Why does the extant males species of the primate family Hominidae have mammilla's?
91408
Mammillae are standard issue and develop before the sex chromosomes x and y kick in.\n\nAnd that's why men have nipples.
410905
Yes, they both come from the Human family. They are second cousins to Chimp and Zees and distantly related to many other primates.
716183
What might have caused the branching that founded the new forms of robust australopithecines (Paranthropus) and Homo? What caused the extinction, around the same time (between 2-3 million years ago) of genus Australopithecus? Finally, what might have caused the extinction of Paranthropus about 1 million years ago?\n\nNo certainty in answering these questions. But the environmental conditions at the time might hold some clues. Increased environmental variability, starting about 6 million years ago and continuing through time and resulting in a series of newly emerging and diverse habitats, may have initially promoted different adaptations among hominid populations, as seen in the branching that gave rise to the robust hominids and to Homo.\n\nAnd if the degree of the environmental fluctuations continued to increase, this may have put such pressure on the hominid adaptive responses that those groups less able to cope eventually became extinct. Unable to survive well enough to perpetuate themselves in the face of decreasing resources (e.g., Paranthropus, who were specialized vegetarians) these now-extinct hominids were possibly out-competed for space and resources by the better adapted hominids, a phenomenon known as competitive exclusion.\n\nIn this case, only the adaptive response that included an increase in brain size, with its concomitant increase in ability to understand and manipulate the environment, proved successful in the long run.
96736
They are individuals that have both male and female reproductive parts.  They are called hermaphrodites.
81500
This question makes no sense.  Homo sapien doesn't even refer to sex at all but the genus of species Homo sapiens (Humans)(Latin for "wise man"): they are bipedal primates of the superfamily Hominoidea, along with the other apes—chimpanzees, gorillas, orangutans, and gibbons.
466168
because males MAY use them as stimulation receptors, they aren't ruled out by evolution\nso infact that are used, just not like females use them (think about it, if a male has nipples and uses them this way, then he would be able to spread his charateristic to more females thereby increasing the popularity and favorability of the trait)\nas for the question of why they there in the first place...\nits one of those characteristics that are kept when the baby is developing in the womb
297158
Genus Humanus, and the Homo Sapien designation for modern man...but there are others, check the link below.
644132
I am curious as to who the "they" is that you are referring to...\n\nCurrently there are two theories regarding the origins of modern humans, "Multiregional" and "Out of Africa".\n\nThe Africa origin theory is pretty well supported with fossil, artifact (tools, etc.) and DNA evidence, the multiregional origin theory has less evidence (currently) but this should not completely discount it.\n\nThe first link has more on the differences between these, and examines the evidence in more detail. The next two provide some examples of the competitiveness of this debate.\n\nKeep in mind that proponents of either theory are well aware of human evolutionary history and understand that current evidence suggests the first upright primates DID come from Africa (see last link)
30459
wow, you are asking this in biology and getting all these fruitcake religious answers? Most likely, the first sexually reproductive organisms where something akin to hermaphrodites- both "sexes" within the same organism or colony, it wasn't until later that individual organisms were expressly male or female, so, in truth, "man" and "women" really male and female, evolved concurrently.
161827
A - because they are the same species and therfore have the same number of chromosomes, which means they can breed together.  homosapiens and chimpanzees are quite closly related but have different number of chromosomes so they cannot mate.  if they did manage to mate the offspring would be infertile, a bit like the liger, which is the offspring of a lion and a tiger.  chimps and humans have approx 97% of the same genes!!
5138
Exactly. Humans did not evolve from primates. The theory of evolution is full of holes.
1102060
Yes.The are called hermorphodites.They are born with both male and female sex organs.
86011
Males also have the hormone estrogen. Estrogen menlarges breast size. Women have more of it, so they have bigger breasts. They also have luteniezing hormone which produces milk for mammary glans after giving birth. Men do not have that. Women displaying male qualities like beards have an excess of testoserone and androgen
416191
They are two VERY different creatures and the genetic research they are doing has recently shown that the X chromosome in men and the X chormosome in women is very differnt much to their surprise!\n\nIt is almost like we are two different species genetically.
902693
The answer is an unequivocal "NO"!  For starters, lets look at the rationale against such a proposition.  \n\nEvolutionarily speaking, sexual reproduction is important in that it has the advantage over asexual reproduction of mixing genetic combinations available to the offspring.  In the human species, this sexual reproduction requires both a male and a female.  What accompanies these facts is that the female is genetically prepared to carry a child once pregnant.  Such features which are vital to this are a uterus, the hormones estrogen and progesterone which prepare the uterus for implantation, ovaries to supply eggs, and a vaginal canal for birthing.  All of these features are primary sex characteristics that can only develop in the ABSENCE of a "Y" chromosome.  Evolutionarily, then, it is to the advantage of the species that phenotypic distinctions between males and females exist, and these physical differences preclude the possibility of the male of the species to be capable of pregnancy.  On this logic alone, men can not become pregnant.  But there is more evidence.\n\nSecondly, think about this:  humans and our ancestors have had millions of years to develop such features, if it were in fact possible, but it has NOT happened.  Why not?  Because there is no SELECTIVE ADVANTAGE for the human species of men acquiring these features and abilities. \n\nThird, there ARE cases of individuals that receive extra SEX chromosomes (look up Klinefelters and Turner' syndrome, for example) where individuals are born with XXY and XYY.  XXY individuals, as a rule, are infertile and can not produce children.  XYY individuals are fertile but are phenotypically male and do not develop uteruses and other features necessary to become impregnated.  So even in the cases of chromosal conditions that might perhaps favor male pregnancy, we do not observe males with the ability to be so.\n\nSo, IF a male had eggs they could not be fertilized because there is no way that the design of a male can receive semen into the genetalia.  But even if this were possible, there would be no place for the fertilized eggs to implant.  And if even they could implant, they couldnt grow because estrogen and progesterone are not present in high enough quantities in males to prepare the uterus (high levels of these hormones would have produced a female during development of the fetus).  This all boils down to the simple and obvious reality that males can not become pregnant.\n\nSomeone might perhaps argue, well it would be possible if certain mutations occurred.  This also is false.  Why?  Because evolution is a process that moves down a one-way street.  While such capability is present in lower organisms, higher animals are too specialized to be capable of such a transformation.  Even if all the proper sets of supposed mutations had amassed in one organism, that organism would either (one) not survive and be spontaneously aborted in utero, or (two) be born as an infertile individual.  Again, only lower animals with less well specialized sexual reproductive organs are capable of self-fertilization and "pregnancy" (flowering plants, for example, are capable of this).\n\nFinally, a genotypic male could undergo gender reassignment and become female, but a uterus and other "equipment" would have to be transplanted and various hormones taken.  I imagine, in theory, that this individual would be capable of becoming pregnant but in this scenario "he" is no longer "male".  \n\nGood question, but the answer is NO!
568942
Based on fossil, genetic, and molecular evidence, we have a long train of ancestors in our history.  Modern humans and other primates, such as monkeys, have a common ancestor that lived about 25 million years ago, and our ancestor would probably *not* be considered a "monkey."  Before that were early mammals, and before that mammal-like reptiles, the sauropsids. Before that were early reptiles, and amphibians.  And yes, before that, about 440 million years ago, one of our ancestors was a fish.  So you are correct.
170001
baboon, barbary ape, capuchin monkey, celebes maque,colobus monkey, Douroucouli, Guenon, Howler monkey, langur, Macaque, mandrill, mangabey, marmoset, proboscis monkey, Rhesus Monkey, Saki (monkey), Spider monkey, Squirrel monkey, Tamarin, Titi, Uakari, Woolly monkey..............(list goes on forever....)