It is apparent that you have gotten your misinformation about Darwin from lying creationist web sites and books.

In contrast to what most of the Christians believed at that time, Darwin was quite progressive in his views on race, and he abhorred those who mistreated and enslaved the non-white races. He never thought they were subhuman. At the time that Darwin was developing his theory of evolution, Christians justified their enslavement of blacks on both the Bible and their belief that blacks were subhuman. So don't disparage Darwin because of the lies you find in creationist web sites and books.
Here is what Darwin said about the races in his Descent:

"Although the existing races of man differ in many respects, as in colour, hair, shape of skull, proportions of the body, &c., yet if their whole organisation be taken into consideration they are found to resemble each other closely in a multitude of points. Many of these points are of so unimportant or of so singular a nature, that it is extremely improbable that they should have been independently acquired by aboriginally distinct species or races. The same remark holds good with equal or greater force with respect to the numerous points of mental similarity between the most distinct races of man. The American aborigines, Negroes and Europeans differ as much from each other in mind as any three races that can be named; yet I was incessantly struck, whilst living with the Fuegians on board the Beagle, with the many little traits of character, shewing how similar their minds were to ours; and so it was with a full-blooded n e g r o with whom I happened once to be intimate."

Does that sound like someone who believed that blacks are inferior?

Carefully read what he subsequently went on to say"

"The great break in the organic chain between man and his nearest allies, which cannot be bridged over by any extinct or living species, has often been advanced as a grave objection to the belief that man is descended from some lower form; but this objection will not appear of much weight to those who, from general reasons, believe in the general principle of evolution. Breaks often occur in all parts of the series, some being wide, sharp and defined, others less so in various degrees; as between the orang and its nearest allies—between the Tarsius and the other Lemuridæ—between the elephant, and in a more striking manner between the Ornithorhynchus or Echidna, and all other mammals. But these breaks depend merely on the number of related forms which have become extinct. At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate, and replace, the savage races throughout the world. At the same time the anthropomorphous apes, as Professor Schaaffhausen has remarked, will no doubt be exterminated. The break between man and his nearest allies will then be wider, for it will intervene between man in a more civilised state, as we may hope, even than the Caucasian, and some ape as low as a baboon, instead of as now between the n e g r o or Australian and the gorilla."

Considering that Darwin had said the similarities in intellect between whites and other races were insignificant, his remark about the separation between the N e g r o or Australian and the gorilla was certainly referring to the primitive way they were living in the wild in contrast to that of those who lived in a "civilized state," rather than to any perceived similarity to apes.

And he was not advocating the extermination of the N e g r o e s. He was making an observation of what could happen as a result the the Caucasian's actions toward them.

Again, since at that time most Christians believed that N e g r o e s were subhuman or intellectually deficient, you have no business singling out Darwin by attributing him with your erroneously perceived racism.

The following shows Darwin's attitude towards the enslavement of n e g r o e s in contrast with the Christian norm of the time.

"While strolling about the town Darwin was disgusted at the sight of black slaves, and upon returning to the Beagle he got into a big quarrel with Capt. FitzRoy about the ethics of treating humans as property. FitzRoy [who was a devout Christian] flew into a temper and forbid Darwin to share his dinner table with him ever again. After a short cooling off period Capt. FitzRoy apologized to Darwin and his privilege to dine with him was restored.

" 'We had several quarrels; for when out of temper he [FitzRoy] was utterly unreasonable. For instance, early in the voyage at Bahia in Brazil he defended and praised slavery, which I abominated, and told me that he just visited a great slave-owner, who had called up many of his slaves and asked them whether they were happy, and whether they wished to be free, and all answered 'No.' I then asked him, perhaps with a sneer, whether he thought that the answers of slaves in the presence of their master was worth anything. This made him excessively angry ...'"
-- Charles Darwin [11]
http://www.aboutdarwin.com/voyage/voyage…

Now aren't you ashamed of yourself for defaming Darwin by passing on creationist lies? He was a better man than most Christians of the time.

I submit that you know nothing of either evolution or Darwin except the lies you find in creationist web sites and books.

Added:

"It is quite obvious that Darwin was not commenting on cultural differences, but supposed biological difference that he claimed to observe (that supposedly blacks were biologically primitive as compared to whites)."

Reread my excerpts from his works. I quote them again since you apparently failed to grasp what he said.

"Although the existing races of man differ in many respects, as in colour, hair, shape of skull, proportions of the body, &c., yet if their whole organisation be taken into consideration they are found to resemble each other closely in a multitude of points. Many of these points are of so unimportant or of so singular a nature, that it is extremely improbable that they should have been independently acquired by aboriginally distinct species or races. The same remark holds good with equal or greater force with respect to the numerous points of mental similarity between the most distinct races of man. The American aborigines, Negroes and Europeans differ as much from each other in mind as any three races that can be named; yet I was incessantly struck, whilst living with the Fuegians on board the Beagle, with the many little traits of character, shewing how similar their minds were to ours; and so it was with a full-blooded n e g r o with whom I happened once to be intimate."

Does that sound like someone who believed that blacks are inferior?

You have absolutely no basis in saying that Darwin held that blacks were biologically primitive as compared to whites. All you are doing is trying to smear evolutionary theory by smearing Darwin.

That, coupled with Darwin's hatred of slavery in contrast with the Christian norm of the time makes your whole argument pitiful and disgusting.

Added:

"Yes. Darwin is quoted saying that whites are the most evolved, while the other races are less evolved. He said that blacks were only slightly evolved over gorillas. Darwin predicted that the other races would soon "be exterminated" leaving a larger evolutionary gap between the white races and the gorillas. These words of Darwin are quite racist and evil."

It is apparent that your mind has been raped by your having read creationist anti-evolution propaganda. Darwin was not condoning the future extermination of blacks. He was making a prediction based on his observations of what happened when the Christian colonialists of his day conquered the uncivilized peoples.

Darwin: "Although the existing races of man differ in many respects, as in colour, hair, shape of skull, proportions of the body, &c., yet if their whole organisation be taken into consideration they are found to resemble each other closely in a multitude of points. Many of these points are of so unimportant or of so singular a nature...The American aborigines, Negroes and Europeans differ as much from each other in mind as any three races that can be named; yet I was incessantly struck, whilst living with the Fuegians on board the Beagle, with the many little traits of character, shewing how similar their minds were to ours; and so it was with a full-blooded n e g r o with whom I happened once to be intimate."

Does that sound like Darwin thought blacks are only slightly evolved over gorillas?

I challenge you to provide a single quote from Darwin's works saying that.

Your mind has been so twisted by the anti-evolution propaganda you have been reading you cannot even think straight.