Thread subject: Diptera.info :: Why is evolution such they?

Posted by Sara21392 on 21-11-2010 21:37
#1

We know that in Tabanidae or another families that similar to it, males fed on pollens, but females fed from the blood! Why do they have different nutritional? Why and how their evolution has been separated? But still will find each other easily? Who can advise me??
Thank you very much!

Posted by rvanderweele on 21-11-2010 21:44
#2

Females needs proteins, from blood, for their egg-production. Blood is a good source for it.

Posted by rvanderweele on 21-11-2010 22:15
#3

I do not have the time to go into detail now, 21392, but I would like to mention the dance flies. The females of many dance flies need proteins and, thus, eat other insects, while the males just visit flowers. For many species the male catches a fly and gives it to the female before copulation. It is quite a common sight in Spring to see "trio's" in nature: male, female and prey.
Dance flies developed in the middle of the Mesozoic. In the same period the first real flowers developed. You can imagine easily that from pure carnivore dance flies flies developed, which began to frequent flowers for alternative food. The females, however, often needed, nevertheless, protein from prey for laying eggs.

Posted by ChrisR on 22-11-2010 00:21
#4

Is it the case that *both* males & females drink nectar for energy - but only females drink blood for the egg proteins? Both sexes have the same mouth-parts and so they are similarly evolved ... but the females just go for an additional food source.

Posted by Sara21392 on 22-11-2010 08:11
#5

I'm so thanks from you,
but I want to understand that why do some evolutions separated between males and females, and they arenít similar, while in another, for example Hypoboscidae both males and females are parasite and fed from animals and similar samples, not just carnivorous, maybe both being evolution on nectar or etc.?? Why donít have a kind of evolutions?
even as ChrisR said, maybe some different between mouth-parts! :|
thank you very much

Posted by rvanderweele on 22-11-2010 09:55
#6

Honestly I do not understand your question. Anyway, I think a question about evolution beginning with "why" will be often impossible to answer. For evolution as such there is no reason as there is for gravitation force not reason. Evolution happens, driven by natural selection, making use of the variation within each species as so beautifully written down by Charles Darwin.

Posted by Sara21392 on 22-11-2010 10:32
#7

Okay, :| so thanks for your attention and your guide! :)

Edited by Sara21392 on 22-11-2010 10:32

Posted by ChrisR on 22-11-2010 12:11
#8

Hi Sara - I think you are trying to make the question too complicated. Some species have extremely different morphology between males and females and others are very similar. If the genes that give different morphology/behaviour give that individual a better chance of breeding than others in the same niche then it has a greater chance of passing that trait on to its offspring... and so on. We don't wonder how a male Pheasant could have evolved to be such a different colour to the females ... and in the same way some flies have different behaviour that helps their genes continue. :)

Also remember that "species" is a human concept but in almost every species the individuals are not clones, they have slightly different genes that express slightly different traits ... but they all share a common ancestor that would look virtually indistinguishable from the current generation.

Edited by ChrisR on 22-11-2010 12:15

Posted by Sara21392 on 22-11-2010 14:18
#9

I think, I knew you mean, now. definitely you're right, again thank you very much. :) :)

Posted by Larry Shone on 10-05-2011 23:54
#10

rvanderweele wrote:
I do not have the time to go into detail now, 21392, but I would like to mention the dance flies. The females of many dance flies need proteins and, thus, eat other insects, while the males just visit flowers. For many species the male catches a fly and gives it to the female before copulation. It is quite a common sight in Spring to see "trio's" in nature: male, female and prey.
Dance flies developed in the middle of the Mesozoic. In the same period the first real flowers developed. You can imagine easily that from pure carnivore dance flies flies developed, which began to frequent flowers for alternative food. The females, however, often needed, nevertheless, protein from prey for laying eggs.


Interesting Ruud, Ive not heard of Dance Flies before!