see large groups of humans--even tiny children--walking blithely across busy streets in a pattern that seems to be synchronized with the little red and green lights above the intersections. They understand that new methods are required for survival and they develop them. Those genes are passed down to the next generation.
In each generation of deer, the average speed and agility are a little less than they were before, but the average intelligence is higher. Today we see deer calmly grazing on the strip of grass next to the highway, with their antlers not quite sticking out into the traffic, confident that the cars will stay on the pavement.
More astoundingly, many people (including myself) report seeing deer standing on the curb at a crosswalk, waiting for the pedestrian signal to turn green, and then calmly walking across the street with the humans.
They have even figured out that most dogs, at some time in their ancestry, were trained to guard livestock rather than killing it. Back home in California, the deer jump over the fence into our yard at night, knowing that our dogs will do their best to protect them from the bears and cougars.
With each generation, the stupid, fast-running deer die off and the slower, smarter ones live to reproduce. The average strength and speed of the species is declining, but the average IQ is rising.
I find that EXTREMELY hard to believe. It would make more sense that the deer cross the road when the cars stop instead of them using the cross walk signal.
I suspect that the behavior might be changing, but that that is learned. I doubt that there has been much genetic change in a few generations; how long did it take to domesticate wolves into dogs - many many generations, right?