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Post by creature386 on Oct 30, 2023 16:01:21 GMT 5
So the concept of extinction due to being outcompeted has been getting discussed a fair bit recently. (You likely know why.) How did such narratives come to be to begin with? Is it because we have wiped out species? Actually, this narrative goes way back to Darwin. Darwin observed that organisms differ in their traits and that some are more adaptive than others. Experimental evidence later got gathered by Gregory Gause who observed two species of bacteria called P. aurelia and P. caudatum. He observed that each of these bacteria grow fine individually, but when you put them in the same petri dish, P. aurelia will flourish and P. caudatum will perish.  Source: cnx.org/contents/GFy_h8cu@10.53:rZudN6XP@2/IntroductionYou can also read Wikipedia's article on the competitive exclusion principle:
As Infinity Blade noted, you need a lot of data on two species geological ranges and ecological niches to prove that competitive exclusion occurred in the fossil record, but it is an established principle.
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Post by Infinity Blade on Oct 30, 2023 19:28:17 GMT 5
If something appears in a fossil record right when another disappears, you have what appears to be a correlation. If those two species seem to share a niche, you might think at first glance that one outcompeted the other (as it appears/becomes more common at the expense of the other). The problem, though, is that you need a lot more data for outcompetition to be solidly supported. Like for example, do the dates actually line up? To follow up on this, I want to mention something else. Another problem with purported (as opposed to demonstrable, like creature's example) examples of outcompetition is that most of the time, people can't name a reason as to why one species would outcompete another. For one species to completely outcompete another to extinction (at least in a given area) requires that the former be able to procure resources and nutrients better than the latter. For instance, why would a sabertooth outcompete a terror bird? What does the cat have that is so incontrovertibly superior to anything the bird has that the latter cannot adapt to or be better itself in different evolutionary contexts? In creature's P. aurelia vs P. caudatum example, we know why the former is able to outcompete the latter when together. P. aurelia uses the same resources faster, allowing it to reproduce more rapidly, and it also (apparently) happens to produce toxins that are lethal to P. caudatum. But what comparable advantage does a carnivoran have over a terror bird? Or early orcas against megalodon? Or birds against pterosaurs? You can't really name anything. |
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Post by Exalt on Oct 30, 2023 20:32:51 GMT 5
I heard just the other day about the orcas vs. Megalodon narrative. I was a bit surprised by that one. Surely, orcas can make do on smaller prey items than Megalodon? I don't know, it sounds like the equivalent of comparing wolves to Allosaurus, or something.
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Post by Exalt on Nov 1, 2023 5:58:08 GMT 5
So I think that Infinity Blade and I briefly discussed this once, but of the animals they shared ecosystems with, what do we think that Smilodon would have actually hunted? There seems to be some degree of debate, such as for bison.
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Post by Infinity Blade on Nov 1, 2023 8:12:34 GMT 5
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Post by Exalt on Nov 1, 2023 23:15:40 GMT 5
I will look into them, thank you
This next question may sound very foolish: why don't animals that are swallowed whole...do anything to the predator?
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Post by Exalt on Nov 3, 2023 2:32:37 GMT 5
Another round of questions: How does sexual selection work? IE, how can traits be transmitted to one sex and not the other.
Does the Marsupial method of reproduction have any sort of advantage?
The American Ornithological Society announced recently (I just happened to run into this article) that it would be giving new common names to species whose common names are named after people. Do you all have any thoughts?
Additionally, how do we feel about "Old World" and "New World" terminology? (New World Monkeys, etc.) It sounds a bit Eurocentric, even if technically, the old world seems to be anywhere that isn't the Americas.
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Post by creature386 on Nov 3, 2023 2:48:47 GMT 5
Another round of questions: How does sexual selection work? IE, how can traits be transmitted to one sex and not the other. It seems like your question is mainly about inheritance, so I'll address that. We have to distinguish between sex-linked and sex-limited traits. Sex-linked traits are those that are inherent to a gender and tend to be related to the gonosomes (X and Y chromosomes). For example, if there's a mutation on the X chromosome, it tends to affect males more strongly, as they only have one X chromosome, while females might have an unmutated one that will cover the mutation. Sex-limited traits are different. These are genes that are present in both sexes, but that are expressed differently or that might only be expressed in one gender. For instance, female humans can have the genes for prostate cancer, but since they don't have a prostate to begin with, they can't express it. |
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Post by Infinity Blade on Nov 3, 2023 4:21:25 GMT 5
The American Ornithological Society announced recently (I just happened to run into this article) that it would be giving new common names to species whose common names are named after people. Do you all have any thoughts? While I think we probably should get rid of problematic eponyms, I don't think it's necessary to get rid of the entire concept altogether. Not all people with species named after them were terrible people. Sure, we might save ourselves some headache by going "f*ck it" and wiping the slate clean of all eponyms, but we'd be getting rid of those where it might be legitimately deserved (or at least, acceptable), which I don't think is fair. Besides, we'd be saving ourselves even more headache by just doing nothing about it at all. Any possible outcome we have through this entire endeavor exists on a sliding scale of practicality vs what we think is right. But I'm going to be completely honest with you: at the end of the day, these are just names. If the AOS wants to get rid of all eponyms*, big deal. I really couldn't care less if Anna's hummingbird is called something else. And hey, it does get rid of some problematic names, which I consider a plus, if anything. However, I'm also not going to stomp my foot in fury if we do absolutely nothing about it, and some species remain named after people we'd regard as assholes today. I mean, let's be real here: who honestly looks at "Verreaux's eagle" and feels their heart sink out of the feeling that they are being excluded from ornithology (or biology in general)? If there was any issue where we could waffle around on arguing which eponyms deserve to stay or not, it's this. The origins of biology as a field may be laced with sexism and racism, but it's not like a woman or a person of color is going to spontaneously explode for every minute that Audubon's shearwater and other names like it are still in use. And I say this as Asian-American myself. I'm a paleontology enthusiast, but I am also exactly the kind of person the AOS claims they are being more inclusive towards with this move. Yet I read names like Archaeotherium mortoni or Marshosaurus, and I don't quake in my shoes, well up tears in my eyes, and then fall to the floor sobbing as I see the name of some 19th century white dude who would've regarded me as an intellectually inferior *insert racial slur here*. TL;DR: I really don't care that much what they do. *Though, it's questionable if the AOS really has that right, as I've seen argued. In fact, the fact that they think they have that power may just be arrogance on their part. |
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Post by Exalt on Nov 3, 2023 5:48:09 GMT 5
To tell you the truth, I don't know know very many examples of ones based on controversial individuals to begin with, nor do I know how this works.
I should also note though that that's not the exclusive expressed motive: there is also the idea that the names should actually describe the species.
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Post by Infinity Blade on Nov 3, 2023 6:18:19 GMT 5
To tell you the truth, I don't know know very many examples of ones based on controversial individuals to begin with, nor do I know how this works. I should also note though that that's not the exclusive expressed motive: there is also the idea that the names should actually describe the species. Yeah, I'm aware. I think both arguments are sound, although I wonder if there are any cases where an eponymous species looks very similar to another one, and it might be an issue coming up with an actual descriptive name. |
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Post by Exalt on Nov 3, 2023 7:13:33 GMT 5
That may be a good point.
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Post by mechafire on Nov 7, 2023 3:57:13 GMT 5
 Why do beaked whales have such tall spinous processes? |
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Post by Infinity Blade on Nov 7, 2023 6:02:44 GMT 5
I'm having trouble figuring out why. That's a useful adaptation for the attachment of muscle or ligaments, but I don't know what specifically is attaching to there (if anything) and why. I did, however, find out that the relative height of the spinous processes gets larger as the animal grows. Seems to be a weird quirk of their biology. www.icrwhale.org/pdf/SC0241-34.pdf |
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Post by Exalt on Nov 9, 2023 3:08:31 GMT 5
1.Why is it called the KPG event and not the CPG event?
2. How might Thylacoleo mothers have provided for their children while still in the pouch? Hunting that way sounds very risky. I tried looking into the Thylacine to find a point of comparison, but was unsuccessful.
I've considered a few possibilities, but any thoughts?
EDIT: I knew I was missing something here, and I realized that I didn't even think about how pregnant placental predators get by. Now I just feel stupid.
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