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Author Topic:   Is evolution of mammals finished?
PaulK
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Message 2 of 213 (383623)
02-08-2007 5:24 PM
Reply to: Message 1 by MartinV
02-08-2007 4:50 PM


Perhaps it is not Broom's evidence that is outdated but his view of evolution ?

I note that you do not present a real argument from the data to Broom's claims. I can't tell on what basis Broom reached his conclusions.

Some facts to consider.

1) Taxonomy is based very heavily on life as it exists now. If biologists were assembling a taxonomy 30,000,000 years ago it is likely that some of Brooms Orders would not be recognised as such. Because - based on the species extant at that time - it would not be justified. Broom's data may be at least partially explained as a consequence of this.

2) According to the diagram you link to the new Orders have their basis in the aftermath of the K/T mass extinction event. This is a period where we would expect rapid evolution and disversification. Since there as not been another mass extinction event since then we cannot validly compare the data without making allowance for that fact.

How does Broom address these two points ? Does he address them ? If not, then why not ?


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PaulK
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Posts: 14959
Joined: 01-10-2003
Member Rating: 3.1


Message 8 of 213 (383791)
02-09-2007 8:23 AM
Reply to: Message 6 by RAZD
02-09-2007 7:49 AM


Order is above Family, which is above Genus. (There are a confusing array of subclassifications but that's the basic situation).

There is always a subjective element in taxonomy - even species is not completely objective (it's not unusual for a population previously considered a subspecies to be promoted to full species status).

I think the crucial point which we are missing is the argument supposed to support Broom's conclusions. We simply don't know how the evidence is supposed to show that Broom was right.


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PaulK
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Posts: 14959
Joined: 01-10-2003
Member Rating: 3.1


Message 25 of 213 (384438)
02-11-2007 2:59 PM
Reply to: Message 23 by Hyroglyphx
02-11-2007 11:40 AM


Re: Evolutions precipice
You do know that Ted Holden is not exactly a reliable source ? In fact a complete joke ?

And I beleive that I've already corrected you in earlier discussions on the point that many mutations are larger than a single nucleotide.


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PaulK
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Posts: 14959
Joined: 01-10-2003
Member Rating: 3.1


Message 98 of 213 (387707)
03-02-2007 3:06 AM
Reply to: Message 96 by MartinV
03-02-2007 1:30 AM


Re: Mobbing
According to this paper (only the first page and the abstract are freely available)


....mobbing by non-competitors was very rare (4/420 reports) and its consequences trivial.

So it seems that in Britain, bats are rarely mobbed by non-competing birds.


...Flying with aerial insectivorous birds was more frequent (19/420 reports) but antagonism was again uncommon

Even birds that directly compete with bats do not often attack them.

So I find the idea that there is any inherent drive in birds to attack bats implausible. It seems that in fact they do so only rarely, even when directly competing for the same food.


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PaulK
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Posts: 14959
Joined: 01-10-2003
Member Rating: 3.1


Message 102 of 213 (387771)
03-02-2007 3:58 PM
Reply to: Message 101 by MartinV
03-02-2007 3:47 PM


Re: Mobbing
quote:

If it is implausible than I see no reason why bats do not flight during day.

How about avoiding predators ? Accordign to the same study three times as many bats were attacked by predators as were mobbed by non-competing songbirds. Surely that is a better reason. Perhaps there is less competition for their preferred food, too.

quote:

If bats are not hunting by raptors as extraordinaly delicious food


Who says that they aren't ?

quote:

If songbirds are mobbing owls I don't know from what birds "judgment" or "reason" or instict it should be.


Owls and bats are very different. Owls are likely mobbed for the same reason that other raptors are mobbed.

quote:

Songbirds must somehow assume that owls are their competitors in insect feeding.


That IS silly. While the little owl - which does fly during the day anyway - largely goes for insects most owls are mobbed because they are potetnial predators of songbirds, not competition.
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PaulK
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Posts: 14959
Joined: 01-10-2003
Member Rating: 3.1


Message 106 of 213 (387778)
03-02-2007 4:55 PM
Reply to: Message 105 by MartinV
03-02-2007 4:38 PM


Re: Mobbing
quote:

So we should suppose that predators prefer somehow bats instead of other diurnal birds. Otherwise diurnal birds would became nocturnal animals too. Using darwinistic logic.

You mean using MartinV logic rather than actually considering all the relevant factors. I'd point out that bats are adapted to a nocturnal lifestyle and are thus better able to take advantag eof flyign at night to avoid daytime predators.

quote:

My point is this - humans do not like bats. It's old medieval tradition that bats were nailed on entry-doors down heads (only bats, no birds). This hatred has some psychological reason. I


Maybe it does. But it seems silly to invent the idea that birds have some strange antipathy to bats - in defiance of the evidence that they do not - to try and explain human behaviour. I guess that's more MartinV logic.
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PaulK
Member
Posts: 14959
Joined: 01-10-2003
Member Rating: 3.1


Message 110 of 213 (387793)
03-02-2007 5:59 PM
Reply to: Message 107 by MartinV
03-02-2007 5:16 PM


Re: Mobbing
SO he really said that you should pretend animals frequently engage in bhaviours that they very rarely engage in so that you can invent psychological motives for it ? If so then I can't see that his qualifications make the idea any less silly. If not, then of course he didn't engage in the MartinV logic I referred to.

Obviously you are no fan of Adolf Portmann or you wouldn't attribute such foolish thinking to him.

(Of coruse the part you quoted wasn't about psychology at all - it was about assumign that there are no explanations simply because you lack the imagination to think of even obvious possiblities. Again behaviour that cannot be justified by attributing it to something else0>


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