Why haven't more species evolved to develop a bond with other species to help both species survive, like Dogs and Humans?
As others have pointed out, there is no shortage of symbiotic relationships on Earth. The bond between humans and dogs is, however, arguably unique. I would guess that the reason we don’t see more relationships like the human/dog relationship is because two species of apex predators living in the same area will be in competition with one another. It generally wouldn’t be in the best interest of individuals of either species to cooperate with one another; their survival often depends on their ability to outcompete one another for the available resources. I suspect that in order to develop an inter-species relationship like the one between humans and dogs, at least one of the species would need to be able to observe the behavior of the other (e.g. “some of those wolves are less aggressive/less fearful/more curious than the others”) and imagine the possible advantages of a different relationship between the two species. That takes a great deal of imagination and intelligence. Both species would almost certainly need to be highly social, which isn’t all that common in large predators. I’m sure it takes a species with highly complex social structure to be able to recognize and respond to social cues from another species. Intelligent, imaginative predators living in large social groups aren’t all that common. It’s actually pretty amazing that the relationship between humans and dogs exists.
Why haven't humans diversified other species the same way they have diversified dogs?
Dogs are one of the earliest animals domesticated by humans and have been bred for multiple purposes throughout history, rather than just being bred for meat or just being bred as only a hunting partner.
Why haven’t dog races become species already?
The primary difference between a Chihuahua and a Great Dane is a single gene mutation.http://www.theguardian.com/scien...There are three total genes that account for the majority of differences in all dog size variants.http://www.psmag.com/books-and-c...You can still cross breed the two dogs without unusual difficulty, so long as the larger dog is the mother. Take internet breeds with a grain of salt but --
Why aren't the different breeds of dogs different species?
Ok, I misunderstood your question. You're asking why dog breeds are still able to reproduce with each other and haven't split into species, even though we have "forced evolution on them". Dog breeds haven't had a speciation event for several reasons. First, evolution usually takes a very long time (at least for complex multicellular organisms like mammals). If we took two breeds and separated them for hundreds of thousands or millions of years, they would certainly be incapable of interbreeding. Man has domesticated dogs for, what, a few thousand years? There simply hasn't been enough time for mutations to accumulate to an extent where breeds become species. But you are right, we are driving evolution through artificial selection and accelerating this process, however, dog breeds are selected based on physical and behavioral traits, while divergence of two species requires "deeper" changes to genes that are more crucial to survival than coat color or retrieving instinct. Also, you answer your own question: you understand that speciation requires reproductive isolation, but you also imply that dog breeds are able to (and DO) mate with each other. Since there is still a lot of gene shuffling going on, this maintains enough similarities to ensure compatibility among breeds, thereby preventing divergence of species.
My best friend is having sex with a dog!!!!! please help?
thanks for yalls help im going to tell her parents and my uncle is a doctor should i tell him to so he can help/tell her the possible risks and she is 14 shes one years older then me we were talking about sex and how i wanted to wait till im married to have it and then she told me she needs to tell me a secret.
Why haven't humans significantly extended the lifespans of dogs in the same way we've extended our own lifespans?
We haven't changed our lifespan biologically, we're just better at avoiding death. Average lifespan used to be a lot lower, meaning that many people died young while some lived into elderly years. Today, we have much safer living environments and modern medicine that allow most people to live into old age. In other words, we now reach our bodies' full aging potential instead of dying early.We do the same for animals that live as pets, or in zoo captivity. For a comparison to humans, look at gorillas. Their average lifespan in the wild is 35 years, but in zoos, they usually live to be well over 50. But you asked about dogs. Yes, this applies to dogs, too. Doggy lifespan varies significantly from one breed to another, but 10-15 years is a general average. Domestic dogs don't live in the wild, but lets' look at some of their wild relatives:Wolves. 7 years in the wild, 17 years in captivity.Dingos. 5 years in the wild, 15 years in captivity.Coyotes. 7 years in the wild, 15 years in captivity.Foxes. 4 years in the wild, 15 years in captivity/as pet.Do you see the pattern?So, we have indeed extended the lifespans of dogs in the same way that we have extended our own.