Cannot wait for this, looks fascinating. SS thoughts?
BBC - BBC Two Programmes - Horizon, 2010-2011, Are We Still Evolving?
I think they probably use the word 'evolving' pretty loosely. If it simply means 'Is our genetic composition changing as a species?' The answer is probably but it's not an issue that can be answered given the long periods required for changes in populations to be identified, and considering the changes in life expectancy, lifestyle and other constraints from just 100 years ago when there were no antibiotics for example (and 100 years being a meaningless amount of time in an evolutionary sense), what then held true in terms of evolutionarily guided direction, simply does not hold true now, further making it impossible (not merely improbable) to speculate on any future direction.
And anyway, without the same restraints (and connection) on and between survivability and breeding as we would have as roving bands of isolated small population groups, I don't think the term in the traditional sense applies.
I'd be interested in what it says though. I guess it'll be thin on science, high on speculation (plenty of those on the discovery channel here in the US). But I'd like to have a look or hear about it.
Last edited by silentstriker; 28-02-2011 at 04:56 PM.
wheres the maths thread gone?
When people say 'evolution takes millions of years', are they strictly referring to stabilising selection? Surely some forms of directional selection can take place and change the frequency of alleles in a pretty big way in a much shorter period of time than that?
How exactly does catalase catalyse the breakdown of hydrogen peroxide? I know all about the lock & key model of enzyme action and all that, but can anyone tell me in terms of electrons and bond breaking/making how it actually lowers the activation enthalpy for the reaction? Thanks.
Catalase breaks down hydrogen peroxide in two steps. A hydrogen peroxide molecule is broken apart, with an iron ion in the catalase latching onto an oxygen molecule. The rest of the hydrogen peroxide molecule (H2O2) is set free as water (H2O). Then another hydrogen peroxide molecule is broken apart, with the same iron ion breaking off an oxygen atom, to be combined with the first detached oxygen atom, to be released as oxygen gas (O2).
Thanks a lot mate, you can now be entered as a reference in my chemistry investigation, how's that for kudos!
1. dude on an internet forum, alias blahblahblah
I'd love to get a report with that citation. I'd frame it. And congratulate the student for having the balls. And then I'd fail him out of school.
They really don't give a **** about where the reference came from, as long as you have one. Pretty sure they don't even check them.
I do . Some dude said so would usually not result in a very good outcome for my student. But you're in high school, so I suppose they overlook a lot more.
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