before making some stupid, or rather, ignorant comments, you might want to look up definitions.
They also showed some positive assortative mating.”
Positively assortative for what? fly sweat? fried sperm?
possitive assortative mating means that organisms tend to mate with other organisms that are similar to them. why am I attracted to white, blond, blue eyed girls? gee, I don't know, maybe because I'm a white, blond haired, blue eyed guy.
a rarer form of mating is negative assortative mating. that would be me, a white, wanting to mate with black chicks.
here's another misstatement you made.
where a species was actually granted
you'll notice the title to the experiment you dissect is "Sexual Isolation as a Byproduct of Adaptation to Environmental Conditions in Drosophila melanogaster"
not exactly proclaiming speciation to begin with.
let's stick with this current experiment and your
many errors
so you screwed up what possitive assortative mating means. what else went wrong?
The first thing I would suspect is a genetic defect
actually no. the organisms of population A were not able to cross with members of population B. Plus, its not across the board. They found some reproductive isolation between the two groups. A can mate with A, B with B.
The reason I can state this is because of"These things were not observed in populations which were separated but raised under the same conditions". so A was split into two groups. these two groups of A
had no difficulty whatsoever with mating with each other.
The only place any form of assortative mating was found was when group A and group B met for mating purposes.
you're statement of
Really? There are so many errors in logic, and experimental flaws, in this one little abstract, that I conclude this to be USELESS INFORMATION
is quite wrong.
you misunderstood what was written.
next experiment you talk about, how many errors can we find?
We would need more information as to the genders of parents when hybrids were produced
umm, you do realize there are only two genders in the fruit fly, right? male and female. what more do you need?
it seems to suggest that a continually hybridized culture was being taken closer and closer to one of the original strains to which the original female did not belong, and then BAM! The whole population dies off. Yup, that’s the hallmark of a new species just waiting to unfold.
wrong. you have two strains of the same species, one from Llanos, one from Orinocan. When crossed initially, the hybrids were fertile. Somewhere along the line, something happened, so that by 1963 a cross between the Llanos line and the Orinocan line produced fertile hybrids in one sex--female. that means you have two populations that can no longer viably mix.
I immediately recognize the probability of genetic birth defects
most of these offspring will die well before the chance to mate. And considering the number of offspring they have, there will be plenty of D. melanogaster's that are genetically viable. You also have to account for the mutation rate, which, when dealing with large numbers of offspring, will override genetic birth defects wiping out the species.
now for your commentary of:
And, nowhere did I see an instance where a species was actually granted for a sexually reproducing creature
new species listed on the page:
O. lamarckiana ( a plant, therefore capable of sexual reproduction) has a split= O. gigas
Primula verticillata and P. floribunda crosses eventually led to=P. kewensis
T. dubius and T. porrifoliuscrossed =T. miscellus (also has the advantage of occuring in nature)
Raphanus sativus and Brassica oleracea led to a new genus, after a while=genus Raphanobrassica
G. pubescens crossed with G. speciosa = G. tetrahit
Gottlieb (1973) documented the speciation of Stephanomeira malheurensis (5.2.1)
5.2.3 is quite confusing, but suggests that very few changes are necessary in genes for reproductive isolation. new species also observed.
now for animals:
5.3.1 (one you posted)
5.3.5 this one being sympatric. read this "After 25 generations of this mating tests showed reproductive isolation between the two strains. Habitat specialization was also produced.
They next repeated the experiment without the penalty against habitat switching. The result was the same -- reproductive isolation was produced. They argued that a switching penalty is not necessary to produce reproductive isolation"
please note that all you need for speciation is reproductive isolation.
5.7 take a look at the chart. you now have two species where there was one.
5.8 this one is just wierd.
these are the most clear examples of speciation amongst sexually reproducing organisms in the list.
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