How do sexually specialized species evolve into other sexually specialized species?

Question

By "sexually specialized species," I mean: 2 and only 2 sexes, and unlike aphids, all offspring must have a male and female parent.

Think how far back on h.sapiens' evolutionary tree one must trace back before finding a species with multiple modes of reproduction (3 or even more genders, and/or self-fertilizing capability.)

How do all its (many) sexually specialized evolutionary descendants, in h.sapiens' lineage, generate new species, when offspring require 2 parents having complementary sets of chromosomes?

Do two complementarily genetically mutated individuals, a male and a female from EACH of the interval species, have to a) be at the same place and the same time b) successfully mate?

People with chromosomal abnormalities can't have kids, NOT because there aren't individuals with the same chromosomal abnormality--some are common--but because each individual with chromosomal abnormality is rendered infertile. Why then are 1st male/female of each new species fertile?

H.Peterman: Domestic dogs (Canis lupus familiaris) are subspecies of the Gray Wolf (Canis lupus) species. A breed is not a species.

http://en.wikipedia.org/wiki/Gray_Wolf

SAN, Maybe, don't we all have one or two passionately opinions that we might have to admit, in time, after reasoned dialogue, to being completely wrong about?

Feel free to speak up and disagree with me. I don't do ad hominems. Unless I'm clowning around with someone, and they KNOW I'm clowning around with them, and frankly, I don't know you well enough to deliver an ad hominem to you.

Oh, San, I realize you asked me a question. Good. And I promise to try to accept your answer to the questions I ask back graciously. Why do I assume that speciation occurs in one generation? Members of two different species can't breed, right? So when a species (OK, after thousands of generations) gives rise to an individual that is so genetically different from its parents that he becomes the first in a new species, he cannot breed with anyone from his parents' species, right? Then who DOES he/she mate with, to continue the new species?

Please forgive my ignorance rjkardo. I got the idea that people with chromosomal abnormalities cannot breed because until tonight, the only c.a.'s I knew about were 1)incompatible with life 2)incompatible with reproduction, Down and Turner's Syndromes.

I just found out about Klinefelter's Syndrome, which apparently 1 in 500 men has. About 5% of them can father children.

Here is the blog I just discovered by ChloePrice, a man who has this Syndrome.

http://blog.360.yahoo.com/blog-PMLerugyc6ppA9HkcwFsRUAhk_pYqYGhagHL1vjwQsHE

So I will have to refine my statement to: MOST chromosomal abnormalities prevent fertility or even survival to the neonatal stage.

HPeter and Rjkardo: Do you know whether or not a grey wolf and a chihuaha, if forced, could produce offspring. If so, grey wolves and chihuahas are breeds of the same species, and nobody who domesticated wolves was creating new species.

All sorts of wild things going on:
http://www.lairweb.org.n

oops. Here's the WHOLE address.
http://www.lairweb.org.nz/tiger/cabbits.html

Yes I am confused SAN, or I wouldn't have asked the question. But you're not helping.

Maybe it would help me if you ran your explanation along the "number of chromosomes" line. No matter HOW gradual the development of a new species is, no matter HOW long the interval in which the developing species is reproductively compatible with the old species, there IS a point at which interbreeding becomes impossible. How is this point determined? Doesn't it have something to do with chromosome numbers of the new species being unequal to those of the base species? Does the species "gradually" change its characteristic number of chromosomes by having one of them gradually atrophy, or by gradually growing an extra chromosome? Doesn't a process like this seem to be working against the pretty heavy headwind of the lethality of chromosomal changes?

Answer 1

Your question indicates you are trying to make a point. My answer is to ask you a question. Why do you presume speciation occurs in one generation? Strand some reps on an island, come back in a hundred generations, and you probably still have the same species. Come back in a thousand generations, and maybe not.


Edit: Just checked in and found your comments. You are clearly confused on the process of speciation. When we drop the species reps off on a desert island, they will gradually begin adapting to their new environment, and gradually changing their physical and gene structures as they do. Eventually, the drift can become so great that members of this island could no longer successfully breed with their distant brethren back on the mainland. At that point, we can proclaim a new species. However, there is NO sudden "eureka we have a new species" birth. Offspring will continuously be compatible with the other locals. Strong mutations which cause sudden and radical alterations are almost always lethal. Progress is a tippy-toe process even in the punctuated evolution format.

Answer 2

You seem to have some incorrect views on how reproduction can work, specifically dealing with chromosomes. People with chromosomal abnormalities can have kids. I don't know where you got the idea that they cannot.

We are not all identical. The 'match up' does not have to be perfect.
That being understood, it is easy to see how sexual specifications can change, and how speciation can occur.

Your comment about wolves and dogs is incorrect.
Dogs may be a subspecies of wolves, that does not make them a different breed, but a subspecies. You seem to now understand the difference.

Answer 3

This question is a very good one. Anyone who has even a basic understanding of reproduction knows that not only are there many physical parts required for sexual reproduction, there are also many hormones and interdependence on other systems that are involved. So in order for sexual reproduction to "evolve", both genders would have had to simultaneously mutate their very different,meet complimentary parts, along with a whole slew of hormones that signal the body to release the hormones necessary for such reproduction. Hard to believe that all,of those mutations could have all happened at the same time and yet work so beautifully together. Am I the only one who sees a problem here for evolutionists?

Answer 4

Do you mean how did humans come up with all the breeds of dogs starting from wolves?