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Animal Fact of the Day

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The Phantarch
406551.  Fri Sep 12, 2008 6:00 pm Reply with quote

Who says that evolution is always beneficiary?
Sometimes it's detrimental, like dinosaurs evolved into our everyday birds, I don't envy the ones that evolved into chickens and as sharks will proudly testify, often as not, there's no need to evolve if you're perfectly suited to your environment.

 
CB27
406823.  Sat Sep 13, 2008 1:59 pm Reply with quote

Evolution isn't about benefit.

If a member of your species is born with a certain mutation and successfully breeds and their offspring inherit that mutation and also breed successfully you get an evolutionary step.

If that mutation is either unappealing to the other sex or helps predators catch them more easily then chances are that anyone with that mutation will eventually die out and that evolutionary step will be avoided.

 
HerrBen
407458.  Sun Sep 14, 2008 6:26 pm Reply with quote

Just because sharks haven't changed much in a while doesn't mean they have stopped evolving, it just means they've done a good job of it. They're evolving as fast as their enviroment demands.

 
bobwilson
407465.  Sun Sep 14, 2008 7:02 pm Reply with quote

Reading HerrBen's post made me think - there should be a mathematics of evolution.

Given (for example)

a population (p),
a probability of change of the organism per generation (g),
a probability of a change in g giving benefit (b)
a probability for stasis of the environment inhabited by the population (e)

it should be possible to work out some basic equations.

For instance, if you factored all of the above in to an equation you'd have something like the probability of the survival of a particular species.

Well, it's just an idea but it makes sense to me. Something like Drake's equation for the possibility of ET life - except that we could probably fill in a lot more of the figures.

Any clever maths / biology students out there? Or has this already been done somewhere?

 
CB27
407659.  Mon Sep 15, 2008 7:21 am Reply with quote

The problem for this is exponentiality which is where co-evolution comes to play.

Hummingbirds are a brilliant example. Specific species of hummingbirds have evolved with bills which are long enough to feed on nectar of flowers they frequent. Mutations along the line will undoubtadly throw up the occasional bird with a longer bill, but it's not useful for the flowers they feed on so either that mutation dies out with that bird or it finds another type of flower to feed from and breeds a new sub species.

 
scottydog
407661.  Mon Sep 15, 2008 7:26 am Reply with quote

OK, does anyone know why, say, camels evolve with different number of humps?

Is there some evloutionary explanation or is it just something genetic that has happened?

 
CB27
407670.  Mon Sep 15, 2008 7:43 am Reply with quote

I know the camel toe evolved after a ferocious wedgie...

 
HerrBen
408002.  Mon Sep 15, 2008 7:01 pm Reply with quote

Evolution has to be my favourite topic for banging on about but there's far to much typing involved and I'm a bit stoned so I'll save them.

On Bobs question on a mathmatical formule they have just finished doing that, (if the press boomph is to be belived) there's that new virtual universe style game out called Spore, you start off as a single cell job and evolve to space flight etc. Obviously there's the entertainment value programed in but for the money they've spent on it I think it's as good as your going to get.

 
Zebra57
678084.  Wed Mar 03, 2010 9:27 pm Reply with quote

This extract may shed some light on the duck.

"The Argentine Blue-bill or Argentine Lake Duck (Oxyura vittata) is a small South American stiff duck. What's paradoxical in this equation is that most birds do not even have a penis, except ostriches (and related groups, like kiwi and tinamous), ducks, geese and swans.

Bird penis in flaccid state curled up inside the cloaca. Well, a specimen of Argentine blue-bill duck had a remarkable 42.5 cm (17 inches) long penis (photo center) (the average length of this species is 20 cm (8 inches))!

The flaccid penis is coiled but fully erect is twice the size of the bird: it is like us having a 3.5 m (12 feet) penis..."

http://www.who-has-the-biggest-penis.com/

 
Zebra57
827425.  Tue Jun 28, 2011 6:23 am Reply with quote

You may find these links QI

http://www.youtube.com/watch?v=Bjs2w3jdTHA&feature=related

http://www.youtube.com/watch?v=NxxbQVKM1Xw&NR=1

http://www.youtube.com/watch?v=dhe3Hy7Q2GQ&feature=related

 
Chowchilla
947528.  Fri Oct 26, 2012 4:21 am Reply with quote

scottydog wrote:
OK, does anyone know why, say, camels evolve with different number of humps?

Is there some evloutionary explanation or is it just something genetic that has happened?

Two extant camel species have humps (Arabian- one; Bactrian- two), but the majority have no hump at all (Guanaco, LLama, Alpaca and Vicuņa). There are many fossil camel species and the evolutionary tree suggests these animals evolved in North America where they flourished for millions of years before spreading to South America (when the land bridge formed) and Asia.

It seems that it is only in the last couple of million years that some species have adapted to extreme climates (all the extant species) so it's reasonable to assume that the hump evolved at the same time, but no-one really knows for sure, because we have no way of knowing if the extinct forms had humps or not. This is because we do know that the hump is used as a fat store. We also have no convincing explanation as to why the South American ones didn't evolve humps.

So the truth may be that 'nobody knows'.

 

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