Humans and chimps, for example.
And one or two sea lions.
2 Likes
No, I cannot. Chiefly because I do not know how to meet the âsimilar genetic makeupâ criterion, outside of naming two base-for-base genetically identical organisms, and even then Iâm not sure youâd recognize them as related without a birth certificate claiming as much.
2 Likes
I wouldnât, as humans exhibit both different gene arrangements and different chromosome counts. Have you really never heard of Down syndrome?
How about similar enough so they can produce fertile healthy offspring. We certainly can test if the offspring is fertile or has conditions like Down syndrome. As we can also tell the difference between genes that have a completely different function and genes that have the same function but are functional variants.
So âsimilar genetic makeupâ is the same as âreproduce fertile offspringâ and not a separate criterion after all.
(I expect that by now Bill has forgotten that he introduced it as another possibility that was supposedly different from âreproduce fertile offspringâ)
Similar genetic make up is a condition that leads to producing healthy fertile offspring.
Thatâs right.
Unfortunately, we started with the following conversation:
AnEvolvedPrimate: What would constitute an empirical demonstration of common ancestry or a reproductive connection between species?
colewd: There are many possibilities here but a start would be if two species could reproduce fertile offspring.
AnEvolvedPrimate: What are the other possibilities?
colewd: Matching chrome counts and gene types are additional evidence of common ancestry.
But if the way to check whether two species have matching chrome [sic] counts and gene types is to see if they reproduce fertile offspring, then thatâs not a different empirical demonstration, is it?
Iâm picturing Bill working in Pizza Hut:
Bill: Weâve got lots of different pizzas available today!
Customer: Such as?
Bill: Well, thereâs ham and pineapple.
Customer: Sounds good! What else have you got?
Bill: Hawaiian
Customer: Whatâs that?
Bill: Itâs a Canadian recipe, from Ontario.
Customer: But what is it?
Bill: Ham and pineapple.
Customer: UmâŚ
Bill: Then thereâs our Australian special.
Customer: Oh?
Bill: Yes, this one was the most popular pizza in Australia in 1999.
Customer: Bonzo, mate! Throw another shrimp on the barbie! Whatâs on it?
Bill: Ham and pineapple!
Customer: But thatâs⌠Never mind. Have you got anything else?
Bill: Of course! We have lots of pizzas available.
Customer: Whatâs the next option?
Bill: The next option?
Customer: Yes, youâve told be about the ham and pineapple. What else is there?
Bill: You want another option?.
Customer: Yes please
Bill: Well, thereâs HawaiianâŚ
Other people can remember what you wrote, even if you canât.
4 Likes
No, I cannot name two species that are unable to produce viable offspring whilst at the same time being able to produce viable offspring. Congratulations: You argued yourself into incorrigible, unfalsifiable, definitional correctness, which has nothing to do with biology anymore. Best of luck with what ever this is supposed to accomplish.
2 Likes
You can separately check chromosome counts and gene types. It is a separate observation.
If one is the cause of the other the effect that does not make them the same piece of evidence.
But I canât, because your proposed method for seeing whether the chromosome counts and gene types are sufficiently similar is (drum roll)âŚ
Round and round and round we goâŚ
2 Likes
Yes you can Roy it is publicly available data.
You can do hypothesis testing here to see how similar you need to be to get fertile healthy offspring. You are clearly examining two different pieces of evidence to see if you can isolate the cause.
It started even before that with Billâs bizarre claim that in studying extant populations, biologists were using a âseparate origin modelâ by default.
I still have no idea what a âseparate origin modelâ is even supposed to entail, because Bill has been maddeningly vague on that subject.
So you can either
1: See if the two populations produce healthy fertile offspring.
2: See if the two populations have sufficiently similar chromosome counts and gene types to produce healthy fertile offspring - by seeing if the two populations produce healthy fertile offspring.
Letâs assume for argument sake we can test of all of this and determine whether individuals can mate and produce fertile healthy offspring.
You still have a whole pile of problems and edge cases to deal with:
-
This appears to assume strictly sexual reproduction in testing whether individuals can mate with one another. However, there are various modes of reproduction that donât depend on individuals directly mating with one another.
-
You can have cases where individuals in populations can be infertile. This can include individuals that are naturally infertile (worker ants for example) or may be infertile due to individual abnormalities. If youâre trying to use individual fertility as a test for common ancestry, you would rule out common ancestry in those cases.
-
In the event a population of organisms being created, individuals within that population would be presumed to be able to mate and produce fertile healthy offspring. However, if the test for common ancestry is seeing whether individuals can mate and product healthy offspring, therefore tests on such a population of created individuals would result in concluding common ancestry between those individuals.
Case in point would be Adam & Eve. If Adam & Eve were created individuals, but capable of mating and producing healthy offspring, therefore we would conclude (per your criteria) that Adam & Eve share common ancestry.
Itâs not clear how you define or distinguish a separate origin event. Merely testing for fertility and reproduction isnât going to get you there.
1 Like
-
Individuals with different chromosome counts can frequently mate and produce fertile offspring, as can individuals with different genes.
-
Interfertility is not a sharp line, yes or no; it has all sorts of intermediate states. There is even the occasional fertile mule. So this supposed test is actually evidence for gradual loss of fertility in separated populations with common ancestry.
1 Like
I agree that certain cases will work better than others.
Thatâs not what Iâm saying though. Iâm saying that you donât have any cases that work at all.