Seminar 4 2011 Discussion Page Challenge 1

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Challenge Question 1


Human evolution can be characterised by both biological and cultural change over time. Compare and contrast biological and cultural evolution in terms of transmittance of information between generations, selection, and fitness.

I.Mouraviev.2011 Student- Ivan, Dilworth School, Friday 3rd June 2010. Hi, here is my response to the discussion question. Enjoyed writing this, it's an interesting topic. Feedback is appreciated, as this is my first post on the Wiki! Thanks


The biological and cultural evolutions of the human are inextricably linked. Various behaviours, habits, customs and the like are, through observation and subsequent learning, horizontally transmitted within and across social groupings. Learning and horizontal transmission can underpin the vertical transmission seen in biological evolution in the sense that the adoption of certain behaviours or customs can increase one’s survival rate and therefore chances of successfully passing genes on to the next generation. So, though it is clear that biological and cultural evolution are both of great importance to the evolution of humans as a whole, they operate in significantly different ways. Specifically, the main differences lie in the transmission of information between generations, selection and fitness.


In cultural evolution, the transmission of information is generally horizontal. This means the learning and adoption of behaviours, habits and customs need not be over several generations – it can simply occur within the same social grouping, regardless of generation difference. The most successful variables should in theory be those for which society has the most preference. But, not all variables most preferred by society are necessarily useful or beneficial. The capacity of individuals (especially humans) to learn maladaptive behaviours cannot be ruled out. Certainly, in today’s modern society it is not uncommon for social groups (particularly among youth) to adopt behavioural patterns which have no apparent benefit to the group or the individuals in it.

So, the variables selected by society to be continually passed on, taught and learned are the most preferred. This selection leads to the concept of cultural fitness. Logically, one would assume that cultural fitness is defined as following the most preferred behaviors, habits, customs etc of society. By not following what society most prefers, one would be effectively excluded from the group and thus culturally ‘unfit’. In the words of Sir Peter Gluckman human group exclusion is “the worst” form of punishment receivable. Humans are social animals. Most human development occurs post-birth. Therefore most of our brain development occurs also post-birth, with much of it under the impact of the environment. We rely heavily on human relationships as infants and really throughout our entire lives.


In contrast, the transmission of information in biological evolution is vertical, as genetic information is passed on over generations of offspring, through genetic information by means of reproduction. Evolution of a species operates to ‘match’ an organism to a particular environment at a particular time, and this matching is dependent only on reproductive success – i.e., the ability to successfully pass genetic information from one generation of offspring to the next. In fact, the ‘matching’ process is the natural selection by which evolution progresses. Phenotypic traits most suited to the environment will be selected for, as those who posses them successfully reproduce. Deleterious traits are put under selective pressure to be excluded from the species. Therefore, fitness in biological evolution refers to how well suited an organism is to their environment to pass their genes on to their offspring.


In conclusion, cultural evolution is significantly different to biological evolution. While biological evolution concerns itself primarily with reproductive success for the purpose of transmitting genetic information to the next generation, cultural evolution involves the transmission of the most preferred social behaviours, customs and habits both between generations and within the same generations. Though at first it appears they are distinctly separate, biological and cultural evolution are strongly linked. Certain behaviours that are learned in a social group become the traits upon which natural selection can act. Thus biological evolution can be advanced by cultural evolution.

LENScience

Thank you for your contribution and well done for making your first post on the Wiki. Your answer includes the key points asked for in the question, covering the differences well. More points could be covered to show similarities. To balance your paragraph on cultural evolution, while information can be passed horizontally, you should recognize the role of information being transmitted vertically influencing overall cultural evolution. Make sure you select the correct biological terms to use. In this context “variable” is not the appropriate term to use; perhaps you mean “behavior”. To help write a succinct answer, describe clearly the correct meaning of your selected biological terms within your answer e.g. describe the difference between transmission vs inheritance of information.



A.Heyes-Horowhenua College-12:55 21/06/11 What he said.


Biological and Cultural evolution are processes that involve change in an individual that is transmitted to the species due to the improved survival chances of the individual by having the new trait. The differences between these two forms of evolution lie in the manner in which the evolution occurs, is transmitted to the species, and is selected for.


In biological evolution, the cause is mutation of genetic material in an individual. In most cases, this would be harmful, as the body runs according to the correct functioning of every gene, relying on the other genes. However, occasionally, a mutation will occur that provides and individual with improved survival chances, increasing their likelihood of reaching reproductive age and producing offspring with the gene who reach reproductive age. The mutation eventually becomes a permanent characteristic of that species. This method of transmission is severely limited by the time it takes for the material to be passed on, as the mutation, or ‘information’ is transmitted via the passing on of genes. This is a slow process, meaning that biological evolution can only occur over great time periods. In contrast, cultural evolution is much quicker, due both to its cause and its method of transmittance.


Cultural evolution is a change in the culture of a species, such as language, beliefs, traditions or societal structure. These changes are not determined by random mutation but by innovation, the development of a concept or idea over a period of time until it is effective and can be transmitted to the rest of the species, until it forms a permanent characteristic of the species, just as much as a biologically evolved trait. Cultural change is caused by need for improvement, but instead of the improvement leading directly to increased likelihood of survival, it first leads to better societal function, allowing groups to better exchange information, defend one another, and interact positively. This in turn will improve the survival and reproductive chances of the overall group rather than individuals.


Cultural evolution is transmitted by word of mouth, direct communication between members of species within the same generation, which is both caused by and causes many of the traits of cultural evolution. The transmission of cultural evolution is extremely fast, as it can occur within a single generation. Because of the speed in which it occurs, it has allowed the human species to rapidly change over a relatively short period of time, allowing for ever increasing group size, the existence of a variety of roles in society, as less providers are required as group size increases and resource collection improves, and the increase in rate of transmission of ideas. This increased speed of transmission has meant that more ideas are produced every generation, so means of transmitting cultural evolution have improved and accelerated, allowing for transmission to become more rapid. This cyclical route for cultural evolution means that it constantly accelerates, while biological evolution must be transmitted at the same rate for species that currently exist.


The means of selection for both forms of evolution is again dissimilar, despite the fitness the evolution supplies is similar in nature. Both biological and cultural evolution overall improve the likelihood of survival for a species, and the likelihood that they will produce offspring that reproduce. This improvement is termed an increase in the fitness of a species, and both forms of evolution are based around this increase. In Biological evolution, the form of selection that decides whether a trait has made an individual fitter is that of Darwin’s ‘Theory of Natural Selection”, through natural competition. A biological mutation endows an individual with the ability to better compete with other individuals for resources, mates and nesting sites. This leads to those more likely to win these competitions surviving and reproducing over the rest of the species, until eventually the gene is found in every member of the species, i.e. all those without it have been out-competed due to lesser fitness.


In contrast, cultural evolution depends on social selection rather than natural selection. An innovation survives if it is the best form of that innovation available, and this is judged by the members of that group, who are able to take on or leave an innovation, depending on its apparent usefulness towards improving group structure; eventually improving the survival and reproductive chances of the group. Because the selection is made consciously, and becomes a learned trait, it can be selected for within a generation, and disappear or be improved upon very quickly, unlike that of the genetic mutation of biological evolution. In recent times transmission of cultural evolution is so fast, due to the development of newer electronic methods of transmission, that, based on inference from previous experience as to whether the innovation will be useful, the ideas can change in days, and be applied efficiently across all of the human species.


Biological and cultural evolution work on the same principles, of increasing the fitness of a species through changes to the species over time, through transmission of a single individual’s variation to the rest of the species, but cultural evolution has a much faster rate of transmission due to the nature of transmission,and the cycle of improvement cultural evolution brings to its method of transmission. This has led to cultural evolution have a far greater relevance and impact over a shorter period of time. This brings the question of whether biological evolution has any impact on human evolution anymore, as cultural evolution can move so much faster to improve the fitness of our species.

LENScience

Thank you for your contribution. Your answer presents information in an organized manner to address the question. You have given clear descriptions of what cultural and biological evolution are, the difference in the rate at which these occur and why. Try not to make the assumption that if there is change then it is beneficial. There is some confusion in the use of the terms adaptation with improvement, and it is unclear at times what is meant by fitness and survival; which are not necessarily the same. Your reference to the rate of cultural evolution is not clearly linked to either fitness or survival. You have linked evolution to an improvement which increases fitness. This places a value judgment into the context of evolution. What is deemed “fit” it is not necessarily “new and improved”. Evolution is the result of selection, not the cause for improvement.



J.Young @ Horowhenua College , 22/06/11 10:22 pm ^^

The evolution of humans throughout many generations can be expressed by the resultant of both biological and cultural evolution acting simultaneously. The modern humans today have arisen from these two types of evolution – both which have similar purposes in that it aids in the advancement of the human era, but also differences via its mechanisms in which they achieve this. Culture is knowledge, and the only way it can be acquired is through learning and experience. This evidence suggests that in order for any form of cultural evolution to occur in the early humans, they must have possessed a sufficient learning capacity or potential. Hence, sufficient brain enlargements must have developed in the early humans by biological evolution before any cultural evolution could be of any real significance.


The various cultures such as our beliefs, behaviours, habits, and values which are shared today can be thought of as the social aspects of human society. This is the product of hundreds of years of cultural evolution acting upon us Humans. Unlike biological evolution, the transmittance of information for cultural change is passed down to the next generation purely by experience and learning, or more specifically by intraspecific social interactions (i.e. direct communication), rather than acquiring it at the moment of fertilisation (the transmittance of genetic information). In humans, cultural change acts in a sense that there is no specified direction, and determines ‘freely’ which individuals it acts upon. This is because cultural information is acquired at any stage of life, and is continually updated throughout the individual’s life. This means cultural information can be transmitted to any number of individuals within the same social grouping, and regardless of their generation, even from youth to elderly, at a relatively fast rate. Whereas genetic information is limited to only acting downwards from the previous generation to the current i.e. parents to offspring. Hence, the transmittance of genetic information is much slower than the transmittance of cultural evolution, and can only move down to the next generation, and is also less prone to change - unless mutations occur within the individual.


When genetic information changes in an individual, it does so randomly and can occur at any stage of life i.e. at birth, via exposition to mutagens. It is called a mutation. Mutations are permanent and the individual is ‘stuck’ with it for the remainder of his/her life. Whilst a change in cultural information can easily be reverted by discipline and training. Therefore genetic change acts in a non-directional sense, with no ‘intent’ or ‘aim’ to fulfil as the genetic change is random. Also, it is only by chance that the mutation is beneficial to the individual, and offers a selective advantage via Natural Selection for the individual, allowing it to compete and adapt better than those without the mutation. Thus genetic change is determined purely on luck alone.


In cultural evolution, a change in cultural information is responsive to society’s standards and also to future needs, making the change purposeful. The selecting agent for cultural evolution would be society itself, where the most favourable traits are selected for, in this case individuals which display these behaviours would be ‘praised’ upon, and others would be encouraged to learn this and pass on to other individuals. Whereas individuals which display the least favourable traits would be ridiculed by his/her peers, and discouraged from passing it on to other individuals.


The fitness of an individual is defined as their relative breeding success. Both cultural and biological evolution of a species acts to improve each individual’s fitness, therefore both cultural and biological evolution are built around the same concepts, where the individuals which are better adapted to the physical and biological environmental factors (i.e. competition for food/resources, temperature, light) will survive to reach sexual maturity and reproduce - are considered more biologically evolved or more fit; is equivalent to those individuals which display favourable traits among social groups and are acknowledged for it, hence they feel ‘socially accepted’ and are considered ‘culturally fit’. Both types of evolution have selectors which continually shape the current and future generations by improving each individuals fitness and ability to adapt to the ever-changing environment, though society can be a more ‘tolerant’ and ‘forgiving’ selector than Natural Selection. For example, if a species possesses inferior physical traits compared to other species with similar needs, than that species will be considered ‘unfit’ and members of that species will be unable to compete as well with members of the other species for food or resources, hence members of that species have a lesser chance of surviving until maturity – Gause’s exclusion principle; as opposed to being socially ‘unfit’ where the consequences are much more minor, and cultural change is able to aspire.


In conclusion, the transmission of cultural information is more open and widespread than genetic as it is not limited to only future generations but all generations, it is able to occur at much faster rates than genetic and can be subjective to purposeful change once acquired. Both cultural and biological evolutions have the same objectives in that they aid in advancing the survivability and fitness of each individual in future generations over time by ensuring the most superior traits are selected for and passed on, and the inferior traits are selected against and excluded from the species.

LENScience

Thank you for your contribution. You are to be congratulated on the quality of your answer. You have addressed all parts of the questions, showing a sound understanding of the underlying biological concepts. This has been developed into a well organized and coherent discussion. One area that you do need to correct is in the 5th paragraph where you say “For example, if a species possess inferior physical traits….” Evolution does not act on the species and is not a unit of selection. Selection acts on the individual resulting in changes in the variation observes across species.