Logical Reasoning

PT150 · S3 · Q15 Carrillo: Using the number

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Carrillo: Using the number of existing primate species, along with measures of the genetic diversity among these primates and among the extinct primate species, our statistical model strongly supports the conclusion that the first primate developed around 81.5 million years ago.

Carrillo's Claims

1. Our model strongly supports the conclusion that the first primate developed around 81.5 million years ago.

2. (implicit): Our model used the number of existing primate species, along with measures of the genetic diversity among these primates and among the primate species.

Olson's reaction

1. Your model does not strongly support that conclusion. Your 81.5 million year guess is sheer speculation.

2. (implicit): I put more faith in our oldest discovered fossils than I do in your statistical model which just used the number of existing primates and the genetic diversity of living and extinct primates.

Evaluate

This is an unusual Disagree question since the 1st speaker only makes one claim. Lucky for us, that is the claim the 2nd speaker seems to quarrel with, but we have to dial in the language of the disagreement.

Goal

It looks like it's "strongly support" vs. "sheer speculation", in regards to this statistical model based on quantity and diversity of primate species.

Though we could also probably say it's a case of vs. "known fossil evidence", in regards to which type of data is more trustworthy.

15.

The dialogue provides the most support for the claim that Carrillo and Olson disagree over whether

  1. primates have been around for

    Unsupported Disagree Position

    We can't support the Disagree position, "Primates have not been around for more than 55 million years". The 2nd speaker isn't saying that 55 million years is definitely the beginning of primates. He's just saying that it's sheer speculation to think it's 81.5 million years ago. In other words, Olson would say, "I don't know how long primates have been around. It's at least 55 million years, since we have fossils that old, but I do not trust this crazy-different number your statistical model came up with."

    23% picked this

  2. Correct

    Carrillo's statistical model is a

    Why this is right

    The notion of whether or not this model is a reliable way speaks to the mismatch we located between "strongly supports" and "sheer speculation". We can infer that Carrillo would agree because the thinks this model strongly supports a conclusion about the first primates. And we can infer Olson would disagree since he says, "your estimate is sheer speculation, given a completely different number we get from a more reliable source of information".

    Skill tested: Agree/Disagree · how this choice captures the argument's function is the move to repeat next time.

    69% picked this

  3. the available sample of primate

    Both Positions Unsupported

    We can't infer whether either person thinks that the available sample is representative of the variety that have existed, since neither person speaks to that concept. Carrillo would be the closer one to believing this, but he doesn't need the available sample to be representative for his model to provide strong support. As long as he knows how to weight the un-representativeness of his sample, he can still have an accurate model. (Pollsters can talk to 2000 people and realize that certain factions of the population are under-represented in their sample, but then they compensate for this by making those data points count for more than just one data point.)

    2% picked this

  4. the dating of the primate

    Unsupported Disagree Position

    Olson would probably agree to this, but can we derive that Carrillo would say "those fossils you're referring to have been incorrectly dated at 55 million years old"? Definitely not. First of all Carrillo never talks about those fossils at all. Secondly, he's only talking about when the first primate developed, not whether the carbon dating on existing fossils was done properly.

    3% picked this

  5. fossils of the first primate

    Unsupported Agree Position

    We wouldn't be able to derive this from either party's statements. Carrillo, if he trusts his 81 million year estimate and knows that the fossils are 55 million years, might think "those 55 million year old fossils aren't the fossils of the first primate species". But would Olson say, 'yes they are. The oldest primate fossils discovered so far are fossils of the first primate species'? We have no idea, but it seems like by saying "so far", Olson is allowing for the possibility that we'll discover even older fossils, so he'd likely be receptive to the possibility that these 55 million year old fossils we have aren't from the very first primate species.

    2% picked this

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