It is reasonable to say that Humans have not been around for 200,000 years

My opponent has made the following arguments: 1. Extrapolation of data from the past 300 years is a valid method to use for prehistory. 2. That the average 20 year life span mentioned in my previous argument "may or may not be correct" even though a citation was listed 3. The debate title is: "It is reasonable to say that Humans have not been around for 200,000 years". However, now he is changing the format to include hominids who lived 4M years ago+: "But actually, this new information creates more problems for you. If 10 billion hominids lived during the 4,000,000 -200,000 years period...then you are going to have even more people (descendants of the 10 billion) added to the impossible amount of people that would have existed from 200,000 years till now." Humans evolved approximately 200,000 years ago. Prior to 200,000 years ago, only hominids and transition/divergent species walked the Earth. The topic is directed towards humans, not hominids, which is an entirely different area of research. The following is the abstract from a research paper published by the Smithsonian Astrophyiscal Observatory, Harvard-Smithsonian Center for Astrophysics entitled: Agriculture, population growth, and statistical analysis of the radiocarbon record. "The human population has grown significantly since the onset of the Holocene about 12,000 y ago. Despite decades of research, the factors determining prehistoric population growth remain uncertain. Here, we examine measurements of the rate of growth of the prehistoric human population based on statistical analysis of the radiocarbon record. We find that, during most of the Holocene, human populations worldwide grew at a long-term annual rate of 0.04%. Statistical analysis of the radiocarbon record shows that transitioning farming societies experienced the same rate of growth as contemporaneous foraging societies. The same rate of growth measured for populations dwelling in a range of environments and practicing a variety of subsistence strategies suggests that the global climate and/or endogenous biological factors, not adaptability to local environment or subsistence practices, regulated the long-term growth of the human population during most of the Holocene. Our results demonstrate that statistical analyses of large ensembles of radiocarbon dates are robust and valuable for quantitatively investigating the demography of prehistoric human populations worldwide." https://www.cfa.harvard.edu... From this research we know that the human population growth from the Holocene (approximately 12,000 years ago) was determined to be .04%. The calculation for doubling at a constant rate is: Td = log(2) / log(1 + r) where Td is time of doubling and r is the constant rate. At a constant rate of .04%, the doubling rate would be 1750 years. The current population growth is 1%. If the population growth was .04% 12,000 years ago, the average growth rate per year up until the present would be .003%. Agricultural development and settlements arose during the Holocene, which allowed for greater sustainability of communities and a higher growth rate. Prior to the Holocene, population growth rate would have been considerably smaller given that humans were very gradually acquiring survival skills. Using the same formula above and assuming the rate of growth prior to the Holocene was smaller, if we divide the .04% by only half, which is highly unlikely over such a long period of time (200,000 years " 12,000 years = 188,000 years), the doubling rate would be approximately 35,000 years. As mentioned previously, linear extrapolation of current growth rates is invalid. This link explains exponential growth and doubling time calculations: http://www.cairco.org.... My opponent made this comment: "I do not know to much about the dating methods except that are used with certain assumptions about the world that may or may not have been true thousands of years ago." This statement is absolutely false. There are no "assumptions" - only hard data. I challenge my opponent to post a credible link to research that suggests that isotopic decay algorithms are incorrect. If that were the case, there would be thousands of dead patients whose doctors relied on diagnostic radiopharmaceuticals. My conclusion is as stated before. My opponent has presented no evidence which would support his position or contradict the current scientific literature.