we are the product of a process that started 3.8 billion years ago , with the origin of life , being just one of the astonishing different forms which emerged with the evolutionary process . but how different are we from the other living beings ? we differ from the other primates by a series of characteristics , and a list of selected anatomical and physiological traits is given in table 1 . it is impossible to single out any one of them as the most important , since the evolutionary factors act over the organism as a whole . but we are the only vertebrate species with a bipedal gait and erect posture ; birds are bipedal , but their backbone is generally horizontal , and the kangaroo bipedalism does not involve erect posture . one of the most important human characteristic is our brain , that is three times larger than that of the chimpanzee and much more complex , with the cerebral cortex proportionally much larger than those of other apes . other important morphological traits involved a modification of the vocal tract , which made possible the origin of language in a much more sophisticated form than the rudiments found in other species ; opposable and larger thumbs ( important for tool manipulation ) , and a series of characteristics related to reproduction and life history that were related to the evolution of social life . the type of social organization evolved in our species was of fundamental importance for its survival and evolutionary history ; and a distinctive process , made possible by a series of traits related to cognition , was culture , whose complexity is many orders of magnitude higher than related phenomena found in other organisms . human behavior can be defined as the set of attitudes and reactions of an individual or group in response to a stimulus . multiple factors influence behavior , which could be classified in three categories : genetic , ontogenetic and cultural . genes supply the material bases for hormones and other proteins which would be primarily responsible for the individual norm of reaction . but the life history of each person is also important , at all stages of her / his life , involving the physical and sociocultural environments . the relationships among these variables are non - linear , being influenced by intergenerational construction / deconstruction factors , as well as feedback processes . our biological constitution favors wide flexibility rather than fixed , immutable , patterns of behavior responses ( fuentes , 2009 ) . it is generally held that a fundamental distinction of our species in relation to all other animals is the complexity of our culture . but the term is of difficult definition , and some colleagues even maintain that there are as many culture concepts as there are anthropologists ! ( 2010 ) define it as  information that is capable of affecting individuals behavior , which they acquire from other individuals through teaching , imitation , and other forms of social learning  . from this perspective it can be said that the spreading of this ability can be to a certain extent independent of the environment . foley and lahr ( 2011 ) adopt this same concept , but proposed that the different types of culture were and are the outcome of the way in which kin - based human communities reproduce over generations , fissioning ; and that the rate of this fissioning is strongly influenced by ecological and geographical factors . the dialectic relationships between biology and culture followed an interesting evolution . in the 19 and beginning of the 20 centuries there was a consensus that genetic factors influenced in a marked way the capacity of acquiring and developing culture . afterwards , by the influence , for instance , of franz boas ( 18581942 ) , an opposing change happened , and all sociocultural patterns were supposed to be completely free of biological influence . in recent years a reaction to these manichean views occurred , with emphasis on interpretive approaches postulating an interaction between these two sets of elements . 2010 ) list and characterize ten mathematical models of gene - culture co - evolution . only relatively recently models were developed at the cultural side to interpret and quantify phenomena of this type , but now it is possible to compare in a more specific way these two types of processes . the main difference between the two processes is that the rate of change is much faster in cultural as compared to genetic evolution . this is because the genetic transmission most often occurs in a vertical ( parent - offspring ) way , while the cultural one can also happen vertically , but in addition can be transmitted horizontally ( between persons of the same generation ) or obliquely ( teacher - pupil ) . methods to identify how the transmission occurred in specific ways were presented by borgerhoff mulder et al . a special type of transmission is that related to the intergenerational inheritance of material goods , a problem that is indirectly related to the unequal wealth and class formation in human societies . this question has been extensively considered in a set of contributions ( one introduction , five articles , and the answers of their authors to 10 comments ) published in current anthropology , volume 51 ( bowles et al . , 2010 ; whole material , p. 7126 ) . hewlett et al . ( 2002 ) considered genetic , geographical , cultural in general and linguistic traits , with the objective of understanding africa s cultural variability . three models were examined : ( a ) cultural diffusion ; ( b ) local adaptations ; and ( c ) demic diffusion . individual seme analyses indicated different associations in relation to the models , but those related to kinship proved to be quite conserved , and their distribution to follow mainly the demic diffusion model . recently methods have been developed to detect statistical signatures in the human genome of recent , strong positive selection , namely , genes that have been favored by natural selection over the past 100 thousand years . such signals include high - frequency alleles in linkage disequilibrium , unusually long haplotypes of low diversity , and an excess of rare variants . as a result of these efforts about two thousand genes had been identified as having such selective sweeps , and many of their distributions could have been influenced by cultural factors . they are related to diet , immunity , climate adaptation , visible characteristics , and cognition . some of these factors are interwoven ; for instance , the variability in skin color genes could be related both to climate adaptation ( exposure to ultraviolet radiation ) and sexual selection ( assortative mating ) . the identification of selective factors may in some cases be difficult due to the fact that these pressures may vary in direction and intensity along time . the enhancer of gene expression hacns1 , with a 546-base pair sequence , is highly conserved in all terrestrial vertebrate genomes . however , there was an accumulation of 16 human specific changes since the human - chimpanzee split , which occurred six million years ago . alternative explanations for this rupture of the conservation would be ( a ) positive selection ; or ( b ) biased gene conversion , and the discussions held concerning these two possibilities had not at the time considered population data . we ( hnemeier et al . , 2010 ) studied 83 south amerindians , 11 eskimos , 35 europeans , 37 bantu and non - bantu sub - saharan speakers , and 28 brazilian admixed subjects and found no variation in this dna region . similar lack of variability was found in four africans , five europeans or euro - derived persons , two asians , one paleo - eskimo , and one neandertal sequences , whose whole genomes were publicly available . these results favor the interpretation of past positive and present conservative selection , as would be expected in a region which influences homo - specific traits as important as opposable thumbs , manual dexterity , and bipedal walking . another locus which showed peculiarities in terms of selection is paired box gene 9 ( pax9 ) . its coding sequence is composed of four exons , in a total of 2.1 thousand base pairs . exon 2 is responsible for sequence - specific contacts with dna , and , together with exon 4 , shows an impressive absence of nucleotide sequence variation among 44 mammal species . in contrast , exon 3 shows a different picture . we ( paixo - crtes et al . , 2011 ) recently sequenced its 138 base pairs ( bp ) and its 5 and 3 flanking regions ( with 232 bp and 220 bp respectively ) in 138 amerindians , 44 eskimos , 14 japanese , 15 europeans , and 47 africans . nine mutations were scored in the coding sequence and six in its flanking regions ; four of them are new south amerindian singletons . an interesting polymorphism ( ala 240 pro ) occurs in this exon 3 . the derived allele c(pro ) occurs everywhere in the world , with frequencies of 20% in africans , 30% in europeans , and 45% in asians ( chinese and japanese ) . in south amerindians there is considerable variation among the 15 tribes tested , from zero to 40% ( paixo - crtes et al . , 2011 ) . the extreme conservation of four of its exons point to purifying selection , but its exon 3 variability opens an evolutionary window for positive selection . specifically the ala 240 pro polymorphism seems to be associated with third molar agenesis , especially so in africa . a reduced number of molars may be evolutionarily advantageous ; with the dramatic lifestyle and diet changes which occurred with the discovery of fire and the development of cooking devices , mastigatory strength became less important for survival , and dental arches have been reduced over hominid evolution . as a consequence third molars became frequently impacted or malpositioned , leading to periodontal diseases ( caries , cysts , tumors ) . any genetic change that would lead to their absence would be favored , and this seems to be the case for the c(pro ) mutation ( pereira et al . , 2006 ) . the dopamine receptor d4 ( drd4 ) gene is one of the most variable ones in the human genome and has an expressed variable number of tandem repeats ( vntr ) of 48 base pairs . the 7r allele was associated with behavior variables such as novelty - seeking , impulsivity and hyperactivity . a recent investigation by our group ( tovo - rodrigues et al . , 2010 ) about the distribution of these alleles in south amerindians ( 18 populations , 568 persons ) displayed higher 7r frequencies in populations with a recent past of hunter - gathering ( average : 58% ) as compared to agriculturalists ( 48% ) . exploratory behaviors would be adaptive in nomad societies , because they allowed for more successful exploitation of resources . conversely , in agriculturalist sedentary societies , novelty - seeking and exploratory behaviors would have social costs , because these populations developed intensive methods for land use in a given settled environment , which favor permanence . we are confronted , therefore , with another example in which biological factors would influence a behavioral trait . of course , the decision to migrate and explore new environments depends on many other factors , which should also be considered in an interdisciplinary context . by now it should be clear that the answer to the first part of the title s question is affirmative . we are changing , and the evolutionary factors involved are heavily influenced by the respective cultural and socioeconomic environments , which provide a unique set of opportunities . there is no doubt that if the present economic and political model will persist , there is a real probability that the pessimistic view will prevail . the easiest way for the oppressed of escaping oppressors is the search for mystical or mythical beliefs (  my present life is worthless , but i will be rewarded in god s kingdom  ) . this behavior , coupled with resentment and lack of understanding of science s potential role for the improvement of life conditions , can lead to a nebulous world , in which extreme misery will necessarily coexist with scandalous wealth . against this tendency a consistent effort for the equalization of opportunities between individuals and nations should be made . science has contributed to a substantial betterment of the world s life conditions ( examples : increase in life expectancy , better food quantity and quality , protection against environmental stresses , higher interaction between individuals and groups , prevention and cure of many diseases ) . but to reach the conditions indicated by the optimistic view science this is not enough . a vigorous political action in favor of the presently excluded and discriminated is equally necessary .
the questions of the title have been considered in several ways . 
 first , indications of the traits which make us humans were considered 
 . then the behavior and culture concepts were examined , and the biology and culture interactions discussed , with an emphasis on the similarities and differences between the genetic and cultural transmissions . 
 next diverse types of selective pressures were reviewed , and finally pessimistic and optimistic views of our future contrasted . 
 vigorous action against acts which lead to exclusion and discriminatory policies against human subjects is needed .